Drilling with Production Liner reduces AFEs per well, brings to early production in Urmanskoye field onshore Russia

Abstract

As an industry segment, drilling with casing and liner is still very much in its infancy. However, a few "early adopters" have been successfully extending the operational envelope and discovering new applications. The fundamental value of drilling with casing lies in improving drilling efficiency by eliminating flat spots in the drilling curve. It also has the capability of extending open hole sections to reach deeper casing points with smaller diameters, thus eliminating contingency intermediate strings. The implications for exploration and production industry are significant. Currently, there are two basic methods of drilling with casing divided as follows: Rotating the casing at surface to transmit torque to the drilling BHA, or having a retrievable BHA latched inside the casing that incorporates a motor that drives a conventional bit and underreamer. Both systems, though operational and technically sound, still have many technical issues to overcome concerning all aspects of well planning to operations on the rig floor. This paper will focus on drilling with liner by rotating the casing without Top Drive. The paper will highlight the significant lessons learned from these experiences. This emerging technology is considered '"game--changing" and is seen as complementing the expandable and underbalanced technologies which promise to revolutionize well construction. IntroductionOperators have drilled with liner in a number of areas for many years. The recent resurgence of the technology and significant developments in technology have resulted in a renewed industry interest in the technology of drilling with casing. One of the key factors leading operators to this technology is the removal of time from the drilling curve. An industry term, "nonproductive time," currently is used to describe problem time, and time associated with tool failures and inefficiencies. The procedures for rotary drilling with casing are relatively simple, and involve little extra equipment that is not normally present on a typical rig. Compared to a traditional drilling BHA, should be simple, because it is left in the ground. When TD is reached and circulating bottoms--up, cementing can begin immediately, since a float collar is present in the string throughout the drilling operation. To allow drilling with casing, a number of technologies had to be developed to enable safe and efficient and problem free operations.