Monobore Completions for Slimhole Wells

Abstract The oil and gas industry of today is vastly different from that of 20 years ago. Today 5 climate is one in which operational strategies are being subjected to a continuously-increasing number of stringent controls, imposed by both regulatory and economic constraints. In response the trends worldwide appear to have taken two directions; one concerns optimization of well production but, of fewer wells and the other places impetus on the need for new methods to improve operational efficiency of drilling and completion practices, and thus, make them more economically feasible. This paper discusses a completion concept that can support either trend. "Slimhole" and "monobore" are completion concepts that were first attempted during the 60's and 70's and have recently gained popularity because of the potential cost savings each offers. The technological advances in equipment technology and in well servicing techniques for each concept provide reasons to adopt these individually as acceptable completion practices. The fact that these recent advances have enabled the two concepts to be combined into one completion system, the combination of which can further enhance production flexibility, provides even stronger support for employing these techniques. The overview presented here will introduce the completion equipment and techniques and the benefits that will help to establish these concepts as routine completion methods. Introduction There are many definitions for the terms "slimhole" and "monobore." To simplify the scope of this paper, "monobore" is defined as a completion with a single production tubular bore size from the surface and through the producing zone; and "slimhole" is used to designate a well in which the wellbore has been drilled with the intent to minimize the hole size and subsequent tubulars.