Highlights of Achievements at Loc. TU

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Hope Nash
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2 Highlights of Achievements at Loc. TU Planned-80 days / Actual-74 days. Different BHAs for drilling in rotary mode designed by in-house expertise. Sliding was limited to<8%. Regulated a huge rotary torque of lbs-ft. Under Rated Drilling Rig. Utilized Jar Accelerator to release stuck time in India). Hole was 90% True Gauge Drilled Longest 17.5in hole section (2150m) with inclination of 35.7 deg No major down hole complicacies. PDC bit drilled 90% of 8.1/2 hole section in single trip

3 Creation of Loc.TU Geological requirement Surface to sub-surface target distance 1942 m. Target TVD 3982 m. Challenges THD of 1942 m was never achieved in OIL history. Available directional tool was only Mud-Motor & MWD Rig limitation Non-availability of high performance directional PDC BIT Cont..

4 Creation of Loc.TU Support Directional software Landmark COMPASS WELLPLAN TORQUE & DRAG, ANTICOLLITION & HYDRAULICS CASING DESIGN Past experience of J-Bend well (Shorter THD) Outsourced directional service and in-house expertise Parameters considered for designing: lesser drag Low surface torque Hydraulics for optimum hole cleaning

5 3 designs were worked out for 8.1/2 hole section PLAN-1 PLAN-2 PLAN-3 250M 1000M 2000M DLS(deg/30M) Max Surface Torque(kft-lb) Max Drag at surface T Max MD(M) Max Inc(deg)

6 Plan-2 PLAN 2 was selected to drill the well with following policy: Kick off at 17. ½ section Minimum sliding in tangent section. Use PDC bit longer duration of drilling in 8. ½ section. S Grade Drill Pipes were used to mitigate high torque. Monitoring mud-lubricity and proper mud rheology

8 Success story of Loc.TU (Plan-2)

9 HOW TARGET WAS ACHIEVED 24/7 round the clock discussion (onsite & offsite) with well site DD & Mud Engineers for smooth operation. Unusual BHAs were successfully tried. All practical calculations (Torque& Drag- Hydraulics)in all operational steps were done with the help of in-house directional software Variable adjustable drilling parameters were applied. The main point in this entire operation is that everything was well planned & executed with all possible knowhow, software support, experience & knowledge & out of the box thinking.

10 PLAN VS ACTUAL

12 Before the TD was achieved the well encountered dynamic losses of around 30 bbls. In view of this loss problem, it was decided not to use conventional slurry of 118 PCF weight and Schlumberger was advised to use light weight cement slurry. Accordingly cement program was designed with 12.5 ppg (93.5 PCF) lightweight slurry (LiteCRETE*) which is a blend of Cement, Cenosphere (D181 & D124) & Micro silica particles (D178). NS Cement is dry blended with these three chemicals at ABHP. Subsequent CBL-VDL of 5.1/2 casings revealed good bonds.

0 m Min Slurry Volume BHST : 114 0 C Challenge : Losses during

13 3600 m 4100 Zones of interest Well : Barekuri-15 Location : TU MD : m Min Slurry Volume BHST : C Challenge : Losses during drilling beyond ppg ECD Slurry design LiteCRETE HP : 12.5 ppg 4600 Volume : US bbl Slurry rise : m

14 Normal Cement LiteCRETE* (CemCRETE*) Trimodal Particle Size Distribution - Ball bearing effect High Solid Volume Fraction and low water content Light weight Coarse particles - Low density Free water Fluid Loss Rheology Advantages Mixability Stability Compressive Strength

15 LiteCRETE 12.5 ppg Additive Code Concentrati on Componen t D gal / sk Anti foam D % BWOC Fluid Loss D % BWOC Dispersant D181 D124 D181 D600G 0.20 gal / sk GASBLOK D % BWOC Retarder D % BWOC HP Extender D181 D124 D181 D % BWOC Silica D % BWOC Extender Pv / Ty Thickening time 165 cp / 11 lbf/100ft2 05:20 hh:mm Class G Cement D178 Fluid Loss 48 ml / 30 Min SGSA Transition Time 40 minutes Compressive Strength 2000 Psi

16 THANK YOU

17 Past Experience The first directional well Loc.NCP, NHK#122 was drilled in 1962 Well depth ft, KOP 4949 ft in 8.1/2 hole, THD 1350 ft Till 2005, directional drilling was limited to S-type (using SS Tool) only. Subsequently, horizontal drilling was first introduced in OIL in the year With the new idea of MWD and SDMM 7 J-Type wells (Loc. HSD, HSN, HSE, HSJ, HOR, HTN and HQF) were planned and drilled during During drilling those J-Bend wells lot of down hole complicacies occurred, Due to successive failures, concept of J-Bend was discontinued temporarily.

18 J Bend well drilled under new contract In 2013 a new contract was made to drill 16 No. J-Bend wells. KOP was selected in such a way to maintain the inclination between deg to avoid hole cleaning issues. Switch over to 4 stages of casing policy from 3 stage in case of eocene wells Planned 8. ½ open hole section within m ( pay zone section) To drill and case as fast as possible, to minimized the exposure time Loc. HSH, HSW, HTW was drilled successfully in Dikom area Drilled faster in Loc. BGN, MFN, MFP through re-designing of BHA to drill in rotary mode as far as possible.

19 Rig CH# HP 2000HP rig having 3 nos. of rig pumps with topdrive is required for smooth operation. Existing CH#3 rig is under due to following reasons: Existing rig equipment Actual requirement 3 nos. of 1569 HP engines 4 nos. 2 nos. of triplex pumps 3 nos. Kelly Drive Top Drive No rotary torque gauge Required in ft-lbs

Successful New Technology Introduction and Applications of Rotary Steerable System.

Successful New Technology Introduction and Applications of Rotary Steerable System. Mohammed Ibrahim Schlumberger Copyright 2003, MPC 2004 This paper was prepared for the 8th MEDITERRANEAN PETROLEUM CONFERENCE