Field Wide Intervention-Less Reservoir Pressure Data Acquisition through the Application of Echometer – A Case Study

Abstract

This paper aims to present a field-wide case study that explores the use of Echometer survey as an alternative method for acquiring static reservoir pressure data. In Field X, located in the East Malaysia Region, conventional static gradient surveys (SGS) were typically deployed to measure the static reservoir pressure. However, conducting SGS in Field X posed challenges related to balancing data acquisition with production enhancement activities, limited operation windows availability, and minimizing production deferment. The Echometer application addresses these challenges by offering non-invasive data acquisition with minimal equipment requirements. The Echometer application employs a non-invasive approach by shooting acoustic waves into the well. As these waves travel downward and encounter any abrupt changes in the well, some of the waves are reflected towards the surface. By analyzing these reflections, which indicate disturbances to the acoustic waves, the fluid level inside the tubing can be determined. By combining this information with shut-in tubing head pressure (SITHP) and fluid gradient measurements, the static reservoir pressure can be estimated. In Field X, 17 surveys targeting 14 different reservoirs were conducted using the Echometer, and the results were compared with available permanent downhole gauge (PDG) data, reservoir pressure trends, and the latest SGS conducted to assess the reliability of the application. The Echometer campaign has demonstrated its effectiveness and reliability in determining static reservoir pressure. It can be considered as an alternative to SGS in fields with limited wireline windows due to its minimal equipment requirements, minimal production deferment, and absence of invasive well intervention. A presentation and discussion on the successful outcomes, limitations, best practices, and lessons learned from the Echometer campaign aim to contribute to the repertoire of production surveillance tools in the oil and gas industry by providing alternatives to conventional SGS for data acquisition.