Case History of the Removal of a Hydrate Plug Formed During Deep Water Well Testing

Abstract

Case History of the Removal of a Hydrate Plug Formed During Deep Water Well Testing E. M. Reyna; E. M. Reyna Conoco U.K. LTD Search for other works by this author on: This Site Google Scholar S. R. Stewart S. R. Stewart Halliburton U. K. LTD Search for other works by this author on: This Site Google Scholar Paper presented at the SPE/IADC Drilling Conference, Amsterdam, Netherlands, February 2001. Paper Number: SPE-67746-MS https://doi.org/10.2118/67746-MS Published: February 27 2001 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Get Permissions Search Site Citation Reyna, E. M., and S. R. Stewart. "Case History of the Removal of a Hydrate Plug Formed During Deep Water Well Testing." Paper presented at the SPE/IADC Drilling Conference, Amsterdam, Netherlands, February 2001. doi: https://doi.org/10.2118/67746-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE/IADC Drilling Conference and Exhibition Search Advanced Search Abstract The potential for gas hydrate production is always present in deep water operations. The negative impact of gas hydrate formation on both drilling and completions activity in deep water has been documented previously1,2 . Another speciality operation that holds equal hazardous potential is drill stem testing in deep water. This paper describes the cause and solution to a hydrate plug that formed during a deepwater well test operation off the UK Continental Shelf, West of Shetlands. During well test operations in a water depth of 2750', an 800' hydrate plug formed in the string inside the riser above the mud line, prohibiting communication with the well below the SSTT. Diagnostic tests were carried out to determine the source of the blockage, and two potential culprits were initially identified - paraffin or hydrates. Coiled Tubing was mobilised to attempt removal using a heated glycol / brine solution. After several diagnostic operations, a coiled tubing jetting assembly and finally a mill and mud motor was successful in safely removing the hydrate blockage.This paper will discuss: ➢How hydrate formation was masked by other aspects of the well test➢The technical and operational issues considered while developing the procedure for removal of the hydrate plug➢The outline of the final procedure➢The result of the execution➢The lessons learned Keywords: circulation, water production, coiled tubing, landing string, case history, paraffin, upstream oil & gas, production monitoring, assembly, completion installation and operations Subjects: Well & Reservoir Surveillance and Monitoring, Flow Assurance, Formation Evaluation & Management, Drillstem/well testing, Completion Installation and Operations Copyright 2001, SPE/IADC Drilling Conference You can access this article if you purchase or spend a download.