Unlocking Brown Field Opportunities – An Operators Insights and Recommendations for Maximizing Shallow Zone Monetisation Through Rigless Cement Packers

Abstract Cement packers are used to complete shallow zones above the existing production packer using rigless techniques. Cement packers are commercially very attractive completion technique especially in offshore environment since it substitutes a rig-based workover. The operator has completed close to 30 wells using rigless cement packer technique over last 10 years. This paper documents key findings and recommendations with special focus on zone identification, well intervention and perforation techniques for cement packer applications. The Operator has been at the forefront of using rigless cement packer technique followed by thru tubing perforation in order to complete and monetize the shallow producing zones. This rigless cement packer technique however has certain inherent technical challenges and requires detailed attention to all aspects of well program. Production Enhancement team at Operator conducted detailed lookback analysis of the previous 30+ jobs done by the operator. Every step of cement packer job design and execution was reviewed in depth during this study and key findings will be discussed in the paper along with recommendations for future jobs. The lookback analysis indicated that the key challenges for a successful cement packer job were reservoir identification, cement recipe, post job sand control and perforation. The study also highlighted the increased challenges when completing a cement packer job in a dual completion and also the criticality of perforation gun testing and selection. The paper will discuss on the recommended steps and suggested workflow for all the key challenges mentioned above based on the data acquired and reviewed in the lookback study. Special focus will be on the reservoir identification and the perforation gun selection for cement packer applications. Suggested workflows for the Behind Casing Opportunities (BCO) will be discussed in detail in the paper. Perforation for cement packer cases is specially challenging which often requires orientation and small gun sizes. Since perforation design and specifications are not specifically outlined in API RP 19B hence the operator is planning detailed perforation charge testing using perforation service providers which will be first such exhaustive test program for cement packer application. The perforation testing program will be presented in the paper. In addition, learnings on well intervention, orientation, cement recipe and well intervention program will be included in the paper. Cement packer completions for shallow sands will become increasingly prevalent in future once the primary completed zones will deplete. While the cement packer technique has been utilized for a considerable duration, the absence of a comprehensive lookback analysis of cement packer jobs across numerous wells is notable. This paper is a pioneering effort that promises significant value to operators planning cost effective cement packer technique to efficiently monetize the shallow zones shallow sands.