Monitoring of torque and drag in 12.5’’ section

We can divide this section in three different layer as three different zones. The zones are

Section 12.25 inches

Run

Bottom Hole Type

Start Depth

Stop Depth

1 Motor BHA 1164 m 1726 m

2 RSS BHA 1726 m 3017 m

3

Rotary BHA with

power drive 3017 m 3503 m

Run # 1 (1164 m -1726 m)

Operational Summary:

This section started with a contingency plan of running a motor BHA to avoid the repeat of earlier RSS run as the formation was still relatively soft. A 12 1/4” Smith mill tooth bit (IADC 1-1-7) was lowered with the string including Powerpak motor, float sub, ARC, Telescope, Sonic and SADN. The first shallow hole test was carried out with 700gpm and SPP of 650psi before loading radioactive source into the SADN. After loading radioactive source into the SADN the string was RIH to first stand of HWDP and perform second shallow hole test with 700 GPM and SPP of 800 psi.RIH to top of cement at 1045m and drilled out to float collar at 1066m. The float collar and cement was drilled out to shoe at 1103m using sea water and maintaining 2 to 10 klbs WOB, 40 RPM and flow rate of 800gpm. Resume drilling sliding to build angle and catch up with the plan. The flow rate was maintained at 800gpm to avoid washing the formation as it was still very soft sand. Continue drilling and gradually stage up flow rate to 950gpm and maintaining ROP below 50m/hr to improve hole cleaning while building angle and aligning azimuth as required by plan. At TD, pump Hi-vis and circulated bottoms up two times with the string being stage out after 30mins to avoid hole washout.

Observation from Torque and drag graph :

In this region the Hook Load shows a very good resemble with the simulated line bearing the FF 0.2 and 0.3.The real time data in Tripping in and Tripping out both shows the FF is in between 0.2 and 0.3. Moreover the real time Hook Load data doe6 not show any abnormal trend compared with the simulated line in the Tripping in and Tripping out graph. But from the Torque graph it shows that the initial value of the Torque is fluctuating frequently showing the FF 0.3 to 0.4 in this region. It shows the necessity of giving more effort in the hole cleaning at the beginning of this section.

76 Run#2 (1726 m -3017 m)

Operational Summary

This section was drilled with a RSS BHA. A 12 1/4” Smith MDi519 LPBX bit, PowerDrive X5, ARC, Telescope, Sonic and SADN was picked up. RIH and drilled from 1726 m to 2194 m. While drilling this section, flow rate of 950 gpm and string RPM of 140 was maintained throughout. Prior to connections each stand was washed up and reamed down and MWD survey was taken prior to making connections. At 2194 m it was decided to do a wiper trip.. Circulated at 950 gpm and 140 rpm for three bottoms up while raking back a stand every 30 minutes. After three circulations tried to trip out on elevator, observed 50 k overpull at 2100 m. RIH 5 meters and circulated for 20 minutes and tried to POOH on elevators. Observed, 50 k over-pull. Commence reaming. While back-reaming, torque was normal and there were no indications of hole cleaning or well bore stability issues. Back-reamed till 1986 m and then tried again to trip out on elevators. Observed 40-50 k overpull. Drilled ahead from 2194 m and gradually started to increase MW from 9.5 ppg to 10 ppg.

Drilling parameters and connection procedures were maintained. Drilled to 2705 m and while washing up observed over-pull. Decision was made to do a wiper trip one stand earlier than originally planned. Circulated 4 bottoms up while racking back one stand every 45 minutes. RPM was kept constant at 140 rpm. After circulation, an attempt was made to trip out on elevators. It was taking 50 k overpull. Ream out of hole till 2166 m and then RIH to bottom without any issues.Drilled till 3017 m and decide to POOH to change LWD tools and pick up PBL sub. Ream out till 2506 m and then trip out till 2157 m. Ream out from 2157 m to 2081 m and then trip out of hole.

Observation from Torque and drag graph :

In this region the real time Hook Load data also shows a very good resemble with the predicted Hook Load having different FF. In the Tripping in case the real time Hook Load data matches with the simulated data showing the FF form 0.2 to 0.3 and in the Tripping out condition the real time Hook Load stands for the FF 0.2 for that region. From the Torque it is clear that the extra effort in hole cleaning operation changes the trend of the Torque which shows previously the FF ranges from 0.3 to 0.4. Now in this region the Torque shows the decreasing trend having the FF From 0.2 to 0.3.

Now the FF in both Torque and Hook Load shows the same FF. So Torque and drag monitoring in this region showed that hole cleaning was good and no abnormal drag was observed.

Run#3 (3017 m-3503 m)

Operational summary:

Pick up new Power drive X5 tool along with LWD tools . Pick up PBL sub above SADN8. RIH to 3010 m. Circulated hole clean and dropped ball to open the PBL ports. Circulated for one hour at 1500 gpm, through the PBL sub. Closed PBL sub by dropping the ball and continued to drill ahead from 3017 m. While drilling, flow-rate was maintained at 1000 gpm and string rpm was 140 rpm. 23 stands of WWT drill pipe protectors (torque reducers) were in the in the drill string. Drill till 3503m.

Section TD was declared based on geological correlation with offset well. Dropped ball to open PBL

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sub ports and circulated through the PBL sub at 1500 gpm for one hour. Closed PBL sub and continued to circulate hole clean with 1000 gpm. Reamed out of hole till 2965 m. While reaming out Torque was erratic and higher than the previous wiper trips. Noticed the Ultrasonic calliper was reading almost a gauge hole, considerably less than what it was during drilling. RIH to 3503 m.

Circulated for one hour and then trip out of hole without any problems to surface.

Observation from Torque and drag graph:

In this region both the Tripping in and Tripping out Hook Loa real time data shows a very good resemble with the simulated graph having the FF of 0.2.While drilling ahead observed that there was no increase in off bottom torque and gradually there was a reduction in off bottom Torque. Torque and drag measurements indicated that the Friction Factor was about 0.2.

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