Challenge: Drill to TD of 2,320 m while minimizing NPT and risk of drilling through unstable formations

Solution: Use XCD™ casing-while-drilling alloy bit to drill the 20-in section and Allegro CD™ directional casing-while-drilling service for the 9 5/8-in section

Results:

• Achieved ROP of 29 m/h in the 9 5/8-in section, saving 62 hours of rig time

• Drilled 753 m of total footage at ROP of 24 m/h, setting record for section length and depth for 20-in casing drilling in Europe

• Delivered high-quality wellbore, resulting in an excellent cementing job

Minimize NPT and risk of drilling in unstable formations

OMV Petrom, the largest oil producer in Romania, planned to drill a well in the Black Sea to a TD of 2,320 m. Consequently, the operator sought to maximize reliability and efficiency by reducing NPT and the risk of drilling through unstable formations.

Optimize drilling performance with casing bit and casing drilling service

To improve drilling performance in the 20-in section, the Allegro XCD alloy bit from Smith Bits, an SLB company, was recommended. The casing bit is designed to drill out quickly and efficiently with the same PDC bit used to the drill the next interval.

For the 9 5/8-in section, the Allegro CD directional casing-while-drilling service was selected for its ability to use the directional BHAs and PDC bits to drill and case at the same time, which reduces NPT while improving drilling efficiency.

Set 20-in casing drilling record, saved 62 hours of rig time

The Allegro XCD drillable alloy casing bit drilled a total footage of 753 m in 69 hours at an ROP of 24 m/h, setting a record for section length and depth for 20-in casing drilling in Europe. After reaching TD, the high-quality wellbore condition resulted in an excellent cementing operation. In the 9 5/8-in section, the Allegro CD service achieved an ROP of 29 m/h, saving the operator 62 hours of rig time.