Evaluation and optimization of the well completion processes in the Keshen 13 Block

The Keshen 13 Block of the Tarim Oilfield is a gas reservoir of ultra depth, ultra high pressure and high temperature, which tends to suffer mud loss and blowout easily, it needs large-scale reservoir reconstruction, and its well completion processes are of high difficulty. The status of the well completion processes used in the high pressure gas wells of the Tarim Oilfield was summarized. Then, based on the geological conditions and engineering requirements of Keshen 13 Block, the one-stage well completion process of perforation-reconstruction-completion combination and the two-stage well completion process of perforation firstly and then reconstruction-completion combination were comparatively evaluated. It is indicated that as for the one-stage well completion process, its perforating gun cannot satisfy the temperature and pressure requirements, and it undergoes wellbore blockage, sand buried perforating gun, restricted production testing and other problems. The two-stage well completion process is suffered from incomplete mud displacement, which results in wellbore blockage and reservoir damage. In order to solve the problem of mud displacement in the two-stage well completion, the two-stage well completion process with soluble screen was studied. It is indicated that this process can satisfy the requirement of full-hole mud displacement, reservoir reconstruction and production testing while avoiding wellbore blockage and sand buried string and it is also beneficial to the later workover fishing.