Recent Advances and Emerging Technologies for Extended Reach Drilling

Abstract

SPE Members Abstract/Introduction Extended-Reach Drilling (ERD) is being successfully pursued by various major operators in locations world-wide. Specialized ERD equipment and operational procedures are advancing rapidly from a number of different sources. Case histories of ERD achievements and detailed analyses of specific ERD technologies are proliferating in industry literature. This paper summarizes recent advances and emerging technologies to document available systems for ERD projects and to accelerate technology transfer and development within the industry. This paper highlights recent industry ERD projects and provides specific advances in the areas of wellbore stability, drilling fluids, drilling equipment, drilling systems, and tubular design and running. Overview of Key Industry ERD Projects In spite of the publication of ERD "limits or envelopes". the limits of ERD with current technology have not yet been found. To recognize the rapid pace of "pushing back the envelope". Consider these successful ERD operations: UK Land BP Exploration has pioneered many new ERD technologies at Wytch Farm in their successful pursuit of world-record ERD achievements. BP Wytch Farm ERD involves the development of offshore oil reserves from an onshore drillsite in a scenic and environmentally sensitive Southern England location 11–31. The economic incentive was reserves development without the building of an artificial island for conventional departure wells. BP Exploration has extended achievable departures at Wytch Farm in the relatively shallow (1600m TVD) Sherwood reservoir from 4 km to nearly 7km in a period of only two years during 1993 and 1994. Well M2 was drilled to a departure of 6760m in late 1994 and Well M3 to 6818m in early 1995. Multiple world-records have been set, and reach/TVD ratios have been extended from 2.4 to 4.28. Further achievements from BP are expected. Norway Statoil and Norsk Hydro have made extraordinary progress in ERD pursuits in the Statfjord and Gullfaks fields. The Statfjord wells are drilled into reservoir at 2700m TVD. Statfjord Well C10 achieved 5km departure in 1989/1990. The first 6km departure well in the industry was achieved by Statfjord Well C3 (6.1 km) in 1991. In 1992. Well A36 achieved 5km departure in the shallower Gullfaks reservoir at 2160m TVD, resulting in a MD/TVD ratio of 2.79, among the highest at the time. In 1992/1993, Statoil's Well C2 set new world records and broke the 7km departure "barrier" for the first time in the industry. Well C2 achieved a 8.7km MD and a departure of 7.3km at the Statfjord reservoir TVD of 2700m. In 1994, Norsk Hydro's Well C26 extended these achievements further and set another new world record for well departure. Well C26 achieved 9.3km MD and a departure of 7.85km at 2770m TVD. Statoil is planning wells with measured depths of over 10km and departures on the order of 9km. Research also continues on wells with departures of 10km in the Statfjord reservoir UK Offshore Amoco UK has been among the leaders with ERD in the Arbroath and Hutton fields. Following a failed ERD attempt in 1991. Well Tl9 achieved an MD of 5.8km and a departure of 4.6km in the reservoir at 2600m in 1992. That achievement was extended with the SEER-Tl2 well which achieved an MD of 7.5km and a departure of 6.4km in 1993. Other operators in the UK sector have also drilled substantial ERD wells. Shell Expro set records at the time with the Cormorant A-l3 well with a departure of 4.7km in 1988. More recently. Shell's Tern A-5 achieved 5km departure at 2770m TVD, while their Galleon Well PN02 that achieved a 5.7km MD at a TVD of 2500m for a MD/TVD ratio of 2.3. Mobil drilled Excalibur Well ES that achieved a 6.9km MD at a TVD of 2660m, for a MD/TVD ratio of 2.60. P. 291