Extended-Reach Drilling -- What is the Limit?

Abstract

Abstract British Petroleum has continuously been at the forefront of ERD (Extended-Reach Drilling) achievements, with its operations at Wytch Farm in Southern England, Pompano in the Gulf of Mexico, numerous fields in the North Sea and the Niakuk and Milne Point developments off the North Slope in Alaska. In order to access reserves and extend the life of mature fields, a strong demand for cost effective ERD has now materialised. As the ERD envelope has rapidly evolved during the 1990s, many operators are now reassessing field opportunities previously considered uneconomic, when an onerous capital investment in new equipment was necessary. A now common question is "Using ERD, how far can we drill using an existing rig and what is the impact of upgrading various rig components?" This paper attempts to address this question by exploring a number of recent case studies where offset field data and advanced analysis techniques are utilised. Increased emphasis is being placed on data collection and analysis, both of which are necessary in understanding critical ERD operations. With this improved learning, predicting future performance in higher step-out wells is more manageable. For future ERD campaigns it has been determined that drilling hole is not necessarily the most limiting operation in significantly extending reach. The "drilling" constraint that is now emerging is more often associated with excessive drag levels when running long casing strings or sliding drilling in high angle, high step-out wells. Most of this recent experience relates to shallow reservoirs where the highest step-out wells have been drilled. This however is where the most productive engineering advances have been made. The paper will also provide a vision of the future and highlight areas where technological breakthroughs will be required in order to drill and complete ultra-reach ERD wells of the future. P. 87