Better Well Control, Well Integrity through downhole information independent from surface data

1. Better Well Control, Well Integrity through downhole information independent from surface data Daan Veeningen

2. Talking Points Reliance on surface data for well control Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections Introduction to networked drillstring and along-string evaluation Supplement downhole information independent from surface data for better well control and integrity Conclusions and recommendations

3. Well Control Critical Issues: • Reliance on surface measurements • Inaccurate flow rate measurements • Limited redundancy to track mud volumes • Conditions such as heave, roll, and pitch • Compromised by plugged lines, hydrates, etc Simultaneous data 57, 600 bits/sec High bandwidth High definition High volume Real time • Limitation of Downhole Measurements • Insufficient data rates • Limited to data from near the bit • Condition unknown during static periods • Compromised by lost circulation, ballooning One-way ## bits/second Broadband, Two-way ##,### bits/second Networked Drillstring Mud Pulse NMR Sonic Gamma Vibration Resistivity Pressure Seismic Etc., etc. Vibration Image logs

4. Networked Drillstring

5. Along String Annular Pressure Evaluation #6 #5 #4 #3 #2 #1

6. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections ≠ • Reliance on (predominantly) surface measurements • Slow influxes difficult to identify • Complexity due to variable densities, U-Tubing • Where is the influx? What is the influx? What is the bottomhole pressure? • Killing the well using surface measurements, using manually prepared kill-sheet... Under stress

7. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections Identify kicks independently from surface measurements Analyze as influx migrates in the annulus Control the well based on Direct Measurement of BHP

8. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections PRESSURE GRADIENT CHANGE IN AN INTERVAL? Y t = 3 t = 2 t = 1 t = 0 #3 BORE, ANNULAR Y WELLBORE PRESSURE DECREASE IN AN INTERVAL? INFLUX* Δ↓ Δ↓ Δ ≈ Δ ≈ N N #2 CONTROL INFLUX (SHUT IN Δ↓ OR DYNAMIC WELL KILL Δ↓ Δ ↓ Δ ≈ #1 OPERATIONS CONTINUE * LARGE ANNULUS

9. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections PRESSURE GRADIENT CHANGE IN AN INTERVAL? Y t = 4 t = 3 t = 2 t = 1 t = 0 • Well control response options are severely limited and the risks of a blowout increase significantly once gas is above the BOPs • In deepwater, the riser comprises a substantial section of the wellbore and productive hydrocarbon zones can be found relatively shallow below the mud line • Decision point: Divert or line-up the mud-gas separator Δ↓ Δ↓ BORE, ANNULAR Y GAS ABOVE PRESSURE DECREASE Δ ≈ Δ ≈ Δ ≈ IN AN INTERVAL? BOP PRESSURE/GRADIENT DECLINE RATE N N HIGH LOW DIVERTER MUD DEGASSER ↓ Δ↓ Δ↓ Δ Δ ≈ Δ ≈ Δ↓ Δ↓ OPERATIONS CONTINUE Δ ↓ Δ ≈ (Patent application pending) BOP

10. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections • Method: • Propagation resistivity time-lapse log with and without ECD • Requirement • Downhole data transmission in the absence of flow • b) Pumps off: Gains • ECD is eliminated and fractures close • Pumps on: Losses • ECD exceeds formation fracture pressure, mud enters fractures

11. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections Resistivity log while drilling Fluid invasion due to ECD Resistivity log while tripping Fluid expelled by eliminated ECD Identify Ballooning zone

12. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections

13. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections Inconclusive Test Bad Test Good Test t=2 t=1 P P P P P ΔP • No preexisting or SOP for negative testing • Heterogeneous fluid densities • Improper line-up, plugged lines (LCM), closed valves • Taking returns into two different pits • Displacement to boats, bypassing surface flowmeters • Properly executed test is time consuming due to PVT effects RISER LCM P P P P P P P P P P P t=1 t=2 t=3 t=1 t=2 t=1 t=2 t=0 t=1 t=1 t=1 t=2 t=2 t=2

14. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections Bad Test Good Test t=1 t=2 t=1 t=2 P P P P • Downhole pressures supplement surface measurements • Save rig time by identifying PVT effects 800PSI P P P P P P P P t=0 t=1 t=2 t=1 t=2 t=1 t=1 t=2 t=2

15. Reliance on surface data for: Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections • Static density before/after connections • Hole cleaning efficiency monitoring • Fluid level detection • Dynamic (surge/swab) during tripping • Strain monitoring

16. Top of Mud N2 injection MW actually 7.35 (dead OBM) Corrected EMW’s MW=6.35ppg?? MW=6.35 SPPR EMW(lwd) EMW(asm2) N2 Injection or 5.63ppg?? EMW(asm1) EMW (ppg) START Pumping Mud Injection N2 not 4.8-5.2 Top of Mud (ft below RKB) Mud level 2300 ft down Courtesy: Schlumberger Time (hrs) • Determine that losses have stabilized before POOH

17. Reliance on surface data for: • Closed-loop automation of surface equipment • Back-pressure pump • Auto-Choke Kick detection, Gas-in-Riser identification Ballooning distinction from a Kick Well Control operation Negative Pressure testing Pipe tripping/connections MPD/UBD Operations • No data without flow, during sever losses, or compressible fluids • Reliance on models • Kick drills with N2 injection • Early detection with magnitude smaller kick volume • 2 sec BHP updates, • Surveys on demand, • Low latency data Courtesy: @Balance, BakerHughes , SPE112651

18. Conclusions and Recommendations Today’s well control and well integrity relies on surface data as downhole measurements are limited Networked drillstring provide high-definition downhole and along-string informationeven in the absence of flow Resolve critical issues with downhole information independent from surface data for detection of kicks, gas-in-riser, and to identify ballooning zones. Direct Measurement Method is suggested for better well control. Alternatives are now available to conduct negative pressure testing, and to obtain information during trips through MWT and to safely conduct MPD and mud cap drilling.

19. Thank You!Questions? Daan.Veeningen@nov.com