APPLICATION OF LATCH-IN METHOD IN SUBSEA TOP HOLE CASING CEMENTING TO ELIMINATE CEMENT SHOE TRACKS Andoko, Aribowo, Setiati, Rini, Fathadin, Taufiq
Department of Master Petroleum Engineering, Trisakti University, Jakarta, Indonesia
Abstract
Subsea oil and gas drilling has been well known for more capital intensive as compared to other offshore and even land. Since the beginning of subsea well drilling, improvement opportunities have been an ongoing subject of discussion for a more efficient and cost-effective subsea drilling operation. Subsea drilling operation is comparatively more expensive and more complicated in comparison with other offshore and land wells counterpart due to its nature being the wellhead is underwater slightly above seabed.
The decisions made during subsea well planning was primarily focused on safety, cost efficiency, and design adaptability. As the climate has received increased attention in recent years, the environment has risen to the top of the agenda for both society and authorities. As a result, the oil business must devise innovative solutions to prioritise sustainability and environmental concerns.
Subsea top-hole, conductor string setting and cementing with subsequent next casing are usually using similar method of primary cementing utilising inner string assemblies as conduit for cement placement as normally called poor boy cementing. As common practice, conventionally the method has been using a tail pipe inner string with some 40 ft of distance between the inner string and the top of the shoe that will force to leave some 20-30 feet of cement as shoe track inside the casing being cemented to ensure no contaminated (wet) cement around casing shoe.
A slight improvement is made by using a novel technology called latch-in method for the inner string to be able to completely sting in into compatible shoe (latch-in) and eliminate the cement shoe track altogether. The benefit of no shoe track while ensuring good cementation around shoe is no cement drill out required thus reducing critical path drill out of cement shoe track that can vary between 2-3 hrs to drill 20-30 ft of cement shoe track inside casing. There will cost impact due to time reduction with no drill out time, only drill out shoe which normally will take less than an hour.
