Application of a Transient Near-Wellbore / Reservoir Simulator for Complex Completions Design

Abstract

Well completion operations in perforating, sand-control, stimulation, and flow management are often transient in nature, thereby making it a challenge to understand the complex physical processes that affect a safe deployment or a robust optimization of completion hardware. Historically, steady-state methods have been used to predict dynamic completion events. These methods can lead to inaccurate analysis and add risk to the decision-making process. An integrated, transient simulation approach is therefore required to model, predict, optimize and most importantly ensure a safe completion operation. In this work, we present the application of fully transient, multi-phase flow simulation software that simulates dynamic downhole completion scenarios. The computational framework of the software incorporates a coupled wellbore-perforation-reservoir model, with differentiating algorithms for shock-capturing hydrodynamic solvers, robust thermodynamic closure, advanced fluid dynamics and more importantly, significantly faster turnaround simulation times to enable quick pre-job modeling iterations. The software has been extensively used for designing and optimizing perforating jobs, but recently, the applicability of the software has been demonstrated for transient completion scenarios beyond perforating. Several application examples are presented in this study, whereby the computational software has been successfully used to predict and drive critical decisions relating to either novel completion technologies or safe deployment of completion systems. Case histories pertaining to dropped tools, downhole valves (effects of water hammer/shut-in), next-generation completion systems (fully conformable sand management systems), and safety investigation of post-perforating, completion practices, and propellant-assisted stimulation systems are comprehensively discussed in this paper. Results and data analysis including modeled pressure surge, loading on downhole equipment, transient fluid physics, history-matching and most importantly, the insight into dynamic interaction between the wellbore and formation are presented in this study. This study clearly demonstrates the importance of a transient, fully coupled simulator to predict dynamic completion scenarios as well as ensure flawless execution of next-generation completion systems. This robust simulation platform, when integrated with production calculations, also provides the scope to better predict and maximize productivity.