- • Maintaining tool face orientation.
• Slow sliding, or inability to slide.
• Poor hole cleaning when sliding.
• Poor hole quality from rotating motor bend.
• Borehole tortuosity and spiral.
In order to be sure that each rotary steering application made economic sense in the low-cost environment, PDO developed screening criteria. These included drilling performance, value of information, drilling enabling and production. PDO also made sure that each application has a measurable performance metric that fulfills the operator’s requirements and is acceptable to the contractor. Incentive pricing was used based on, for example, dollar per meter drilled and a ROP bonus, for a performance drilling application on a deviated sidetrack. Or dollar per meter successfully logged on a trajectory control application to enable wireline logging.
In one case history that Mr Riyami presented, RSS was used for performance drilling in a deviated sidetrack. The closest directional well to the planned sidetrack was drilled with motors in a S-shaped hole. This S-section took 42 days to drill. In the new sidetrack, a point-the-bit rotary steerable system was used to drill the S-section, which took eight days to drill from 1,500 m to 3,000 m TVD. The ROP was comparable to offset vertical wells and considerably faster than the previous directional well. Drilling torque for the vertical section beneath the S-shape was reduced significantly as well.
Additional case histories related to this presentation will be detailed in the July/August issue of Drilling Contractor.