In today's oil and gas industry, reducing drilling time and cost has become more and more important as wells have been drilled deeper and costs have risen. This paper will describe a case study of a well drilled in the Main Pass area of the Gulf of Mexico for a major operator. In this job, in order to eliminate a trip and significantly reduced costs, it was required to rotate a bottomhole assembly (BHA), including an expandable reamer, across a whipstock.
This well contained several unusual challenges that will be described, including a shallow kick off and a subsequent extended-hole section to reach a proposed total depth (TD) in excess of 10,000 ft, drilling through sand and shale.
The paper will describe the team process, coordination and communication required between the operator and service companies to make this unique job successful. Offsets will be compared with respect to drilling dysfunction, vibrations, time, costs, and the like.
To reduce cost and non-productive time (NPT), it was decided to forgo drilling a long rathole out of the whipstock and proceed immediately with reaming on the next trip in. This approach required rotating the closed reamer across the whipstock, necessitating a series of analyses to limit the risk while performing this unusual feat. Extra trips were eliminated by using innovative well planning, procuring downhole tools with reputation of toughness and reliability, and finally requiring excellent cooperation between all involved parties. This job was confirmed to have saved the operator 29 hours of rig time and in excess of $250,000, while reducing the drilling plan by two days.