Analyzing Advanced Techniques for Stage Isolation in Multi-Stage Hydraulic Fracturing

Abstract Modern horizontal wells typically use "plug and perf" completions requiring temporary plugs, which must be milled out after fracturing. This paper reviews alternative designs, especially wireline deployed discrete plugging devices to replace traditional frac plugs and improve stage isolation during completion. Proppant tracing with spectral gamma ray logging can be utilized as a tool for near wellbore proppant placement evaluation as well as stage-to-stage isolation evaluation. The technique involves pumping a unique tracer (or multiple tracers for temporal evaluation) in a fracturing treatment stage and logging the stage after the treatment is completed. Case studies are presented as part of this paper showing near wellbore treatment isolation. The first case study is the base case of a plug and perf design showing excellent stage isolation when the plugs performed as designed and isolation failure when they did not. The second case study is an advanced sliding sleeve system. The final case study and the focus of the remainder of the study will show isolation failure and effective isolation from wells utilizing the discrete plugging device. Data will be presented in aggregate, comparing plugless completion to plug and perf for stage-to-stage evaluation as well as near wellbore proppant coverage.