Advances in Single-diameter Well Technology: The Next Step to Cost-Effective Optimization
From inception, solid expandable tubular technology has been touted as a game-changing technology. The logical end result of the technology, a single-diameter well, consists of a casing string with the same diameter at the top of the well as at total depth (TD). However, many drilling operators were reluctant to embrace even the basic solid expandable tubular concept without any track record, coupled with what they saw as the inherent risks. Now, after five years of commercial installations, solid expandable tubular technology has proven to be a viable and economically feasible alternative to conventional drilling technology. In the majority of these installations, solid expandable tubulars have been deployed as a contingency to save a well when conventional technology failed. While this type of application is appropriate, operators do not reap the full advantage of all the benefits solid expandable tubular technology offers when integrated as part of the well plan. A crucial step in the acceptance of expandable tubulars as a viable well construction method is to plan the system into the initial well design. In order for the tubulars to be planned into the original well design, operators must understand the compelling economic business cases for the application as well as accept the level of risk. The proven track record has helped mitigate the risk level for many operators, who are now focusing on the value proposition this technology provides. Operators must be comfortable with solid expandable technology in order to make the necessary leap of faith to the single-diameter well. This paper will present the progress of monobore technology up to the present. It will discuss the stages achieved and those that still must be overcome to make this technology feasible. The paper will demonstrate that with solid expandable tubular and monobore technology, operators in general and deepwater operators in particular, will be able to maximize reservoir potential and lower drilling costs when using this value-added technology.