NN2381 SERIAL: IADC DULL GRADING /SEALS

Transcription

1 BIT RUN REPORT Run: 1 Customer: KNOC Ferhana Operating Company BIT: Y11 Well: CP-Ex1 RIG: XDEC/ZJ70 SERIAL: NN2381 SIZE (Inches): 26" TOP VIEW SIDE VIEW IADC DULL GRADING INNER OUT ER DULL 2 2 WT LOCAT ION A GAUGE OT HER REASON 1/16" PULLED In CT PR 4 Rig grade: 2-2-NO-A-2-1-NO-PR Re-runnable: NO DRILLED OUT SHOE: NO Repairable: NO RUN INFORMATION: DEPTH IN: DEPTH OUT: DRILLED: TOTAL HRS: ON BTM. HRS: TOTAL ROP: EFFECTIVE ROP: WOB: RPM: D.H.M. RPM: Torque: Total Revolutions: MUD: 12 m 309 m 297 m - hr hr m/hr 4.15 m/hr 5-16 tonne RPM - RPM Kftlbs 429 KRevs TYPE: MW: PV/YP: HYDRAULICS: WBM BHA: 26" RC Bit/9"Bit sub w/float/dc 9"/S. Stb 26"/DC 9"/S. Stb 26"/X-O/DC 8"/Jar 8"/DC 8"/X-O/HWDP 5,5"/DP 5,5" COMMENTS BRNG. /SEALS PPG NOZZ: TFA: FLOW: DP: Bit HHP: HSI: IF: NOZ.VEL: 3*20/32, CJ 1*16/ in GPM PSI Satisfactory 1644 Lbs. 283 ft/seg SURVEY: DEPTH: ANG. IN: 0 AZIM IN: 0 ANG. OUT: 2.8º AZIM. OUT: 174.4º DLS: 12 m 309 m The objective for new Y11 was to drill 26" vertical section from 12m till section TD at 508m. Currently the bit drilled 297m through layers of claystones, sandstones and gravels in the interval from 12m till MD 309m accumulating av. ROP of 4.15m/h. At the depth of MD 117m was pulled to surface to check dull condition of the bit, where neither damage to cutting structure nor balling issue was observed. Y11C was run back in hole to continue drilling. In the interval of m, ROP significantly dropped down to 1-2m/h, where decision was made to POOH to surface and change the bit. On surface Y11 was graded as 2-2-NO-A-2-1-NO-PR, whereas bit engineer graded it as 2-2 W T-A-4 - I- CT-PR. Cutting structures has exhibited normal wear and slight chipping, which should be due to vibrations. Major wear observed was bearing failure as Y11C (IADC 115) which is non-seal roller bearing milled tooth bit with aggressive cutting structure. Under normal drilling conditions service life for unsealed bearing is 500KRevs, where subject bit was rotated 429KRevs. Analysis of the run revealed that 1-1 cutting structure is well suited for subject formation as no significant wear on the cutting structure was observed and possible reason of low ROP was insufficient W OB. Low ROP resulted in long drilling time, which made Y11C not suitable for this application due to short bearing life. The W OB during the run was limited due to deviation problems. Subject bit can neither be re-run nor repared, due to bearing falure. Further usage of this bit may result in lost cone. Thus for future runs NOV Downhole recommends using milled tooth bit with IADC of 115 which has sealed roller bearing (bearing life over 1,000 KRevs) with pack holed BHA assembly to avoid hole deviation and higher W OB in the range of t to achieve higher ROP. LITHOLOGIES Sandstone 20 %, Claystone 80 % DATE: 27-Feb-12 Rig Manager: Drilling Supervisor:

2 BIT RUN REPORT Run: 1 Customer: KNOC Ferhana Operating Company BIT: Y11 Well: CP-Ex1 SERIAL: NN2381 RIG: XDEC/ZJ70 SIZE (Inches): 26" - Y11C has not reached section TD due to low penetration rate - Possible reason of Low ROP was insufficient W OB RESULTS - Bearing failed due to longer drilling time than planned and short bearing life, where bearing life for unsealed roller bearing bits is & 500KRevs under normal drilling conditions - Cutting structure has exhibited normal wear and slight chipping possible due to downhole vibrations - Cutting structure is well suited for subject application as no damage to cutting structure was observed after the run. - Use of Milled Tooth bit with 1-1 cutting structure for 26" hole size drilling in Chustpap field RECOMMENDATIONS - Use of Roller Cone bits with sealed roller bearing to have extended bearing life - Drilling with higher W OB in the range of 22-25t to achieve higher ROP - Use of packed hole BHA assembly to avoid deviation problems DATE: 27-Feb-12 Rig Manager: Drilling Supervisor:

3 RUN: CUSTOMER: BIT TYPE: 1 KNOC Fergana Operating Company T41 BIT RUN REPORT WELL NAME: CP-Ex1 SERIAL NUMBER: D RIG: XDEC6/ZJ70 SIZE(Inches): 26 IADC DULL GRADING INNER OUTTER DULL. LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 1 WT A E In NO TD RIG GRADE: 1 1 NO A F 1 NO TD RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 309 Meters TYPE: WBM NOZZ: 3x22/32, 18/32 CJ DEPTH OUT: 508 Meters MW: 9.8 PPG TFA: Sq. In. DRILLED: 199 Meters PV/YP: 12/21 Cp/Pa FLOW: 1100 GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: 71 Hrs BIT HHP: 376 TOTAL ROP: - m/hr HSI: 0.71 Satisfactory EFFECTIVE ROP: 2.8 m/hr IF: 1434 Lbs WOB: 6-18 Tons NOZ.VEL: 259 Ft/seg RPM: RPM D.H.M. RPM: - RPM TORQUE: Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 400 KRevs ANG. IN: 2.8 AZIM IN: Meters BHA: 26 RC Bit / Sub / 2 x 9 DC / 26 S. Stab / 1 x 9 DC / 26 S. Stab / ANG. OUT: 1.5 x-o / 9 x 8 DC / 8 JAR / 9 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; AZIM OUT: Meters DLS: LITHOLOGIES: Claystones 80%, Sandstone 20% with Gravel stringers DATE: _2 Mar 2012_ Rig Manager: Drilling Supervisor:

4 RUN: CUSTOMER: BIT TYPE: 1 KNOC Fergana Operating Company T41 BIT RUN REPORT WELL NAME: CP-Ex1 SERIAL NUMBER: D RIG: XDEC6/ZJ70 SIZE(Inches): 26 COMMENTS The objective for T41 was to finish drilling 26 vertical section from the depth 309m till TD at 508m. The bit drilled 199m of formation through layers of clay stone and sandstone with thin stringers of gravel accumulating av.rop of 2.8m/hr. Totally T41 was rotated for 400Krevs. There was no issue with hole cleaning observed. Possible reasons for low ROP are insufficient WOB, downhole vibrations that cause inefficient drilling and 4-1 cutting structure of T41 was not aggressive enough for a given formation. After reaching section TD the bit was pulled out to surface and graded as 1 1 NO A F 1 NO TD, whereas bit engineer graded it as 1 1 WT A E I NO TD. The visual inspection of the subject bit revealed no major damage on the bit. Cutting structure of T41 exhibited normal wear and came out to surface with still effective bearings, though, normally, drilling under continues vibrations significantly reduce bearing life of roller cone bits. Subject T41 is still in good condition and can be considered for re-run. Considering all the above mentioned facts, NOV Downhole recommends using Milled Tooth bits of IADC in the similar application, with apply of sufficient WOB (20-25t), which will help to achieved higher ROP, and packed hole BHA assembly to avoid hole deviation. In order to create a room for further improvement drilling of 26 hole in similar application, NOV Downhole would like to recommend usage of its shock tools which dampens axial vibrations (bouncing) of drilling string and thus prolong the life of BHA components and improve drilling efficiency. DATE: _2 Mar 2012_ Rig Manager: Drilling Supervisor:

5 RUN: CUSTOMER: BIT TYPE: 1 KNOC Fergana Operating Company T41 BIT RUN REPORT WELL NAME: CP-Ex1 SERIAL NUMBER: D RIG: XDEC6/ZJ70 SIZE(Inches): 26 RESULTS & CONCLUSION Subject T41 has accomplished set objectives Possible reasons of Low ROP were insufficient WOB, downhole vibrations and less aggressive cutting structure Cutting structure has exhibited normal wear T41 was rotated for 400Krevs and came out to surface with effective bearing, although it was used under continues downhole vibrations T41 came out to surface in good condition and can be considered for re-run RECOMMEN- DATION Use of Milled Tooth bit with 1 1 cutting structure for 26 hole size drilling in Chust pap field Use of Roller Cone bits with sealed roller bearing to extended bearing life Drill with higher WOB in the range 20 25t to improve ROP Use of packed hole BHA assembly to avoid hole deviation Use NOV Downhole shock tools to dampen axial vibrations (bouncing) thus prolong life of BHA components and improve drilling efficiency Note: Information about the NOV Downhole Shock tools can be provided upon request. DATE: _2 Mar 2012_ Rig Manager: Drilling Supervisor:

6 RUN: 2 BIT TYPE: T13 SERIAL NUMBER: D SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 1 WT A E In NO BHA RIG GRADE: 1 1 NO A E I NO PR RE-RUNNABLE: YES DRILLED OUT SHOE: YES REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 508 Meters TYPE: WBM NOZZ: 3x20/32, 18/32 CJ DEPTH OUT: 830 Meters MW: PPG TFA: 1.18 Sq. In. DRILLED: 322 Meters PV/YP: 14/21 Cp/Pa FLOW: 900 GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: Hrs BIT HHP: 292 TOTAL ROP: - m/hr HSI: 1.22 Good EFFECTIVE ROP: 4.4 m/hr IF: 1,170 Lbs WOB: Tonne NOZ.VEL: 247 Ft/seg RPM: RPM D.H.M. RPM: - RPM TORQUE: Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 496 KRevs ANG. IN: Meters BHA 1: 17 1/2 RC Bit / Sub / 1 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / x-o / 9 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; BHA 2: 17 ½ RC Bit / Junk Basket / x-o / Sub / 2 x 9 DC / 17 ½ S. Stab / 1 x 9 DC / 17 ½ S. Stab. / 1 x 9 DC / x-o / MWD / 1 x 8 NMDC / 13 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; AZIM IN: 38 ANG. OUT: 0.7 AZIM OUT: N/A DLS: 830 Meters LITHOLOGIES: Claystones-90%, Siltstone 10% with little 2-4 mm Gravel stringers

7 RUN: 2 BIT TYPE: T13 SERIAL NUMBER: D SIZE(Inches): 17 1/2 COMMENTS 17 ½ T13 is a milled tooth bits (IADC 1-3-5) designed for soft formations with low compressive strength and high drillability. It was run twice in CP-Ex1 well. The objective for the first run was to drill out the casing shoe and continue drilling 17 ½ vertical section (depending on ROP) with Rotary BHA (BHA 1) assembly. T13 drilled 322 meters of formation (Interval of meters) through layers of Claystone and Siltstone with rare Gravel stringers of 2-4 mm size. Overall no issues with hole cleaning were observed, except 5-6t overpulls at the of 646meters, due to wellbore instability which was cured after increase of Mud Weight. Continues downhole vibrations were observed while drilling given interval, where trial of various drilling parameters did not result changes in performance. Possibly, the cutting structure of T13 did not match formation that was drilled. On the subject run the bit was rotated for 459,273 revolutions and at 830 meters depth was pulled to surface due to undesirable ROP, where the decision was made to replace Milled Tooth bit with PDC. T13 achieved av. ROP of 4.4 m/hr. On surface T13 was dull graded as 1 1 WT A E I NO BHA, where the bit engineer s grading was the same. The cutting structure exhibited no significant wear and the bit came out to surface with effective bearings. The bit was in re-run condition and could be considered for another run if there was a need for it. At the depth of 1942mm subject T13 was run again to clean out the junk in the hole possibly left from previously run T43C bit. T13 was RIH with rotary BHA (BHA 2 with Junk basket) assembly, which was pulled to surface at 1948m to change BHA and replace milled tooth bit to PDC. Bit drilled 6 meters in the interval of m through layers of Claystone, Sandstone and minor stringers of Conglomerate accumulating av. ROP of 0.86 m/hr. In the subject run the bit was rotated for 36,367 revolutions. Drilling parameters used were as follows: WOB 8-20t; RPM ; Flow Rate 845 gpm; Rotary Torque 3-5 kft x Lbs, SPP-3000 PSI & Mud Weight PPG. The TFA used was 1.18 sq. inch (nozzle conf: 1 x 18CJ + 3 x 20/32),

8 RUN: 2 BIT TYPE: T13 SERIAL NUMBER: D SIZE(Inches): 17 1/2 COMMENTS CONTINUE where HSI achieved was On surface the T13 was graded as 1-1-WT-A-E-I-NO-PR, whereas the bit engineer graded it as 1-1-WT- A-E-I-NO-BHA. The cutting exhibited no wear and the bit came out to surface with effective bearings. 1.2 kg of small metal pieces and 6 middle metal pieces were retrieved from junk basket. Considering above mentioned facts, T13 accomplished all set objectives and in two run was rotated for 495,640 revolutions. It is still in re-run condition. NOV Downhole recommends considering particular bit type for upcoming wells as multi-purpose option. Option for drilling soft formations and drill out / clean out runs. RESULTS & CONCLUSION T13 was used twice on CP-Ex1 well T13 accomplished all set objectives After both runs the bit came out in re-run condition RECOMMEN- DATION T13 is recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs.

9 RUN: 1 BIT TYPE: T13 SERIAL NUMBER: D SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 2 BT N/G E In CT/WT PR RIG GRADE: RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 1531 Meters TYPE: WBM NOZZ: 3x20/32, 18/32 CJ DEPTH OUT: 1573 Meters MW: PPG TFA: 1.18 Sq. In. DRILLED: 42 Meters PV/YP: 14/21 Cp/Pa FLOW: 835 GPM TOTAL HRS: - Hrs DP: 2300 PSI ON BTM HOURS: 35 Hrs BIT HHP: 232 TOTAL ROP: - m/hr HSI: 0.96 Good EFFECTIVE ROP: 1.2 m/hr IF: 1,170 Lbs WOB: Tons NOZ.VEL: 247 Ft/seg RPM: RPM D.H.M. RPM: - RPM TORQUE: 3-4 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: KRevs ANG. IN: Meters 17 ½ RC Bit / Sub / 2 x 9 DC / 17 ½ S. Stab / 1 x 9 DC / 17 ½ S. Stab. / 1 x 9 DC / x-o / MWD / 1 x 8 NMDC / 7 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; AZIM IN: 155,8 ANG. OUT: 1.8 AZIM OUT: 166,1 DLS: 1573 Meters LITHOLOGIES: Claystones-55%, Sandstone 20% andgravel - 25%

10 RUN: 1 BIT TYPE: T13 SERIAL NUMBER: D SIZE(Inches): 17 1/2

11 RUN: 1 BIT TYPE: T13 SERIAL NUMBER: D SIZE(Inches): 17 1/2 The objective for new 17.5" T13 was to ream approximately 19 meters of undergauge hole section (because of previous TFR519S-A3 was pulled out to surface from the depth of 1531m with significant gauge wear) and then continue drilling 17 ½ vertical section (depending on ROP). COMMENTS During RIH tight spots (4-5t) were observed at the depth of 1520m. Probably undergauge hole section started from this depth. At the beginning of reaming WOB has not increased more than 4t to avoid a possible of sidetracking. After 4m of reaming, WOB increased to 7-8t. At the depth of 1526m axial vibrations (bit bouncing) were observed. WOB has increased to 10-12t to stop vibrations. TQ increased significantly up to 20 klb*ft and TDS stopped rotation because of TQ limitation has sated on 15 klb*ft. Have reached the bottom (1531, 69m) after several tries. TQ spikes up to 20 klb*ft were observed again and were fluctuating from 0-20 klb*ft. There was a possible that lost cutters of previous PDC bitwere on the bottom affects TQ spikes. Decreased FR from 54 to 46 l/s to reduce fluctuating of those cutters and push them into the hole wall. After finishing the reaming of under gauge hole section, start drilling. At the beginning of drilling axial vibrations were observed several times, possible reasons for this were formationwhich containedgravel reached 25%. T13 drilled 42 meters of formation (Interval of meters) through layers of Claystone, Sandstone and Gravel,with average ROP of 1.2m/hrs. Continues downhole vibrations were observed while drilling given interval, where trial of various drilling parameters did not result changes in performance. Due to the cutting structure of T13 wasnot suitable for this kind of formation. Inasmuch as 17 ½ T13 is a milled tooth bits (IADC 1-3-5) designed for soft formations with low compressive strength and high drillability. On the subject run the bit was rotated for 300,426 revolutions and at 1573 meters depth was pulled to surface due to low ROP. On the surface T13 was dull graded as 1-2-BT-N/G-E-I-CT/WT-PR. The major dull characteristic for the cutting structure was broken and chipped teeth on the nose and gauge of the bit which indicates on axial vibration. The wear pattern was not similar on each cone. Cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. RESULTS & CONCLUSION T13 accomplished all set objectives After reaming undergauge hole section and drilling through hard formation such as gravel the bit came out in re-run condition RECOMMEN- DATION T13 is recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs.

12 RUN: 2 BIT TYPE: T41C SERIAL NUMBER: D SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 2 BT N/G E 1/8 WT/CT/OC/TR PR RIG GRADE: RE-RUNNABLE: NO DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 1573 Meters TYPE: WBM NOZZ: 3x20/32, 18/32 CJ DEPTH OUT: 1600 Meters MW: PPG TFA: 1.17 Sq. In. DRILLED: 27 Meters PV/YP: 14/21 Cp/Pa FLOW: 856 GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: 33,75 Hrs BIT HHP: 255 TOTAL ROP: - m/hr HSI: 1.04 Good EFFECTIVE ROP: 0,8 m/hr IF: 1071 Lbs WOB: Tons NOZ.VEL: 235 Ft/sec RPM: RPM D.H.M. RPM: - RPM TORQUE: 3,5 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 403 KRevs ANG. IN: Meters BHA 1: 17 ½ RC Bit / Junk Basket / x-o / Sub / 2 x 9 DC / 17 ½ S. Stab / 1 x 9 DC / 17 ½ S. Stab. / 1 x 9 DC / x-o / MWD / 1 x 8 NMDC / 7 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; BHA 2: 17 1/2 RC Bit / Sub / 2 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / x-o / MWD / 1 x 8 NMDC / 7 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; AZIM IN: 166,1 ANG. OUT: 1.5 AZIM OUT: 177,1 DLS: 1580 Meters LITHOLOGIES: Claystones, Sandstone, Gravel, Conglomerate

13 RUN: 2 BIT TYPE: T41C SERIAL NUMBER: D SIZE(Inches): 17 1/2

14 RUN: 2 BIT TYPE: T41C SERIAL NUMBER: D SIZE(Inches): 17 1/2 COMMENTS T41Cbit was run twice in CP-Ex1 well. The objective for the first run was to clean out the junk in the hole possibly left from previously run T13 bit. T41C was RIH with rotary BHA (BHA 1 with Junk basket), which was pulled to surface at 1600m to change BHA and replace insert bit to PDC. Bit drilled 27 meters in the interval of m through layers of Claystone, Sandstone, Gravel and Conglomerate accumulating av. ROP of 0.8 m/hr. In the subject run the bit was rotated for 192,350 revolutions. On surface the T41C was graded as 1-1-WT-A-E-I-TR-PR. The cutting exhibited no wear and the bit came out to surface with effective bearings. At the depth of 1818m subject bit was run againwith rotary BHA (BHA 2) to continue drilling, due to formation changefrom medium to hard (conglomerate-25%), during drilling with previous TFR619S-A3 which came to surface 3/16 undergauge. On the subject run T41C drilled 20 meters of formation (Interval of meters) through layers of Claystone,Sandstone andconglomerate 25-30%, where continuesaxial vibrations were observed. Multiple attempts to vary the drilling parameters were unsuccessful.wob was limited (not more than 18t) due to weight below jar was 24t. The decision was made to change to less aggressive insert bit (IADC 435) and add 6 joints of DC to BHA. On the subject run the bit was rotated for 403,000 revolutions and at 1838 meters depth was pulled to surface due to low ROP. On surface T41C was dull graded as 1-2-BT-N/G-E-1/8-WT/CT/OC/TR-PR. The major dull characteristic for the cutting structure was broken and chipped teeth on the nose and gauge of the bit which indicates on axial vibration. The wear pattern was not similar on each cone. Cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. T41C has not accomplished all set objectives due to low ROP and came out to surface in non re-run condition. Since17 ½ T41C is an insert bit (IADC 4-1-5) designed for soft formations with low compressive strength and high drillability, NOV DOWNHOLE recommends to consider T41C for using in the upcoming wells for drilling soft formation and drill out / clean out runs. RESULTS & CONCLUSION T41C was used twice on CP-Ex1 well T41Cwas not accomplished all set objectives Reasons for low ROP are: Insufficient WOB due to not enough DC in BHA; Downhole vibrations that cause inefficient drilling; Formation has changed;content of conglomerate has reached 30%; T41C came out to surface 1/8 undergauge, thus cannot be considered for re-run RECOMMEN- DATION Drilling with more WOB in the range 22-26t during drilling hard formation such as conglomerate to improve ROP; Assembling BHA with enough DC to have a possible apply more WOB. T41 is recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs.

15 RUN: 1 BIT TYPE: T43C SERIAL NUMBER: D SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 3 5 BT M/G E/F/E 1/8 JD/CT HR RIG GRADE: - RE-RUNNABLE: NO DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 1838 Meters TYPE: WBM NOZZ: 1x18; 1x20; 2x22 DEPTH OUT: 1942 Meters MW: 9.8 PPG TFA: 1.36 Sq. In. DRILLED: 104 Meters PV/YP: 12/21 Cp/Pa FLOW: GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: 110 Hrs BIT HHP: TOTAL ROP: - m/hr HSI: ,82 Good EFFECTIVE ROP: 1.63 m/hr IF: Lbs WOB: 7-24 Tonne NOZ.VEL: Ft/sec RPM: RPM D.H.M. RPM: - RPM TORQUE: 2-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: Revs ANG. IN: Meters BHA:17 1/2 RC Bit / F/S w/float / 1 x 9 DC /1 x 9 DC/ 17 1/2 S. Stab / 1 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / x-o / MWD /8" NMDC /13 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP. AZIM IN: ANG. OUT: 1.3 AZIM OUT: Meters LITHOLOGIES: Claystones-75%, Sandstone 20%,conglomerate-5%.

16 RUN: 1 BIT TYPE: T43C SERIAL NUMBER: D SIZE(Inches): 17 1/2 COMMENTS The objective for the above bit was to drill the vertical section from the depth 1838m.Totally this bit drilled 104 meters of formation through layers of Claystone and Sandstone andconglomerates with average ROP 1.03 m/h. Overall there were no issue with hole cleaning were observed. T43C is an insert bit (IADC 4-3-5) designed for soft formations with low compressive strength and high drillability. Possible reasons oflow ROP were vibrations which affectdrilling efficiencyand aggressive cutting structure for drilling of such formations. In the interval m torque spikes up to 10 kft/lb and vibrations were observed. When the bit reached the depth of 1938m continues torque spikes and vibrations were observed till the depth of 1942m. The bit was rotated in the hole for 734,741 revs. Normally while rotating the bit in hole for extensive period of time under continues vibrations the service life of bearings significantly reduces. Thus it wasimportant to pull the drill string out to surface and check the condition of the bit. On the surface the bit was graded as: 3-5-BT-M/G E/F/E 1/8 - JD/CT - HR. The visual inspection of the bit revealed that the cutting structure mainly exhibited chipping and broken in the middle and gauge rows and bit came outto surface 1/8 undergauge. Normally, chipped and broken inserts occur due to impacts caused either severe continues vibrations or junk in the hole. It seems like that both of above mentioned scenarios can be fit to our case. Drilling with T43C on the subject well was performed almost under continues vibrations and the amount of junk retrieved (1.2 kg of small metal pieces and 6 middle metal pieces) from the junk basket on the following run with T13 bit justifies possibility of junk damage. The reason why the bit came out to surface 1/8 undergauge, can be lateral vibration. If you refer to dull pictures of the bit you may see thatthe shirttail on one cone was worn more than the other two.

17 RUN: 1 BIT TYPE: T43C SERIAL NUMBER: D SIZE(Inches): 17 1/2 COMMENTS CONTINUE This shows the bit was not drilling about its centerline, but orbiting off center - one shirttail was contacting the formation more than the other two. Usually, this causes bearings failure on that cone if the bit is run long enough. Basically, on the subject run one of the cones of the bit failed. Considering above mentioned facts and observations, subject 17 ½ T43 has showed good performance in terms of bearing reliability. Though, in order to improve ROP in drilling similar applications, the use of NOV Downhole s large diameter roller cone bits of Titan series with IADC 515 or 535 can be considered as better option. For further performance enhancement in 17 ½ hole size drilling, we also would like to recommend use of NOV DOWNHOLE shock tools to reduce ratio of the axial vibrations while drilling, which will extend the service life of BHA components and improve the drilling efficiency. RESULTS & CONCLUSION T43С has not accomplished set objectives T43С showed good performance in terms of bearing reliability Cutting structure of T43 has suffered from impact damage caused by vibrations and junk in the hole T43С came out to surface 1/8 undergauge due to lateral vibrations T43С is not in re-run condition RECOMMEN- DATION Use of NOV Downhole s large diameter roller cone bits of Titan series with IADC 515 or 535 for drilling similar formation Use of NOV DOWNHOLE shock tools to reduce ratio of the axial vibrations while drilling which will extend the service life of BHA components and improve the drilling efficiency. Note: The information about NOV DOWNHOLE shock tools can be provided upon request.

18 RUN: 2 BIT TYPE: TFR519S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 3 8 WT S/G X 4 7/8 BT/CT PR RIG GRADE: 5 8 WT G/S X 4 7/8 BT/LT/HC PR RE-RUNNABLE: NO DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 830 Meters TYPE: WBM NOZZ: 5 x 16/32 DEPTH OUT: 1531 Meters MW: PPG TFA: Sq. In. DRILLED: 701 Meters PV/YP: 20/19 Cp/Pa FLOW: 850 GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: Hrs BIT HHP: 357 TOTAL ROP: - m/hr HSI: 1.48 Good EFFECTIVE ROP: 4.6 m/hr IF: 1,270 Lbs WOB: 2-9 Tonne NOZ.VEL: 278 Ft/seg RPM: RPM D.H.M. RPM: 145- RPM 155 TORQUE: Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: Meters BHA 1: 17 1/2 PDC Bit / x-o / DHM / x-o / Sub / 1 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / 17 1/2 S. Stab / 1 x 9 DC / x-o / MWD x-o / 1 x 8 NMDC / 9 x 8 DC / x-o / 15 x 5 ½ HWDP / 5 ½ DP; AZIM IN: - ANG. OUT: 1.5 AZIM OUT: DLS: 1460 Meters LITHOLOGIES: Claystones-80%, Siltstone 15% and Sandstone -5%

19 RUN: 2 BIT TYPE: TFR519S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2

20 RUN: 2 BIT TYPE: TFR519S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2 COMMENTS The objective for a new TFR519S-A6 was drill 17 ½ section from the depth of 830 m till section TD at 3000m. The subject bit drilled 701 m in the interval of m in hrs through layers of Claystone, Sandstone, and Siltstones with minor layers of gravel of 2-4 mm size and towards the end of the run 20-25% of conglomerates. PDC in the average achieved ROP of 4.59m/h. In the subject well the bit was ran twice, where the reason for the first pull out (at the depth of 1461 m) was due to hours on motor (Dull grade: 1-1-WT-A-X-I-CT-DMF) and the second one was ( at the depth of 1531m) due to low penetration rate. Approximately, till the depth of 1517 m TFR519S showed good performance, where the ROP ranged between 4 7 m/hr., though it could drill even faster with apply of more WOB. The WOB was controlled due to torque limit on downhole motor. In the interval of m the ROP suddenly dropped down to 1 2 m /hr and top drive stalling was observed. Thus after reaching the depth of 1531 m the decision was made to pull out to surface. On surface the bit was graded as 3 8 WT G/S X 4 7/8 BT/CT PR. The cutting structure and the bit body exhibited sever wear (refer to dull pictures). The bit came out 4 7/8 inch undergauge. In the inner raw of the cutting structure has suffered less compare to outer raw though the traces of chipped and broken cutter could be seen. The very possible reason for such kind of wear can be hard interbedded formations (2-4 mm size gravel & 20-25% of conglomerates) and downhole vibrations. TFR519S-A6 is 5 blades and 19 mm cutters aggressive steel body bit which is not suitable for drilling in hard formations. Due to its aggressive nature while drilling through hard formations the cutting structure eventually gets damaged, which affects the stability of the bit and causes downhole vibrations. TFR519S-A6 is hardfaced steel body bit and when it loses gauge cutters the blades get exposed to wellbore and under continues contact (friction) with the wellbore, we witness such kind excessive wear on the bit body. Considering above mentioned facts, TFR519S-A6 has showed good performance though was pulled out to surface in non rerun condition. NOV Downhole recommends to consider running particular type PDC in the upper intervals of 17 ½ section of Chust-Pap field, where the formation does not contain gravels and conglomerates. It is also strongly recommended closely watch cuttings on the shakers while drilling with PDC bits that are fitted with 19mm cutters and react immediately to any formation change in order to be able to save the bit from damage in hard formation. RESULTS & CONCLUSION TFR519S-A6 has not accomplished set objectives, but showed impressive performance. TFR519S-A6 is capable to achieve ROP 10-15m/h in the similar applications if recommended drilling parameters are applied TFR519S-A6 came out to surface 4 7/8 undergauge and cannot be considered for re-run Excessive gauge wear was possibly caused by hard formation (2-4 mm size gravel & 20-25% of conglomerates) and downhole vibrations. RECOMMEN- DATION NOV Downhole recommends: Consider running TFR519S-A6 type PDCs for vertical applications with soft formations Closely watch cuttings on the shakers and react immediately to any formation change, in order to able to save the bit from damage in hard formations

21 RUN: 2 BIT TYPE: TFR619S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 3 BT S/G X 3 CT/WT PR RIG GRADE: 3-5-BT-T/S/G-X-3/16-CT/LT/WT-PR RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 1600 Meters TYPE: WBM NOZZ: 9x12/32 DEPTH OUT: 1818 Meters MW: 9.8 PPG TFA: 0.99 Sq. In. DRILLED: 218 Meters PV/YP: 12/21 Cp/Pa FLOW: 856 GPM TOTAL HRS: - Hrs PSI DP: 2950 ON BTM HOURS: 69 Hrs BIT HHP: TOTAL ROP: - m/hr HSI: Good EFFECTIVE ROP: 7.41 m/hr IF: Lbs WOB: 3-14 Tonne NOZ.VEL: Ft/seg RPM: RPM D.H.M. RPM: - RPM TORQUE: 4-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - Revs ANG. IN: 1.5 AZIM IN: Meters BHA:17 1/2" PDC/ F/S w/float/ 1 x 9 DC /17 1/2" S.Stab/1 x 9 DC / 17 1/2" S.Stab/ 1 x 9 DC / x-o / MWD /8" NMDC /7 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 15 x 5 ½ HWDP. 1 ANG. OUT: 2.7 AZIM OUT: Meters LITHOLOGIES: Claystones, Sandstone, Siltstone,Conglomerate.

22 RUN: 2 BIT TYPE: TFR619S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2

23 RUN: 2 BIT TYPE: TFR619S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2 COMMENTS The objective for a new TFR619S-A3 was drill 17 ½ vertical section from the depth 1600m till planned section TD at 3000m. The subject PDC after drilling 218 m of formation through layers of mainly Claystones interbedded with stringers of sandstone and siltstone and 25% of conglomerate layers toward the end of the run. The average ROP achieved for the run was 3.16m/h. The HSI was within the recommended range above 1. On CP-Ex1 well the TFR619S-A3 was run twice. On the first run the PDC showed very good ROP in the range 4 7 m/r drilling through relatively soft layers of claystone interbedded with stringers of sandstone and siltstone. The bit had capabilities to perform at higher penetration if more WOB (10-15t) would have been applied during the run, but due to hole deviation problems it was not done. There were no issues with hole condition were observed. At the depth of 1809 m the decision was made to pull the string out to surface due to MWD failure. On surface the bit was graded as 1-1-WT-A-X-I-NO-DTF. The visual inspection of the bit revealed that the cutting structure has exhibited normal wear and was in re-run condition. Thus after replacing MWD the decision was run back in hole with the same TFR619S-A3 bit. On the second run, while RIH operation in the interval of m periodical WOB spikes were observed in the range of 5-7 t, due to tight holes, which obliged drilling team to ream through this interval. The formation was changed. The presence of conglomerate in the formation increased up to 25%, which was the main reason for significant ROP reduction. Several attempts on changing of drilling parameters to enhance the penetration rate were unsuccessful. Thus at the depth of 1818m the decision was made to pull the string out to check the bit and BHA components. On the surface the bit was graded as 1-3-BT-S/G-X-3-CT/WT-PR. The visual inspection of the bit revealed that the cutting structure exhibited sever impact damage mainly at the shoulder and gauge. It had numerous cutters broken and chipped. The hardfacing on the gauge pad of blades 1, 4 and 6 was missing as well. Looking at the wear pattern of the bit we can assume that such wear occurred due to repeated impacts which caused PDC cutters to chip and break. This also could cause small cracks in the hardfacing that grow at the contact of the hardfacing and the bit body metal. The repeated impacts are most likely from the bit whirl caused by low depth of cut. This is usually can be seen on long runs in hard rocks, such as cemented conglomerates. Considering, the ROP was low the bit was rotated in the hole for extended period of time (20.5hrs), which resulted such kind of severe wear of cutting structure. Taking into account all the above made comments and observations, the TFR619S-A3 has failed to achieve set objectives due to geological factors. Because of the exploratory nature of CP-Ex1 well, nobody expected to meet such high percentage (25%) of hard conglomerates in the drilled interval. Currently, PDC is non re-run condition and cannot be considered for further use.

24 RUN: 2 BIT TYPE: TFR619S-A3 SERIAL NUMBER: E SIZE(Inches): 17 1/2 COMMENTS CONTINUE NOV Downhole recommends the use of particular type PDC bits in the upper intervals of 17 ½ section of Chust-Pap field, where the formation does not contain any gravels and conglomerates. It is also strongly recommended to watch closely the cuttings on the shakers while drilling with PDC bits that are fitted with 19mm cutters and react immediately to any formation change in order to be able to save the bit from damage in hard formation. RESULTS & CONCLUSION TFR619S-A3 has not accomplished set objectives, due to geological factors. TFR619S-A3 is capable to achieve ROP 10-15m/h in the similar applications if recommended drilling parameters are applied TFR619S-A3 came out to surface 3/16 undergauge TFR619S-A3 exhibited severe damage on cutting structure and had hardfacing on the gauge pad of blades 1, 4 & 6 missing due to repeated impacts caused by bit whirl (lateral vibrations) NOV Downhole recommends: RECOMMEN- DATION Consider running TFR619S-A3 type PDCs for vertical applications with soft formations Closely watch cuttings on the shakers and react immediately to any formation change, in order to able to save the bit from damage in hard formations

25 RUN: 2 BIT TYPE: TFR619S-A6 SERIAL NUMBER: E SIZE(Inches): 17 ½ INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 2 BT A X In CT/HC/BU TD RIG GRADE: RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 2451 Meters TYPE: WBM NOZZ: 1x15/32; 2x16/32; 3x18/32 DEPTH OUT: 2945 Meters MW: 10.5 PPG TFA: 1.31 Sq. In. DRILLED: 494 Meters PV/YP: 28/23 Cp/lb/100sf FLOW: GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: Hrs BIT HHP: TOTAL ROP: - m/hr HSI: Satisfactory EFFECTIVE ROP: 1.94 m/hr IF: Lbs WOB: 4-11 Tons NOZ.VEL: Ft/sec RPM: RPM D.H.M. RPM: - RPM TORQUE: 5-9 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: Meters BHA:17 1/2" PDC / Floatsubw/float / 3x9" DC / 17 1/2" S.Stab / 1x9" DC/ x-o/ MWD / 1x 8"NMDC / 6x8" DC / 1x8" Jar / 2x8" DC / x-o / 15x5 ½ HWDP / 5 ½ DP; AZIM IN: 156 ANG. OUT: 2.78 AZIM OUT: 168 DLS: 2931 Meters LITHOLOGIES: Claystone, siltstone, sandstone.

26 RUN: 2 BIT TYPE: TFR619S-A6 SERIAL NUMBER: E SIZE(Inches): 17 ½

27 RUN: 2 BIT TYPE: TFR619S-A6 SERIAL NUMBER: E SIZE(Inches): 17 ½

28 RUN: 2 BIT TYPE: TFR619S-A6 SERIAL NUMBER: E SIZE(Inches): 17 ½ COMMENTS The objective for new TFR619S-A6 was to drill remaining part of 17 ½ vertical section from the depth of 2451m till section TD. Totally the bit drilled 494 meters of formation in the interval meters through interbedded layers of Claystone, Siltstone andsandstone, accumulating av. ROP of 1.94m/hr. The subject bit was twice pulled to surface, while drilling above mentioned interval. In the first run the bit drilled 230 meters of formation with av. ROP of 3 m/hr in the interval of meters. The reason for pull out was an accident due to wash out 8 DC part of BHA lost in hole. In the beginning of the run the ROP was ranging 5-6m/hr with WOB applied 9-10 tones, which gradually decreased down to 2 m/hr as drilling proceeded. The causes of such reduction in penetration rate possibly were poor bit cleaning and inability to apply 10-15t of WOB (due to hole deviation problem). On surface the bit was graded as 1-1-BT-N/S-X-I-CT/HC/BU-LIH. The cutting structure exhibited broken cutters with slight chipping, heat checking. The bit was in good re-run condition thus was run back in hole to continue drilling. In the second run TFR619S-A6 drilled 264 meters of formation in the interval of meters (section TD), through interbedded layers of Claystone, Siltstone and Sandstone accumulating average ROP of 1.58m/hrs. Continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. Problems with hole deviation continued. On surface the bit was graded as 1-2-BT-A-X-I-CT/HC/BU-TD. The major dull characteristic for the cutting structure was broken and chipped cutters on the nose, shoulder and gaugeof the bit and heat checking. The wear pattern was not similar on each blade. This kind of wear normally occurs due to lateral vibration while reaming or drilling operations. Heat checking on worn cutters and broken /chipped cutters at the gauge of every blade is indication of torsional vibration. Two broken cutters on the inner raw of cutting structure are indication of axial vibration. Heat checking is indicationof insufficient bit cleaning. The bit also came out to surface balled up. Considering above made observations we can conclude that cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. The possible causes of bit balling can be insufficient bit cleaning (due to large TFA and low HSI). The TFR619S-A6 has aggressive cutting structure (6 blades 19mm) fitted with NOV Downhole sraptor cutters that are designed for maximized abrasion resistant and heat tolerant. Overall the TFR619S-A6 came out to surface in re-run condition and had capabilities to continue drilling with higher ROP if not the obstacles (poor bit cleaning andinsufficient WOB due to hole deviation problems) limiting its performance. For future projects NOV Downhole recommends to consider TFR619S-A6 as one of good options for drilling 17 ½ section with similar application. Good ROP and Durability (longer service life) performance can be achieved if the recommended drilling parameters (WOB in the range of 10-15t and HSI above 1) are applied. RESULTS & CONCLUSION Subject TFR619S-A6 hasaccomplished set objectives; Reasons for low ROP are: Insufficient, restricted WOB due to inclination problem; Downhole vibrations that cause inefficient drilling; Insufficient bit cleaning (due to large TFA and low HSI); TFR619S-A6 came out to surface in a good, re-run condition. RECOMMEN- DATION Apply of recommended drilling parameters may improve av. ROP and extend service life of the bit. RPM when encountering conglomerate or other hard formations should below 100 to maximize cutters life and ensure full formation penetration; Drilling with more WOB in the range 10-15t during drilling hard formation to improve ROP; Hard formations require high WOB and low RPM to allow bits to penetrate and shear the formation; Apply HSI above 1 to allow clean and cool cutters of the bit.

29 RUN: 2 BIT TYPE: TFF716S-A2 SERIAL NUMBER: E SIZE(Inches): 17 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 3 BT S/G X In CT/WT/BU PR RIG GRADE: RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 1948 Meters TYPE: WBM NOZZ: 3x15/32; 4x16/32 DEPTH OUT: 2451 Meters MW: PPG TFA: Sq. In. DRILLED: 503 Meters PV/YP: 30/18 Cp/lb/100sf FLOW: 794 GPM TOTAL HRS: - Hrs DP: PSI ON BTM HOURS: Hrs BIT HHP: TOTAL ROP: - m/hr HSI: Satisfactory EFFECTIVE ROP: 2.17 m/hr IF: Lbs WOB: 7-15 Tons NOZ.VEL: 196 Ft/sec RPM: RPM D.H.M. RPM: - RPM TORQUE: 3-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: Meters BHA:17 1/2" PDCBit / Floatsubw/float / 2x9" DC / 17 1/2" S.Stab / 1x9" DC / 17 1/2" S.Stab / 1x9" DC / x-o / MWD / 1x 8"NMDC / 7x8" DC / 1x8" Jar / 2x8" DC / x-o / 15x5 ½ HWDP / 5 ½ DP; AZIM IN: 157 ANG. OUT: 2.68 AZIM OUT: 156 DLS: 2451 Meters LITHOLOGIES: Claystone, sandstone, siltstone, conglomerate.

30 RUN: 2 BIT TYPE: TFF716S-A2 SERIAL NUMBER: E SIZE(Inches): 17 1/2

31 RUN: 2 BIT TYPE: TFF716S-A2 SERIAL NUMBER: E SIZE(Inches): 17 1/2

32 RUN: 2 BIT TYPE: TFF716S-A2 SERIAL NUMBER: E SIZE(Inches): 17 1/2 COMMENTS The objective for new TFF716S-A2 was to drill remaining part of 17 ½ vertical section from the depth of 1948m till section TD. Totally the bit drilled 503 meters of formation in the interval meters through interbedded layers of Claystone, Sandstone, Siltstone and Conglomerates accumulating av. ROP of 2.17m/hr. The subject bit was twice pulled to surface, while drilling above mentioned interval. In the first run the bit drilled 202 meters of formation with av. ROP of 2.95 m/hr in the interval of meters. The reason for pull out was rig maintenance. In the beginning of the run the ROP was ranging 5-6m/hr with WOB applied 7 tones, which gradually decreased down to 2 m/hr as drilling proceeded. The causes of such reduction in penetration rate possibly were poor bit cleaning (from the depth of 1978 meters SPP increased up 3200 PSI, probably due to nozzle plugging or balling), hard formations (up 20% of conglomerates layers) and inability to apply 15-20t of WOB (due to hole deviation problem). On surface the bit was graded as 1-1-WT-A-X-I-CT- RIG. The cutting structure mainly exhibited normal wear with slight chipping. The bit was in good re-run condition thus was run back in hole to continue drilling. In the second run TFF716S-A2 drilled 301 meters of formation in the interval of meters through interbedded layers of Claystone, Sandstone, Siltstone and Conglomerates accumulating average ROP of 1.84m/hrs. The reason for pull out was low penetration rate. While RIH to continue drilling, several tight hole intervals ( meters) were observed, which were reamed. Back reaming was also performed while drilling interval m where formation contained 10-20% of Conglomerates. Continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. Problems with hole deviation continued. Towards the end of the run drilling mud losses were also observed. On surface the bit was graded as 1-3-BT-S/G-X-I-CT/WT/BU-PR. The major dull characteristic for the cutting structure was broken and chipped cutters on the gauge and shoulder of the bit. The wear pattern was not similar on each blade. This kind of wear normally occurs due to lateral vibration while reaming or drilling operations. Broken and chipped cutters at the gauge of every blade are indication of torsional vibration. Two chipped cutters on the inner raw of cutting structure are indication of axial vibration. The bit also came out to surface slightly balled up. Considering above made observations we can conclude that cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. The possible causes of bit balling can be insufficient bit cleaning (due to large TFA and low HSI) and hole problems (due to losses occurred towards the end of the run). Another observation that requires recognition is the durability of cutting structure on TFF716S-A2 while drilling through interbedded layers of Claystone, Sandstone and Siltstone with 3-20% layers of hard conglomerate. The TFF716S-A2 has medium set cutting structure (7 blades 16mm) fitted with NOV Downhole s latest DuraForce cutters that are designed for maximized impact toughness. Overall the TFF716S-A2 came out to surface in re-run condition and had capabilities to continue drilling with higher ROP if not the obstacles (Insufficient WOB due to hole deviation problems) limiting its performance. For future projects NOV Downhole recommends to consider particular PDC type as one of the good options for drilling 17 ½ section with similar application. Good ROP and Durability (longer service life) performance can be achieved if the recommended drilling parameters (WOB in the range of 15-20t and HSI above 1) are applied.

33 RUN: 2 BIT TYPE: TFF716S-A2 SERIAL NUMBER: E SIZE(Inches): 17 1/2 RESULTS & CONCLUSION Subject TFF716S-A2 has notaccomplished set objectives; Reasons for low ROP are: Insufficient, restricted WOB due to inclination problem; Downhole vibrations that cause inefficient drilling; High RPM does not allow the cutting structure to penetrate the formation sufficiently, this may lead to vibration; Formation change; especially content of conglomerate has reached 20%; TFF716S-A2came out to surface in not bad condition and can be considered for re-run. RECOMMEN- DATION Apply of recommended drilling parameters may improve av. ROP and extend service life of the bit. RPM when encountering conglomerate or other hard formations should below 100 to maximize cutters life and ensure full formation penetration; Drilling with more WOB in the range 15-20t during drilling hard formation such as conglomerate to improve ROP; Hard formations require high WOB and low RPM to allow bits to penetrate and share the formation. Use of packed hole BHA assembly to avoid hole deviation.

34 RUN: 3 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4 NNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 2 BT G X 1/16 CT/HC HP RIG GRADE: - RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 2949 Meters TYPE: WBM NOZZ: 1x18; 5x15 DEPTH OUT: 3608 Meters MW: 10.9 PPG TFA: Sq. In. DRILLED: Meters PV/YP: 26/25.0 Cp/Pa FLOW: GPM TOTAL HRS: - Hrs PSI DP: 3720 ON BTM HOURS: Hrs BIT HHP: 149 TOTAL ROP: - m/hr HSI: 1.27 Good EFFECTIVE 6.31 m/hr IF: 743 Lbs ROP: WOB: 3-10 Tonne NOZ.VEL: 199 Ft/seg RPM: 50 RPM D.H.M. RPM: RPM TORQUE: 5-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - Revs ANG. IN: 2.4 AZIM IN: Meters BHA1:PDC Bit 12 1/4", DHM,Float sub w/float,12 1/4" ANG. OUT: 0.92 S.Stab,MWD,8"NMDC,12 1/4" S.Stab,8" DCx9,8" Jar,8" DCx2,X/O,X/O,HWDPx18. BHA2:PDC Bit 12 1/4", DHM,Float sub w/float,12 1/4" S.Stab,MWD,8"NMDC,8" DCx9,8" Jar,8" DCx2,X/O,X/O,HWDPx18,DPx192 BHA3:PDC Bit 12 1/4", DHM (adjustable 1 ),Float sub w/float,12 1/4" S.Stab,MWD,8"NMDC,8" DCx9,8" Jar,8" DCx2,X/O,HWDPx18,DPx192 AZIM OUT: Meters LITHOLOGIES: Claystones, Sandstone, Siltstone.

35 RUN: 3 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4

36 RUN: 3 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4 COMMENTS The objective for new DSR616M-A28 was to continue drilling of 12 ¼ section till TD. Totally the bit drilled meters of formation in the interval meters through interbedded layers of Claystone, Sandstone, Siltstone. Accumulating av. ROP was 3.48m/hr. The subject bit was triply run. Forward and backward reaming operations were performed while drilling above mentioned interval, total amount of which was 41.1 hours. In the first run the bit drilled meters of formation with sliding and rotating mode, av. ROP was 3.43 m/hr in the interval of meters.continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. Problems with hole deviation continued. Towards the end of the drillingafter wiper trip several tight spots (up to 10-12t) and TQ spikes (up to 12-13kft*lb)were observed in the interval of 3355m m, which were reamed. Decision was made increase MW from 10.7 to 11ppg. The bitcould not reach the bottom (3404m) due to TQ spikes. Resume drilling after TQ stabilization. And at the depth 3484,88m ROP dropped to 0.79 m/h, due to DHM failure. Decision was made POOH to change DHM. On the surface the bit was graded as: 1-2-BT-G-X-I-CT/HC-DTF. The major dull characteristic for the cutting structure was broken and chipped cutters with heat checking on the gauge of the bit. The reason for broken gauge cutters is excessive reaming. The total reaming time for this run was 12.5 hours.the bit was in good re-run condition thus was run back in hole to continue drilling. In the second run DSR616M-A28 drilled meters of formation in the interval meters. Accumulating average ROP was 4.02 m/hrs. While RIHintervals oftight spots 4-5 t and torque spikes 5-10 kft*lb were observed, which were reamed. At the depth 3516 meters attempt to take survey but no success, MWD failed.

37 RUN: 3 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4 At the depth 3608m decision was made POOH due to MWD failure. During POOHtorque spikes up to 4-15kft*lb were observedin the interval 3573m to 3551m, hard reaming of this interval was performed. On surface the bit was graded as: 1-2-BT-G-X-I-CT/HC-DTF.The total reaming time for this run was hours, overall bit condition was good and it was run back in the hole to continue drilling. Duringthird RIH permanent torque spikes up to 4-15 kft*/lb and tight spots up to 5-8 t were observedin the interval m. After 3559 meters the bit could not reach the bottom (3608m) due to TQ spikes and tight spots.decision was made POOH to replace PDC with milled tooth bit and perform reaming due to hole problems. On the surface the bit was graded as: 1-2-BT-G-X-1/16-CT/HC-HP.The total reaming time for this run was hours.the bit came out 1/16 inchundergauge and cannot be consider for further run. RESULTS &CONCLUSION DSR616M-A28 was used triply on CP-Ex1 well; DSR616M-A28 has not accomplished set objectives; After three runs the bit came out in non- rerun condition; Inasmuch as hole problems, there were performed reaming operations (41.1 hours in total) which caused of damage gauge cutters of the bit. RECOMMENDATION For future projects NOV Downhole recommends to consider particular PDC type as one of the good options for drilling 12 ¼ section with similar application. Use milled tooth bit instead of PDC bit for reaming, to avoidpremature wear of cutting structure of PDC bit.

38 RUN: 2 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 2 4 BT S/G X I CT BHA RIG GRADE: - RE-RUNNABLE: NO DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: Meters TYPE: WBM NOZZ: 1x18; 5x15 DEPTH OUT: 3714 Meters MW: PPG TFA: Sq. In. DRILLED: Meters PV/YP: 36/37.0 Cp/Pa FLOW: GPM TOTAL HRS: - Hrs DP: PSI ON BTM 42 HOURS: Hrs BIT HHP: 170 TOTAL ROP: - m/hr HSI: 1.45 Good EFFECTIVE 3.49 m/hr IF: 834 Lbs ROP: WOB: 3-8 Tonne NOZ.VEL: 202 Ft/seg RPM: RPM D.H.M. RPM: - RPM TORQUE: 5-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - Revs ANG. IN: 0.97 AZIM IN: Meters ANG. OUT: 2.6 BHA1:PDC Bit 12 1/4", DHM,Float sub w/float,12 1/8" S.Stab,MWD,8"NMDC,8" DCx9,8" Jar,8" DCx2,X/O,HWDPx18. AZIM OUT: Meters BHA2:PDC Bit 12 1/4",Float sub w/float,mwd,8"nmdc,12 1/8" S.Stab,,8" DCx9,8" Jar,8" DCx2,X/O,HWDPx12,DPx192 LITHOLOGIES: Claystones, Sandstone, Siltstone.

39 RUN: 2 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4

40 RUN: 2 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4

41 RUN: 2 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A SIZE(Inches): 12 1/4 COMMENTS The objective for new DSR616M-A28 was to continue drilling of 12 ¼ section till TD. Totally above mentioned bit drilled meters of formation in the interval meters through interbedded layers of Claystone, Sandstone, Siltstone. Accumulating av. ROP was 2.79m/hr. The subject bit was run twice.reaming operations were performed while drilling above mentioned interval, total amount of which was hours. First time the bit was RIH with DHM (BHA1).RIH was with reaming. The bit reached the bottom but could not drill due to DHM failure (there was no pressure drop). Decision was made POOH to check DHM. On the surface the bit was graded as: 1-1-CT-S/G-X-I-NO-BHA. The major dull characteristic for the cutting structure was chipped cutters on the gaugeand shoulder of the bit. The reason for chipped gauge / shoulder cutters is excessive reaming. The total reaming time for this run was 6.15 hours.the bit was in good re-run condition thus was run back in hole to continue drilling. Second time DSR616M-A28 was RIH with rotary BHA (BHA2). In the second run the bit drilled meters of formation in the interval meters. Accumulating average ROP was 2.79 m/hrs. Several intervals of tight spots (4-5t) and TQ spikes (5-15 kft*lb) were observed and reamed while drilling above mentioned interval. From the depth 3707m ROP was decreasing 1.9 m/h, 1.2 m/h, 0,8 m/h and WOB restricted (max. 7t) due to hole deviation problems(2.6 ). It was made a decision to POOH and RIH with DHM (with bent housing 1 ). During POOH TQ spikes up to 15kft*lb were observed in the interval m, this interval was reamed. On the surface the bit was graded as: 2-4-BT-S/G-X-I-CT- BHA.The major dull characteristic for the cutting structure was broken and chipped cutters on the shoulder / gauge of the bit. Total reaming time for this run was hours. The bit was run twice, the first run had some broken shoulder/gauge cutters, but was otherwise in excellent condition so was re-run. The reason for broken shoulder/ gauge cutters is excessive reaming. Thus, those broken cutters were the start of the damage on the 2nd run. Whenthe bit has a broken cutter, the cutters next to it, and also the next cutter in the spiral order have to take more loads, and therefore break more easily than normal. RESULTS &CONCLUSION DSR616M-A28 was used twice on CP-Ex1 well; DSR616M-A28 did not accomplished set objectives; After two runs the bit came out in non-rerun condition; The main reason for damaged cutting structure is excessive reaming. When the bit has a broken cutter, the cutters next to it, and also the next cutter in the spiral order have to take more load, and therefore break more easily than normal. RECOMMENDATION NOV Downhole recommends: Consider particular PDC type as one of the good options for drilling 12 ¼ section with similar application. For reaming operations use milled tooth bit instead of PDC bit, to avoidpremature wear of cutting structure of PDC bit.

42 RUN: 1 BIT TYPE: S13G SERIAL NUMBER: D SIZE(Inches): 12 1/4 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 1 A NO E I NO BHA RIG GRADE: - RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 3608 Meters TYPE: WBM NOZZ: 1x20; 2x22 DEPTH OUT: 3608 Meters MW: PPG TFA: 1.05 Sq. In. DRILLED: - Meters PV/YP: 32/30 Cp/Pa FLOW: GPM TOTAL HRS: - Hrs PSI DP: 3200 ON BTM HOURS: - Hrs BIT HHP: 150 TOTAL ROP: - m/hr HSI: 1.28 Good EFFECTIVE ROP: - m/hr IF: 751 Lbs WOB: 0-2 Tonne NOZ.VEL: 198 Ft/sec RPM: RPM D.H.M. RPM: - RPM TORQUE: 4-12 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: Revs ANG. IN: AZIM IN: - Meters BHA:12 1/4 RC Bit / Bit sub w/float / 9 x 8 DC / 8 JAR / 2 x 8 DC / x-o / 18 x 5 HWDP. ANG. OUT: AZIM OUT: - Meters LITHOLOGIES:

43 RUN: 1 BIT TYPE: S13G SERIAL NUMBER: D SIZE(Inches): 12 1/4

44 RUN: 1 BIT TYPE: S13G SERIAL NUMBER: D SIZE(Inches): 12 1/4 COMMENTS The objective for the above bit was to ream the vertical section from the depth 3493m to Totally this bit reamed 116 meters of drilled interval by previous PDC DSR616M-A28. Previous PDC bit could not ream above mentioned interval, due to hole condition was not stable (regular TQ spikes up to 15kft*lb were observed) and it could not pass through this interval. Decision was made to change PDC bit to Milled tooth bit to perform reaming operations.s13g has reamed above mentioned interval successfully. Following which it was pulled to surface. On the surface the bit was graded as: 1-1-NO-A-E-I-NO-BHA. RESULTS &CONCLUSION S13G has accomplished set objectives S13G showed good performance. S13G came out to surface in good condition and can be considered for rerun. RECOMMENDATION S13G is recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs.

45 RUN: 1 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR713D BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 12 1/4 IADC DULL GRADING INNER OUTTER DULL. LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 1 CT G X I BT BHA RIG GRADE: - RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEP. IN: DEP.OUT: 4032 DRILLED: TOTAL HRS: - ON BTM HOURS: TOTAL ROP: - EFFECTIVE ROP: 2.37 WOB:2-12 RPM: 30 D.H.M. RPM: TORQUE:3-15 TOTAL REVs: Meters Meters Meters Hrs Hrs m/hr m/hr Tone RPM RPM Kft/Lbs Revs TYPE: WBM NOZZ:5x14/32, 2x16/32 MW: PPG TFA:1.15Sq. In. PV/YP: 37/39 Cp/Pa FLOW: GPM DP: PSI BIT HHP: 143 HSI:1.21Poor IF:186Lbs NOZ.VEL:122Ft/sec BHA: 12 1/4 PDC Bit / Mud motor (adjustable1 )/Float sub w/float / 12 1/4" S.Stab/ MWD / 8"NMDC / 9 x 8 DC / 1 x 8 Jar /2 x 8 DC /X/O /18 x 5 HWDP/; SURVEY: ANG.IN: 2.64 AZIM IN: ANG.OUT: 2.29 AZIMOUT: 63.5º DLS: 3716 Meters 4013 Meters DEPTH: LITHOLOGIES: Claystone, Siltstone, Sandstone.

46 RUN: 1 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR713D BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 12 1/4

47 RUN: 1 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR713D BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 12 1/4

48 RUN: 1 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR713D BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 12 1/4 COMMENTS Inasmuch as two 12 ¼ DSR616 were in non-rerun conditions due hole problems, new DSR713D was RIH while new ordered bit will arrive to the Wellsite.The objective for new DSR713D was to drill remaining part of 12 ¼ vertical section from the depth 3716m till arriving of new DSF616D-I2. Totally thebit drilled meters of formation in the interval mwith rotating and sliding mode, through interbedded layers of Claystone, Siltstone, Sandstone.Where accumulating av. ROP of 1.42 m/hr. Performed reaming while drilling above mentioned interval wheretq spikes up to15 kft/lb were observed.continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. At the depth 4032m it was attempt to take survey. Withoutsuccess. Probably the battery of the MWD wasdischarged. Decision was made POOH to change DHM, MWD. On the surface the bit was graded as: 1-1-CT-G-X-I-BT-BHA. The major dull characteristic for the cutting structure was slight chipped and broken cutters on the gauge of the bit. The reason for chipped gauge cutters is excessive reaming.total reaming time of this interval was 9 hours. The reason for low ROP is the cutting structure of DSR713D which is not aggressive. DSR713D has 7 blades with 13mm cutters, which requires more WOB to increase ROP in compare with more aggressive DRS616. There was no possible to apply 12-15t of WOB due to hole deviation problems and TQ limitation of DHM. Overall the bit is in good condition and can be consider as rerun. RESULTS &CONCLUSION Subject DSR713D has accomplished set objectives; The reason for low ROP is the cutting structure of DSR713D which is not aggressive. DSR713D has 7 blades with 13mm cutters; DSR713D came out to surface in good condition and can be considered for re-run. RECOMMENDATION DSR713D is recommended to consider for using in the upcoming wells for drilling hard formations. Drilling with more WOB in the range 12-15t to improve ROP;

49 RUN: 2 BIT TYPE: DSF616D-I2 SERIAL NUMBER: A SIZE(Inches): 12 1/4 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 2 BT S/G X In CT/WT/BU TD RIG GRADE: 1 2 BT S/G X I CT/WT/HC/BU PR RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEPTH IN: 4032 Meters TYPE: WBM NOZZ: 5x12 ; 2x16 ; 2x15 DEPTH OUT: 5010 Meters MW: PPG TFA: 1.29 Sq. In. DRILLED: 978 Meters PV/YP: 40/46 Cp/Pa FLOW: 630 GPM TOTAL HRS: - Hrs DP: 3800 PSI ON BTM HOURS: Hrs BIT HHP: 40 TOTAL ROP: - m/hr HSI: 0.34 VERY LOW EFFECTIVE ROP: 1.78 m/hr IF: 358 Lbs WOB: 6-10 Tonne NOZ.VEL: 110 Ft/sec RPM: 50 RPM D.H.M. RPM: 85 RPM TORQUE: 5-9 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: Meters BHA 1: 12 ¼ PDC Bit / DHM (1 bent) / Float sub / 1 x 12 3/16 Stab. / MWD / 1 x 8 NMDC / 9 x 8 DC / 1 x 8 JAR / 2 x 8 DC / x-o / 18 x 5 HWDP / 5 DP; BHA 2: 12 ¼ PDC / DHM (1 bent) / Float sub / 1 x 8 Short DC / 12 3/16 Stab. / MWD / 1 x 8 NMDC / 7 x 8 DC / 1 x 8 JAR / 2x 8 DC / x-o / 12x5 HWDP / 5 x DP LITHOLOGIES: Claystones-75%, Siltstone 23% and Sandstone -2% AZIM IN: 62.9 ANG. OUT: 0.75 AZIM OUT: DLS: 5008 Meters

50 RUN: 2 BIT TYPE: DSF616D-I2 SERIAL NUMBER: A SIZE(Inches): 12 1/4

51 RUN: 2 BIT TYPE: DSF616D-I2 SERIAL NUMBER: A SIZE(Inches): 12 1/4 COMMENTS The objective for new DSF616D-I2 was to finish the remaining part of 12 ¼ section from the depth of 4032m till TD. The bit has showed slow but stable performance. It has accomplished set objective drilling through hard layers of Claystone, Sandstone and Siltstone. Overall, bit achieved av. ROP of 1.78m/h in the interval m. While drilling subject interval the PDC was pulled to surface once (at the depth of 4507 m), due to hours on MWD /DHM, IBOP leakage and hole problems. HSI of 0.34 achieved for the run was way below the recommended range of 2-7. Thus it reflected on ROP, hole and bit cleaning which resulted in long reaming intervals. At the TD the bit was pulled to surface and graded as 1-2-BT-S/G-X-I CT/WT/HC/ BU-TD. The visual inspection of the bit on surface revealed that the cutting structure has mainly suffered from broken and chipped cutters on the shoulder and gauge. Broken/Chipped cutters on PDC bits usually occur due to impact caused by downhole vibrations. Considering the amount of reaming performed while drilling probably the vibrations occurred were lateral. Beside the mentioned wear the cutting structure exhibited normal wear and came to surface balled up. Bit balling is another justification of poor hydraulics applied while drilling subject section. NOV Downhole recommends reduction and adjustment of drilling parameters to preserve the cutting structure of PDC bits while reaming operations. We also recommend considering particular PDC design for upcoming wells with similar application. Subject DSF616D-I2 remained in re-run condition and can be considered for further use. RESULTS & CONCLUSION DSF616D-I2 has accomplished set objective; PDC showed slow but stable performance through hard formations; Cutting structure mainly exhibited chipped and broken cutters on the shoulder and gauge of the bit; PDC came to surface balled up; HSI achieved for subject run was very low; PDC remained in re-run condition. RECOMMEN- DATION DSF616D-I2 is recommend for upcoming wells with similar applications; Reduction of TFA is recommended to improve the HSI, which will lead to higher ROP and better bit and hole cleaning.

52 RUN: 4 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR616M-J1 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 IADC DULL GRADING INNER OUTTER DULL. LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 4 2 WT N/T X I BT/CT/HC DMF RIG GRADE: - RE-RUNNABLE: NO DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEP. IN:5016 DEP.OUT: DRILLED: TOTAL HRS: - ON BTM HOURS: TOTAL ROP: - EFFECTIVE ROP: 1.82 WOB:2-10 RPM:30-60 D.H.M. RPM: TORQUE:4-7 TOTAL REVs: - Meters Meters Meters Hrs Hrs m/hr m/hr Tone RPM RPM Kft/Lbs Revs TYPE: WBM NOZZ: 6x16/32 MW: 16.6 PPG TFA:1.2Sq. In. PV/YP: 37/54.2 Cp/Pa FLOW: GPM DP: PSI BIT HHP: 81 HSI:1.43Good IF:588Lbs NOZ.VEL:137Ft/sec BHA1: 8 1/2 PDC Bit / Mud motor /Float sub w/float / X/O/6 1/4" MWD/6 1/4" NMDC/8 3/8" S.Stab/ 18 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC /X/O /12 x 5 HWDP/; SURVEY: ANG.IN: 0.75 AZIM IN: ANG.OUT: 4.55 AZIMOUT: 154º DLS: 5030 Meters 5551 Meters DEPTH: LITHOLOGIES: Claystone, Siltstone, Sandstone (very hard, dense and compacted), Limestone, Anhydrite,conglomerate

53 RUN: 4 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR616M-J1 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 BHA2: 8 1/2 PDC Bit / Mud motor / Float sub w/float / X/O/6 1/4" pony DC/8 3/8" S.Stab/ 6 1/4" MWD/6 1/4" NMDC/18 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC / X/O / 12 x 5 HWDP/; BHA3: 8 1/2 PDC Bit / Mud motor / Float sub w/float / X/O/ 6 1/4" MWD/6 1/4" NMDC/8 3/8" S.Stab / 1x6 1/4" DC/8 3/8" S.Stab /16 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC / X/O / 12 x 5 HWDP/; BHA 4: 8 1/2 PDC Bit / Mud motor / Float sub w/float / X/O/ 6 1/4" MWD/6 1/4" NMDC/8 3/8" S.Stab / 17 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC / X/O / 12 x 5 HWDP/;

54 RUN: 4 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR616M-J1 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2

55 RUN: 4 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR616M-J1 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 COMMENTS The objective for new DSR616M-J1 was to finish the remaining part of 8 ½ section from the depth of 5016m till TD.Totally thebit drilled meters of formation in the interval m, through interbedded layers of Claystone, Siltstone, Sandstone (conglomeratic compacted sandstone mainly with quartzite),anhydrite, Limestone, accumulating av. ROP of 0.82m/hr. The subject bit was four times pulled to surface, while drilling above mentioned interval. In the first run the bit drilled meters of formation in the interval of meters with av. ROP 1.2 m/hr. At the depth 5167m attempt to take survey but no success, MWD failed, probablybattery of the MWD was discharged. At the depth 5180 m the SPP dropped to 3400 psi. Increased FR to 31 L/sec. SPP go up to 3800 psi. ROP dropped to 0.57 m/h. Check the differential pressure off bottom and on bottom, SPP is the same. Probably DHM was failed. At the depth of it was made a decision to POOH to change DHM and MWD. On the surface the bit was graded as:1-1-wt-a-x-i-no-bha. The total reaming time for thisinterval was 2 hours. The bit was in good condition thus was run back in hole to continue drilling. In the second run the bit drilled meters of formation with sliding and rotating mode, av. ROP was 1.08 m/hr in the interval of meters. WOB was restricted (max. 7 t), due to inclination.attempt to take survey at 5407m - no success, MWD signal was lost. At the depth of 5450DHM was failed. Decision was made POOH to change DHM and MWD. On the surface the bit was graded as:1-1-wt-a-x-i-no-dmf. The total reaming time for this interval was 3.45 hours. The bit was in good re-run condition thus was run back in hole to continue drilling. In the third run the bit drilled 57.9 meters of formation, av. ROP was 0.69 m/hr in the interval of meters. The bit had capabilities to perform at higher penetration if more WOB (10-15t) would have been applied during the run, but due to hole deviation problems it was not done.at the depth 5507 m the SPP dropped from 3800 to 3550 psi and ROP decreased to 0.4m/h. Off bottom and on bottom pressure was the same. Probably DHM failed. Decision was made POOH. On the surface the bit was graded as:1-1-ct-t/s-x-i-wt-dtf. The major dull characteristic for the cutting structure were chipped cutters on taper and shoulder of the bit. The total reaming time for this interval was 0.45 hours. Totally the bit was in good condition thus was run back in hole to continue drilling. In the fourth run the bit drilled meters of formation, av. ROP was 0.88 m/hr in the interval of meters.at the depth of 5550m the ROP dropped to 0.61 m/h, due to lithology changed to 50% of sandstone (conglomeratic compacted mainly with quartzite), 20 % claystone and 30 % siltstone. At the depth of 5552m formation changed to conglomerate 30%, sandstone 50% (conglomeratic compacted mainly with quartzite), claystone10%, siltstone 10% and ROP dropped more (to 0.46 m/h).from the depth of 5558 m continue drilling of hard conglomeratic compacted sandstone mainly with quartzite 70%-80%.At the depth of m the TQ suddenly increased to 9 Kft/lb, SPP dropped from 3850 to 3770 psi with. ROP dropped to 0. Differentialpressure checked, off bottom and on bottom pressure is the same.dhm failed. Decision was made POOH. On the surface the bit was graded as:4-2-wt-n/t-x-i-bt/ct/hc-dmf. The major dull characteristic for the cutting structure was excessivewear, broken and chipped cuttersmainly at the nose and taper. Looking at the wear pattern of the bit we can assume that such wear occurred due to drilling abrasion formations such as conglomeratic sandstone with quartzite. Considering, the ROP was low the bit was rotated in the hole for extended period of time, which resulted such kind of severe wear of cutting structure. Currently, PDC is in non-rerun condition and cannot be considered for further use.

56 RUN: 4 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR616M-J1 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 RESULTS &CONCLUSION - DSR616M-J1 has not accomplished set objectives, but showed impressive performance; - Reasons for low ROP are: Insufficient, restricted WOB due to inclination problem; Formation changes, especially conglomeratic compacted sandstone with quartzite content 70%-80% and conglomerate 20%; - DSR616M-J1 came out to surface in non-rerun condition and cannot be considered for further run. RECOMMENDATION - Apply of recommended drilling parameters may improve average ROP and extend service life of the bit; - Hard formations require high WOB and low RPM to allow bits to penetrate and shear the formation; - Drilling with more WOB in the range 15-20t during drilling hard formation, such as conglomeratic compacted sandstone with quartzite content and conglomerate to improve ROP.

57 RUN: 2 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR613M-D5 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 IADC DULL GRADING INNER OUTTER DULL. LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 2 BT G X I CT/WT/BU/PN HP RIG GRADE: - RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEP. IN:5630 DEP.OUT: 5796 DRILLED: 166 TOTAL HRS: - ON BTM HOURS: 86 TOTAL ROP: - EFFECTIVE ROP:2.36 WOB: 2-7 RPM: 50 D.H.M. RPM: TORQUE:4-7 TOTAL REVs: - Meters Meters Meters Hrs Hrs m/hr m/hr Tone RPM RPM Kft/Lbs Revs TYPE: WBM NOZZ:3x12/32;2x18/32;1x16/32 MW: 16.9 PPG TFA:1.03Sq. In PV/YP: 55/72.9 Cp/Pa FLOW: GPM DP: PSI BIT HHP: 90 HSI:1.58Good IF:603Lbs NOZ.VEL:147Ft/sec BHA1: 8 1/2 PDC Bit / Mud motor /Float sub/ X/O/1 x 6 1/4" DC/ 8 3/8" S.Stab /17 x 6 1/4" DC /1 x 6 1/4" Jar/2 x 6 1/4" DC /X/O /12 x 5 HWDP/; SURVEY: ANG.IN: AZIM IN: ANG.OUT: AZIMOUT: DLS: Meters Meters DEPTH: LITHOLOGIES: Claystone, Siltstone, Sandstone,Limestone, Anhydrite

58 RUN: 2 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR613M-D5 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 BHA2: 8 1/2 PDC Bit / Mud motor / Float sub/ X/O/ 8 3/8" S.Stab /1 x 6 1/4" DC/ 8 7/16" S.Stab /17 x 6 1/4" DC /1 x 6 1/4" Jar/2 x 6 1/4" DC / X/O / 12 x 5 HWDP/;

59 RUN: 2 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR613M-D5 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2

60 RUN: 2 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR613M-D5 BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A RIG:XDEC6/ZJ70 SIZE(Inches): 8 1/2 COMMENTS New 8 1/2 PDC bit DSR613M-D5 was run in the hole at the depth 5630m. The objective for this bit was to drill remaining part of 8 1/2 section.totally thebit drilled 166 meters of formation in the interval m, through interbedded layers of Claystone, Siltstone, Sandstone,Anhydrite, Limestone, with average ROP 1.93m/hr. The subject bit was two times pulled to surface, while drilling above mentioned interval. In the first run the bit drilled meters of formation, av. ROP was 2.12 m/hr in the interval of meters. At the depth of it was made a decision to POOH due to core point. On the surface the bit was graded as:1-1-bt-g-x-i-ct/wt-cp.the major dull characteristic for the cutting structure was slight breakingof the cutters on the bit`s gauge. The total reaming time for this run was 3.45 hours.overall the bit was in good rerun condition, thus was run back in hole to continue drilling. Inasmuch as coring assembly could not reach TD due to unstable hole condition, decision was RIH withdsr613m-d5. In the second run the bit drilled meters of formation, av. ROP was 1.75 m/hr in the interval of meters.drill string was stuck in the hole at the depth of 5796 m. After release the drill string, it was made decision to POOH due to hole problems. On the surface the bit was graded as: 1-2-BT-G-X-I-CT/WT/BU/PN- HP.The major dull characteristic for the cutting structure was some broken cutters on the gauge of the bit. Also the bit came out to surface with bulled up and plugged nozzles by rubber from DHM. Since the bit was run twice, in the first run had some broken gauge cutters, but was otherwise in excellent condition so was re-run. The reason for broken gauge cutters is excessive reaming. The total reaming time for this run was 24 hours. Thus, those broken cutters were the start of the damage on the 2nd run. When the bit has a broken cutter, the cutters next to it, and also the next cutter in the spiral order have to take more loads, and therefore break more easily than normal. Currently, PDC is in re-run condition and can be considered for further use. RESULTS &CONCLUSION - DSR613M-D5has not accomplished set objectives due to hole problems; - DSR613M-D5 was used two times on CP-Ex1well; - DSR613M-D5 has showed good performance in both intervals; - After two intervals DSR613M-D5 came out to surface in re-run condition; NOV Downhole recommends: RECOMMENDATION - For reaming operations use milled tooth bit instead of PDC bit, to avoidpremature wear of cutting structure of PDC bit. - Consider particular PDC type as one of the good options for drilling 8 ½ section with similar application.

61 RUN: 2 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:R30AMP BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D RIG:XDEC6/ZJ70 SIZE(Inhes):8 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 1 1 BT N E I JD/ER/WT LOG RIG GRADE: - RE-RUNNABLE: YES DRILLED OUT SHOE: NO REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEP. IN: DEP.OUT: DRILLED: TOTAL HRS: ON BTM HOURS: TOTAL ROP: EFFECTIVE ROP: WOB: RPM: D.H.M. RPM: TORQUE: TOTAL REVs: 5013 Meters 5016 Meters 3 Meters - Hrs 7.8 Hrs - m/hr 0.77 m/hr 2-12 Tone 50 RPM 110 RPM 4-6 Kft*Lbs Revs TYPE: MW: PV/YP: WBM /27.1 PPG Cp/Pa NOZZ:3x20/32 TFA:0.93Sq. In. FLOW:401GPM DP:3800PSI BIT HHP:58 HSI:1.03Good IF:414Lbs NOZ.VEL:140Ft/seg BHA 1: 8 1/2" Bit/ Mud motor/ Float sub/x-over/6 1/4"MWD/ 6 1/4"NMDC/8 3/8" S.Stab/ 18 x 6 1/4"DC / 1 x 6 1/4"Jar /2 x 6 1/4"DC / X/O / 12 x 5 HWDP/; ANG.IN: AZIM IN: ANG.OUT: AZIMOUT: Meters Meters LITHOLOGIES: Claystone, Siltstone DATE: _28 October 2012_ Rig Manager: Drilling Supervisor:

62 RUN: 2 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:R30AMP BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D RIG:XDEC6/ZJ70 SIZE(Inhes):8 1/2 DATE: _28 October 2012_ Rig Manager: Drilling Supervisor:

63 RUN: 2 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:R30AMP BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D RIG:XDEC6/ZJ70 SIZE(Inhes):8 1/2 Comments R30AMP bit was run twice in CP-Ex1 well. R30AMPis an insert bit (IADC 5-3-7) designed for soft to medium formations with high compressive strength. The objective for the first run was to clean out the junk in the hole possibly left from previous run S21G bit and continue drilling from the depth 5013 m depending on ROP. Totally this bit drilled 3 meters of formation through layers of Claystone and Siltstone with average ROP 0.54 m/h. At the depth 5016 it was made a decision to POOH to replace Insert bit with PDC. In the subject run the bit was rotated for76752 revolutions. The reason for low ROP was limited WOB (not more than 12t) due to weight below jar was 18t. Whereas Weight On Bit Range by bit specification is 9-27t. On the surface the bit was graded as:1-1-bt-n-e-i-jd/er/wt-bha.the visual inspection of the bit revealed that the cutting structure of the bit was in good condition except one broken insert. And on the cones were observed junk damaged traces which occurred due junk in the hole left by previous milled tooth bit. Second time R30AMP RIH to ream the vertical section from the depth 5579 to 5805 m, logging tools could not reach TD due to hole condition was not stable (regular TQ spikes up to 15 kft*lb, tight spots and overpulls up to 10 t). Totally this bit reamed 226 meters for hours. Overall R30AMP came out to surface in rerun condition and had capabilities to continue drilling with higher ROP if not the obstacle (Insufficient WOB) limiting its performance. Results & Conclusion R30AMP has accomplished the mainset objective (clean out the junk in the hole); Reason for low ROP isinsufficient WOB due to not enough DC; R30AMP came out to surface in good condition and can be considered for re-run; Recommen dations R30AMPis recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs; Drilling with more WOB in the range 18-20t to improve ROP; DATE: _28 October 2012_ Rig Manager: Drilling Supervisor:

64 RUN: 1 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:S21G BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D RIG:XDEC6/ZJ70 SIZE(Inhes):8 1/2 INNER OUTTER DULL. IADC DULL GRADING LOCATION BRNG / SEALS GAUGE 1/16 OTHER REASON PULLED 4 1 BT N/M F I JD BHA RIG GRADE: - RE-RUNNABLE: NO DRILLED OUT SHOE: YES REPAIRABLE: NO RUN INFORMATION MUD INFORMATION HYDRAULICS DEP. IN: DEP.OUT: DRILLED: TOTAL HRS: ON BTM HOURS: TOTAL ROP: EFFECTIVE ROP: WOB: RPM: D.H.M. RPM: TORQUE: TOTAL REVs: 5010 Meters 5013 Meters 3 Meters - Hrs 5 Hrs - m/hr 0.6 m/hr 8-10 Tone RPM - RPM 5-7 Kft*Lbs Revs TYPE: MW: WBM PPG NOZZ:3x20/32 TFA:0.93Sq. In. PV/YP: 37/17.7 Cp/Pa FLOW:542GPM DP:3830PSI BIT HHP: 147 HSI:2.59Good IF:770Lbs NOZ.VEL:189Ft/seg BHA: 8 1/2" Milled tooth bit /Bit /Float Sub/ 18x6 1/4" DC / 1 x 6 1/4"Jar / 2x6 1/4" DC/ 1 x 6.5 X/O/ 15 x 5 HWDP/; ANG.IN: AZIM IN: ANG.OUT: AZIMOUT: Meters Meters LITHOLOGIES: Claystone, Siltstone Rig Manager:

65 RUN: 1 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:S21G BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D RIG:XDEC6/ZJ70 SIZE(Inhes):8 1/2 Rig Manager:

66 RUN: 1 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:S21G BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D RIG:XDEC6/ZJ70 SIZE(Inhes):8 1/2 Comments S21Gis a milled tooth bit (IADC 217) designed for medium to medium-hard formations with high compressive strength. The objective for news21gwas to drill out cement and continue drilling 8½ section (depending on ROP). From the depth 4940m the subject bitdrilled out cement, cement plug, top float collar, bottom float collar and float shoe. And bit drilled 3 meters of a new formation in the interval of meters, through interbedded layers of claystone 90% and siltstone10%. Accumulating av. ROP of 0.6 m/hr. In the subject run the bit was rotated for revolutions. Axial vibrations and Torque spikes up to 15 Kft/lb were observed while drilling above mentioned interval.axial vibrations usually occur during drilling hard formations with roller cone bits. It was not possible to prevent axial vibrations by increasing WOB due to not enough DC in BHA. At the depth 5013 meters decision was madepooh due to undesirable ROP.The reason for low ROP was limited WOB (not more than 10t). Whereas WOBrange by bit specification is 5-20t.On the surface the bit was graded as:4-1-bt-n/m-f-i-jd-bha. The major dull characteristic for the cutting structure was broken and chipped teeth on nose and middle row of the bit which indicates on axial vibrations. Considering that the wear pattern was not similar on each cone, we make conclusion thatcutting structure of the bit suffered mainly from shock actions, possibly caused by combination of downhole vibrations. S21G is in non-rerun condition and cannot be considered for further use. Results & Conclusion S21G has accomplished set objectives; Cutting structure of S21Ghas suffered from shock actionscaused by combination of downhole vibration; S21Gis in non-re-run conditionand cannot be considered for further use. Recommen dations S21G is recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs. Rig Manager: Drilling Supervisor: