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Case Study: Cairn Energy Sees 47% Improvement in Footage Drilled with SHARC Drill Bit

PDC delivers record durability and competitive ROP in hard and abrasive weathered volcanics

Challenge: Reduce the number of bits required to drill the 6-in producing sections of multiple wells in Raageshwari field, while maintaining good ROP.

Solution: Use SHARC high-abrasion-resistance PDC drill bit equipped with ONYX PDC cutters for superior durability and maximum ROP.

Result: The SHARC bit drilled 47% more footage compared to all previous efforts, with ROP above the median offset value and a dull bit condition that confirmed the bit could be used for additional runs.

Hard, abrasive weathered volcanics challenges drillbit durability and ROP

The 6-in production sections of wells in Cairn Energy’s Raageshwari field in Rajasthan, India, are 600 m to 800 m long. The section starts in the Fatehgarh formation and continues through hard, abrasive, weathered volcanic formation with unconfined compressive strengths (UCS) ranging from 15,000 to 30,000 psi. The directional profile of this section usually involves a minor build from about 10°–15° to 20°–30°, with a dogleg severity (DLS) of 1°–2°/30 m. Previous bits drilled a maximum of two wells per bit before excessive wear rendered them unsuitable to run on subsequent wells; more wear-resistant systems had provided very low ROPs. Cairn Energy wanted to reduce bit costs by using a durable bit that could drill more than two, 6-in sections with a competitive ROP.

SHARC bits and ONYX PDC cutters provide superior wear resistance

The SHARC 6-in MDSi613 high-abrasion-resistance PDC drill bit was selected for the job. SHARC bits are specifically engineered to minimize vibration, resulting in increased stability and wear resistance without sacrificing ROP. Two rows of cutters are set on each blade, with each row reinforcing the other, providing maximum durability over the nose and shoulder areas of the bit and ensuring consistently high ROP. The rows are oriented to ensure hydraulic cleaning and cooling efficiency.

To further enhance performance, the bit was equipped with ONYX PDC cutters, which have improved thermal properties with greater wear resistance and fatigue life than conventional PDC cutters. ONYX cutters stay sharper longer than standard PDC cutters, meaning more footage at higher ROP and reduced cost. The bit was certified by IDEAS integrated drillbit design platform, which takes into account the dynamic rock/cutter interface and the entire BHA.

Drilled footage exceeded previous maximum by 47% with good ROP

The SHARC bit was the first bit to drill 6-in sections for three consecutive wells in the field—a total of 2,328 m, 47% more than than all previous efforts. Average ROP was 10.7 m/h, which was above the median ROP of 10.3 m/h for this application. The dull grading of the bit after three runs was 0-1-CT-A-X-IN-NO-TD; it drilled an additional 1,459 m in another field at an average ROP of 56.4 m/hr and remained in a usable condition.


Download: Cairn Energy Sees 47% Improvement in Footage Drilled with SHARC Drill Bit (0.68 MB PDF)

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Offset cumulative run length versus SHARC MDSi613
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Superior Wear Resistance

SHARC 12 1/4-in MSi716LEBPX PDC with ONYX cutters
SHARC bits are specifically engineered to minimize vibration, resulting in increased stability and wear resistance without sacrificing ROP.
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