Case Study - Improvements to Cementing Operation and Installation of Cement Packer and Inflatable Cement Retainer for Water Shut-Off

Abstract This paper highlights the related challenges, lessons learned, and recommended best practices to improve the cementing operation and installation of cement packer and inflatable cement retainer using Coiled Tubing (CT) as conveyance during zonal isolation operations for meeting the objective of Water Shut-Off (WSO). The study was triggered by a cement overshot issue during a Production Enhancement (PE) job to reactivate Well X-1. The scope of the paper focuses on four (4) aspects - cement design, cementing operational planning, cementing operation execution, and cement verification. Well X-1, initially completed as a single gas producer from A1/A2 sand in 1997, underwent subsequent isolation of A1/A2 sand using a tubing plug and additional perforation at B1/B2 sand in 2002. A workover was performed in 2010 to replace tubing size and reperforate B1/B2 sand. However, sand production led to the well being idle in 2014. To reactivate Well X-1, a Non-Routine Production Enhancement (NR-PE) job was performed, involving a Water Shut-Off (WSO) using cement to prevent unwanted water production and later installing Thru-Tubing Gravel Pack (TTGP) as the remedial sand control. However, the job was suspended due to cement overshot during WSO operation that covered the entire H1 interval after 3 stages of cement pumping (i.e. after severe cement loss into formation during the 1st & 2nd stages of cement pumping). A Root Cause and Failure Analysis (RCFA) was conducted, where best practices and lessons learned were documented. The Post Job Analysis and Lessons Learned Report (PJALLR) revealed three (3) main issues - cementing overshot, difficulties during the setting of the Retrievable Cement Packer (RCP) and the unsuccessful setting of the Permanent Inflatable Bridge Plug Cement Retainer (PIBP-CR).