THE UNIVERSITY OF TRINIDAD & TOBAGO ALTERNATE FINAL EXAMINATIONS DECEMBER 2013

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1 THE UNIERSITY OF TRINIDAD & TOAGO ALTERNATE FINAL EXAMINATIONS DECEMER 03 COURSE CODE AND TITLE: [DRLG 300 DRILLING & COMPLETIONS] PROGRAMME: [.A.S.C. PETROLEUM ENGINEERING] DATE AND TIME: DURATION: [3 HRS] PLEASE READ ALL INSTRUCTIONS CAREFULLY EFORE YOU EGIN THIS EXAMINATION INSTRUCTIONS TO CANDIDATES. THIS PAPER HAS 9 PAGES AND 5 QUESTIONS.. YOU ARE REQUIRED TO ANSWER ALL QUESTIONS. 3. Numer and keep all parts of each question together. 4. You must return the question paper along with your answer ooklet and other writing paper to the invigilator at the end of the examination. 5. CANDIDATES ARE REQUIRED TO PROIDE THEIR OWN SCIENTIFIC CALCULATORS. 6. Correct units MUST e stated for answers. 7. The examination is CLOSED ook. Key Examination Protocol. Students please note that academic dishonesty or cheating includes ut is not limited to plagiarism, collusion, falsification, replication, taking unauthorised notes or devices into an examination, otaining an unauthorised copy of the examination paper, communicating or trying to communicate with another candidate during the examination, and eing a party to impersonation in relation to an examination.. The aove mentioned and any other actions which compromise the integrity of the academic evaluation process will e fully investigated and addressed in accordance with UTT s academic regulations. 3. Please e reminded that speaking without the Invigilator s permission is NOT allowed. The University of Trinidad & Toago Page of 8 Decemer 03 Alternate Final Examinations DRLG 300

2 QUESTION 0 marks A. List four main design features of land rigs. marks. A power of 000 hp. Ten lines are strung etween the crown and the traveling lock and the dead line is anchored to a derrick leg on one side of the v-door. Given that the power efficiency factor for ten lines strung is 0.80, calculate the following: a The static tension in the fast line when upward motion is impending. marks The maximum hook horsepower availale. marks c The maximum hoisting speed. marks d If the driller is allowed to pull the pipe at 80% of the maximum hoisting speed, how long will he take to pull 0 stands of DP, if each stand is /- 90 ft long. Connection & rackack time is 3 mins/std. marks e Derrick load when upward motion is impending. marks f The maximum equivalent derrick load. marks g The derrick efficiency factor. mark C. A duplex pump fitted with 6 diameter liners,.5 rods and stroke length is operating at 00 strokes/ minute at an efficiency of 85%. The total circulation volume of the well is 70 ls. a Compute the flow rate in GPM. 3 marks Compute the time required to make a complete circulation of the well. marks QUESTION 0 marks a riefly descrie the significance of each of the following tests, which are commonly reported in API Drilling Mud Report form. i. Gel strength mark ii. Mud density iii. Filtrate API mark mark The University of Trinidad & Toago Page of 8 Decemer 0 Alternate Final Examinations DRLG 300

3 A drill string is composed of 5 inch OD x 4.76 inches ID, 9.5 l/ft, drill pipe and drill collars with 8.0 inches OD x.75 inches ID is on ottom of well at 000ft. The mud density is.5 ppg. The required weight on it for the formation eing drilled is lf. Determine the length of drill collars required to maintain weight on it and show what length of drill collars are required to maintain a 30% excess 3 marks c Compute the volume and density for a mud composed of 35 ls entonite 90 ls/l, 70 ls API arite 470ls/ l and l fresh water 350ls/l marks d A mud sample in a rotational viscometer, equipped with a standard torsion spring, gives a θ600 reading of 38, and a θ300 reading of. Calculate the following and show correct units for each answer. a Apparent viscosity at 600 rpm mark Plastic viscosity mark c Yield point mark d It is desired to increase the density of 800 ls 0f ppg mud to 4 ppga final volume of 800 ls is required. Compute the following: What volume of original mud should e discarded? Weight of API arite to e added How many arrels of fresh water must e added? 3marks Assume density of arite is 35 l/gal, density of water is 8.33 l/gal,.0 gall of fresh water / l arite and one sack of arite is 94 ls. Question 3 0 marks a A pump is eing operated at a rate of 450 gpm and a pressure of 300 psig.the mud weight is ppg and the total nozzle size is sq. in. C d 0.95 Compute the power developed y the pump. 3 marks Compute the power loss due to viscous effects. 3 marks Compute the impact force of the jets against the ottom of the hole. 3 marks The University of Trinidad & Toago Page 3 of 8 Decemer 0 Alternate Final Examinations DRLG 300

4 While drilling with a.5 inch it, and a 5 OD DP string with a.0 ppg mud, the Reynolds numer for flow in the DP/OH annulus was determined to e 300, for a pseudoplastic Power law fluid with a Flow ehavior Index n of The DP/OH annular velocity was also determined to e 3.8 ft/sec. If the length of the drillpipe/open hole section is,000 ft, calculate the friction pressure loss in the annulus. 6 marks c Determine the pressure at the ottom of the drill collars if the frictional loss in the drill string is 000 psi, flow rate 380 gpm, mud density 0.5 ppg, drill collar id.5, depth of 8000 and pump pressure is 600 psi. 3 marks d Write a formula showing the pressure losses in the whole circulating system. marks QUESTION 4 0 marks a Descrie the design if of roller cutter it to e used in soft formation and give the API classification for it. 4 marks The it type currently used to drill a given formation consistently yields a drilling cost of $ 50/ ft. You are sending a new experimental it type to the field for evaluation of this formation. The new it is expected to have a it life of 50 hrs as compared with the usual it life of 5 hrs. Cost of new it is $ 0,000, drilling rig cost is $ 750/ hr, trip time is 0 hrs for depth of interest. The reak-even cost is $ 50/ ft. If the initial penetration rate for the new it during the first hour is 4 ft/ hr, what would you recommend? Answer Yes/No, Show working. 5 marks c A rock sample is placed in a strength testing machine at atmospheric pressure and compressed axially to failure. A force of,000 lf was required for rock failure, and the cross sectional area of the sample was inch. The failure occurred along a plane of 35 0 with the direction of the compressional load. Using the Mohr s failure criterion, determine : The shear stress along the plane of failure marks The normal stress to the plane of failure marks The angle of internal friction mark The cohesive resistance of the material mark The University of Trinidad & Toago Page 4 of 8 Decemer 0 Alternate Final Examinations DRLG 300

5 d Name and sketch four well trajectories and riefly descrie three methods of deviating a Well. 5 marks Question 5 0 marks a What are the three most commonly recommended methods of directional survey computation used? 3 marks It is planned to do a kickoff in a well at a depth of 800 ft, using a mud motor and ent su assemly. At the KOP, the direction survey indicates an angle of 5 degrees and direction of S40W. It is desired to turn the wellore to the right and the new wellore angle and direction at the end of the motor run is expected to e 9 degrees and N50W, with a planned course length of 300 ft. The mud motor, at this depth and inclination, has a reverse torque of 5 degrees to the left. Calculate :. The tool face setting γ, relative to high side, that the directional driller must use for the motor run. 5 marks. The dog leg severity for the motor run 4 marks c Sketch a packed assemly and give its use marks d Explain how differential sticking occurs marks e State three advantages of drilling a horizontal well and state the the type of rotary drive required for this operation giving an appropriate reason 4 marks The University of Trinidad & Toago Page 5 of 8 Decemer 0 Alternate Final Examinations DRLG 300

6 USEFUL FORMULAE END OF EXAMINATION ώ π radians/min P ώ T µ a 300. θ N /N µ p θ θ 300 τ p θ µ p F f W E. n P E. P h i P h E E. n F d W W E. n F de n 4 n W E d Fd Actual Derrick Load F Max Eqv Load de C f C C t r D t c t t t Rotating time ; t c Non-rotating time t t Trip time; C it cost ; C r rig cost v q fv P L.448 d h d p. d d h p The University of Trinidad & Toago Page 6 of 8 Decemer 0 Alternate Final Examinations DRLG 300

7 The University of Trinidad & Toago Page 7 of 8 Decemer 0 Alternate Final Examinations DRLG 300 w w w w w w m w Capacity 09.4 D l/ft i i i M c c f f w w w M F - M W 65.5 sin 3 φ σ σ τ t d A C q x p

8 β arc. coscos ε.sinα N.sinα cosα.cosα N cosα.cos β cosα N γ arc.cos sinα.sin β δ β L C 00 USEFUL CONERSIONS TU 779 ft-lf HP 33,000 ft-lf/min gal 3 cu inches l 4 gals cu ft 7.48 gals The University of Trinidad & Toago Page 8 of 8 Decemer 0 Alternate Final Examinations DRLG 300

THE UNIVERSITY OF TRINIDAD & TOBAGO

THE UNIVERSITY OF TRINIDAD & TOBAGO FINAL ASSESSMENT/EXAMINATIONS APRIL 2014 Course Code and Title: Programme: Date and Time: Duration: HYDRAULICS FLUD2006 BASc. Civil Engineering Wednesday 16 th April,