Largest Liner Hanger Ever Installed Worldwide

Abstract

Abstract Some gas wells casing design call for running and cementing intermediate 18 5/8" casing string to cover weak formations (low pressure/losses) including hydrocarbon bearing formations. Some gas wells drilled in the offshore Arabian fields developed sustained Casing-Casing Annular (CCA) pressure problems, emanating from poor cement bond of the intermediate casings, especially the 18-5/8" x 24" casing annulus. This paper will examine the source of the problems, primary solutions, and the remedy for the problems. Primary cement is the first barrier to prevent sustained CCA pressure problems; from drilling through the production lifecycle of any well. Most of the wells experienced losses while drilling or cementing the intermediate casing; the current practice is to enhance the chances of a good cement job by installing an external inflatable packer with a circulation port (DV). This device splits the cement job into two stages and enables the second stage cement return to surface. In some completed gas wells, DV and cement barrier failure were recorded, which subsequently resulted in CCA pressure development. A solution was conceived to replace the 18-5/8" casing DV stage tool with a more reliable liner hanger (LH), in the most critical casing annulus CCA3 (18-5/8" x 24"), which has a higher risk of CCA development due to mobile hydrocarbon bearing formations covered behind the 18-5/8" casing. CCA3 pressure was reported in some wells. The shallow intervals were drilled, cased, and cemented, utilizing enhanced cementing practices and a DV tool in a 2-stage cement job. The LH alternative offers a good solution, but no technology was available worldwide to run the 18 5/8" liner and set inside 24" 201# casing, to avoid CCA pressure in this particular annulus size. The operating company collaborated with the lLH provider to develop the world's biggest LH, with metal-to-metal seal in the hanger and rubber seal barriers in the tie-back. The LH equipment was manufactured over a period of 6 months, deployed, and successfully field tested in five wells with no CCA3 pressure reported to date. The results of this LH installation will be discussed using case histories of recently drilled wells in the field, and compare results with some previous wells. For critical high rate gas wells with associated high construction cost, any technology applied to enhance well integrity, such as installation of the 18-5/8" LH, is considered an absolute necessity by the operator.