Horizontal Well Performance at Prudhoe Bay

Abstract

ABSTRACT The first horizontal wells in the Prudhoe Bay Unit were drilled In the central gravity drainage area to increase standoff between the wellbore and the gas cap for improved recovery and increased production rates. Subsequent applications of horizontal wells have included producers in the peripheral area of the field and adjacent waterflood regions, drainholes and gas injectors. Innovative and cost effective horizontal drilling and completion techniques were developed. Horizontal wells have been drilled at angles up to 98 degrees and for lengths exceeding 2100′. There are currently twenty-seven horizontal wells, including two gas injectors, In the Prudhoe Bay Unit with significant opportunity for further development utilizing horizontal well technology. The performance of the Prudhoe Bay Unit horizontal wells have been evaluated after 1 – 5 years of production to determine the incremental benefits for future justification of the additional costs associated with drilling and completing horizontal wells in comparison to conventional completions. This paper describes the overall performance of horizontal wells In the Western Operating Area of the Prudhoe Bay Unit Including surveillance and wellwork achievements, drilling and completion technology developed and the reservoir modelling and analytical efforts to date. The current and future strategies of horizontal well applications are also addressed.