Borehole Geometry Logging

Transcription

1 Borehole Geometry Logging

2 Borehole Geometry Log Measurement of borehole diameter & orientation Mechanical arms are pressed against the borehole wall, variations in hole diameter close and open the arms, which are linked to e.g. potentiometers. 1-arm 3-arm - Planning of cementations (hole volume) - Borehole directional corrections - Stress field orientation. Orientation section with magnetometers or kompass and pendulum (centralizers). 6-arm! Attention in inclined boreholes with strong breakouts (keyhole): Long axis readings may be too small! 4-arm low side of borehole 4-arm caliper section GFZ-OSG, J. Kück

3 Types of Borehole Enlargement In-gauge Breakout Washout Caliper bit size GFZ-OSG, J. Kück

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5 Orientation Sonde Principles Direction of High Side of Tool (angle btw. high side & North) Hole Azimuth North Relative Bearing (angle btw. high side & Pad 1 High Side of Tool Deviation (Inclination) (angle btw. sonde axis & vertical) Pad #1 Vertical GFZ-OSG, J. Kück

6 Stress Field Direction from Oriented Caliper Logs Long Axis Direction = Break Out Direction North Azimuth Caution with high cable torque! Long Axis Direction Difference Sh SH Cable torque rotates sonde GFZ, OSG, J.Kück

7 0 borehole deviation [deg] Borehole 1000 Inclination VB (Deviation from vertical) depth [ m ] HB Example: KTB-VB & HB 9000 GFZ, OSG, J.Kück

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9 Distance from starting point [m] Example: KTB-VB pilot hole Depth [m] DEVI = 4?Z = 30 m DEVI = 1 DLS = 1 /10m Dogleg Severity DogLeg Borehole Orientation Measured data: - hole deviation angle DEVI - hole azimuth angle AZIM - depth Z Derived parameters: - true vertical depth TVD - horizontal deviation HD - West/East deviation WE - South/North deviation SN WE South -North Depth HD West-East SN TVD borehole path GFZ-OSG, J. Kück

10 Borehole Geometry Log Parameters: Cal1 & Cal2: caliper 1 & 2 DEVI: hole deviation (from vertical) AZIM: hole azimuth RB: relative bearing P1AZ: azimuth of arm #1 derived: TVD: true vertical depth HD: horizontal distance NS,EW: north-south, east-west distance GFZ-OSG, J. Kück

11 0 Vertical Projections of the Borehole Path Example: KTB-HB main hole 0 Depth/m West Distance/m East North Distance/m South GFZ, OSG, J.Kück

12 Borehole Trajectory (Borehole Path) Example: KTB main hole (HB) East depth / m North Surface starting point GFZ, OSG, J.Kück

13 Horizontal Projection of the Borehole Path 200 North m Example: KTB-VB pilot and KTB-HB main hole VB HB 9069m Distance / m m 1000m 3000m 8077m 8000m 4000m South m West Distance / m East GFZ, OSG, J.Kück

14 200 North 150 Error of the Horizontal Projection Example: KTB-HB main hole 9069 m Distance / m Radius = 25 m South m West Distance / m East GFZ, OSG, J.Kück

15 Comparison of Borehole Path Characteristics 15 North VB HB Distance / m 5 0 South West Distance / m East GFZ, OSG, J.Kück

16 Comparison of Borehole Path Characteristics

17 Borehole Situation after a Side Kick Operation Example: KTB-HB West - East Plane Depth [m] South - North Plane Kick Off at 7165 m Old Borehole 7190 New Borehole 7200 New Borehole Old Borehole Bitsizes = 310 mm GFZ-OSG, J. Kück

18 Temperature Logging

19 Temperature Sonde Parameters: T or TEMP: Temperature T-Sensor inside cage

20 0 depth/m Log No: 1992 / / / / Temperature distribution in a deep borehole temperature / C Example: KTB-HB pilot hole GFZ-OSG, J. Kück

21 depth/m KTB HB main well Temperature distribution in a deep borehole depth [m] temperature [ C] temperature / C Example: KTB-HB pilot hole GFZ-OSG, J. Kück

22 Bottom Hole Temperature Prognosis The Bottom Hole Temperature (BHT) can best be approximated from a series of stationary temperature measurements at bottom hole. Each stationary measurement should be longer than 10 minutes to allow the sonde body to accomodate to temperature (heat up). 270 BHT/ C Horner Plot approximated final BHT = 262 C Example: KTB-HB 9100 m (?t+t c )/?t GFZ-OSG, J. Kück

23 Temperature Profiles 0 0 near Equilibrium depth /m JAN JAN MAR KTB-HB 4000 T reduced = T meas - (7.5 C+Zx27.5 C/km) 22-MAR JAN JAN max. temperature 248? C at 8549 m TÅ> 265? C at 9100 m temperature / C reduced temperature / C GFZ-OSG, J. Kück

24 depth/m Temperature Profiles KTB-HB before injection dn dn dn while Testing T reduced = T meas - (7.5 C+Zx27.5 C/km) before injection dn dn dn temperature / C reduced temperature / C GFZ-OSG, J. Kück

25 Logging Quicklook Presentation The daily drilling routine urges for a fast and comprehensive presentation of the freshest wireline data. A Quicklook-plot is a composition of Geometry & Mudparameter Logs together with important drilling and field lab data as soon as the data becomes available (i.e. immediately after logging). min & max Caliper, Deviation, Azimuth, Breakout Azimuth Dog Leg Severity, Ellipticity, Roughness, Hole Volume, Mud Resistivity, Mud Temperature, Lithology, BHA (bottom hole drilling assembly) depth Cmin C max Bitsize 3000 DEVI AZIM BOAZ DLS Litho logy Ellipt Rough MRES BHA Horiz. Dist N - S W - E Volume On additional plots: Borehole Projection & temporal Breakout Development GFZ-OSG, J. Kück