The Boris Field Development - Short Cycle Time and High Well Productivity

Abstract BHP Billiton has completed the development of the Boris field, located in Green Canyon block 282. The two development projects were executed with short cycle times, and the wells have very high productivity. This paper reviews both projects, including subsurface issues, well completions, project execution, production issues, and lessons learned. BHP Billiton has completed the development of the Boris field, located in Green Canyon block 282. The two development projects were executed with short cycle times, and the wells have very high productivity. This paper reviews both projects, including subsurface issues, well completions, project execution, production issues, and lessons learned. Introduction The Boris field is located in Green Canyon block 282, approximately 170 miles SSW of New Orleans, and approximately five miles southeast of the Typhoon field located in Green Canyon 236/237. The Boris field is operated by BHP Billiton with a 50% interest. Other partners include ChevronTexaco and Noble Energy, Inc., each with a 25% interest. The Boris field was developed as a two-well subsea tieback to the Typhoon production facility. Typhoon is owned by ChevronTexaco and BHP Billiton, each with a 50% interest, and operated by ChevronTexaco. Production from the 282 #1 well in the Boris south reservoir began on February 3, 2003. The 282 #2 well in the Boris north reservoir had first oil seven months later on September 17, 2003. The finding and development cost of the Boris field, including drilling of both exploration wells, totaled about $140 million. The project has produced approximately 4.3 MMBO and 6.5 BCF of gas as of December 31, 2003. This project was an important milestone for BHP Billiton because it was the first operated deepwater project for the company, and it was brought onstream safely, quickly, and efficiently. Boris South - Exploration (GC 282 #1) The first Boris exploration well was driven by the Typhoon near-field strategy of low-risk, high-margin reserves with short cycle times that utilize existing infrastructure. The 282 #1 well was spud in August 2001, only one month after the Typhoon facility began production. The exploration plan called for an initial penetration of the seismic amplitude followed by a short sidetrack to a production location. The sea-floor location of the well was chosen with development in mind. A sea-floor escarpment exists between the amplitude location and the Typhoon facility that would have been risky to cross with a flowline. A surface location west of the amplitude was chosen to mitigate this risk. This caused a long-reach deviated well trajectory with slightly higher risk and expense. After a successful initial penetration, the updip sidetrack experienced mechanical problems, requiring a bypass. The bypass reached the drilling objective but pressure data indicated that it was in a lower pressure regime than the original penetration, which was interpreted as possible compartmentalization. It was later demonstrated that the decreased reservoir pressure was caused by hydraulic communication with production from the Typhoon 237 #2 well producing from a reservoir that shares a common aquifer with the Boris reservoirs.