Drilling in a single run with 52% more DLS | SLB

Drilling an 8.5-in section in single run with 52% better dogleg optimization

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India, Asia, Onshore

At an onshore operation in India, Cairn Oil & Gas, Vedanta Limited leveraged the AccuStrike™ short-makeup drill bit from SLB to drill a challenging well profile in an 8.5-in section. In addition to achieving this in a single trip, the AccuStrike bit delivered a more than 52% improvement in attaining dogleg severity (DLS) while enabling the customer to land at the target zone.

In India, Cairn Oil & Gas, Vedanta Limited wanted to drill a challenging wellbore profile in an 8.5-in section, starting with a vertical drilling ascent and then transitioning to horizontal drilling all in a single trip. The profile was planned in soft and low compressive strength rocks prone to washouts with DLS limited to low angles when using a rotary steerable system (RSS) assembly. To succeed, a drillbit design was required that could deliver the desired dogleg from the PowerDrive Orbit G2™ RSS BHA throughout the interval length.

Using the AccuStrike bit on the PowerDrive Orbit G2 RSS BHA enabled dropping the well from 19° to vertical and then building to 93° at an average DLS of 5.1°/100 ft at just 60% steering force. This DLS output represents an improvement of more than 52% in comparison with the performance of a conventional PDC matrix bit on the same BHA in nearby fields. More than high angle DLS, the AccuStrike bit achieved a consistent 8°/100 ft in a soft sand interval, enabling the customer to position the well at the target zone.

AccuStrike drill bit’s one-piece steel body PDC architecture was instrumental in driving the improvement in DLS. Furthermore, despite facing challenging drilling conditions, the cutting structure showed minimal damage to the cutters, and the bit was pulled out in a condition suitable for reuse.

Pre- and postrun photos of AccuStrike bit condition and table documenting dogleg performance.
AccuStrike short-makeup drill bit delivers an improvement of more than 52% in achieving optimum DLS to access the target zone.

Single Trip with AccuStrike Short-Makeup Drill Bit

Run No. Drilled, m From, m MD To, m MD From, m TVD To, m TVD Formation
1 707 1,333 2,040 1,282.43 1,757.01 Predominantly claystone and
Predominantly clay stone and landing internal in sandstone
Distance, m Time, h ROP m/h
Sliding 0 0 0
Rotary 707.00 30.50 23.18
On bottom 707.00 30.50 23.18
International Association of Drilling Contractors (IADC) 707.00 30.50 23.18
Products Used