Lesson Learned: Well Logging Analysis to Interpret Shallow Connection Between Two Wells in Dieng Geothermal Field, Indonesia

Abstract

Loss of annular integrity in a well can create a loss of zonal isolation, which significantly impairs the productive capability and efficiency of geothermal well. Effective remedial action must be based on a clear understanding of the underlying causes. Without this information, repair or control is at best a matter of informed guesswork or trial-and-error. HCE-A and HCE-C are two production wells on the same pad in Dieng Geothermal Field, Indonesia. In early 2019, both wells were offline with 0 psig of WHP (Well Head Pressure). During the production period, HCE-A WHP is mimicking the HCE-C WHP. This response continues even though HCE-C was down because of casing integrity issues. Casing leakage was indicated by the chemistry analysis of a fluid sample from HCE-C. The relationship between both wells shows that the connection was not located in feed zones area but in shallow depth. To get a better understanding, an integrated investigation was carried out, starting from MTD (Magnetic Thickness Detection) to PTS (Pressure/Temperature/Spinner) logging in shut-in, injection, and transient conditions. In conclusion, the results were satisfactory as based on the integrated investigation, the leakage location which connects both wells in shallow depth can be determined. These investigation results play a significant role in creating an effective and efficient remediation program in both wells.