Pressure Management and Plume Control at the Devine Test Site, South Texas by Means of Brine Extraction
在盐水层二氧化碳封存中，注二氧化碳引发的压力上升是关键问题，其受多种因素影响，过高压力会增加二氧化碳泄漏风险、降低封存能力并限制项目寿命。本文设计了德克萨斯州迪瓦恩试验场霍斯顿地层盐水抽取现场试点项目进行压力管理和羽流控制，并研究用地震和示踪剂数据监测压力前沿及注入流体羽流的可能性。利用 CMG - STARS 对主动和被动压力管理系统进行模拟，探究不同抽取情景下的压力控制，还通过敏感性模拟确定了主要盐水抽取设计变量及关键压力控制参数，发现主动抽取在压力控制方面比被动抽取更有利，主动抽取与无抽取相比的压力控制百分比在 35 - 45%，被动抽取仅约 2 - 5%。
CMG 软件应用情况
本研究使用 CMG - STARS 模拟器进行所有模拟工作，模拟的是储层盐度下盐水的单相流。通过构建包含霍斯顿地层等三层垂直结构的模型，在模型中设置注入井、抽取井和观测井等条件，模拟不同情况下盐水注入和抽取过程，如注入 90 天同时抽取井以不同方式工作等场景，以及改变渗透率、层厚等参数进行敏感性模拟，以此研究盐水抽取对压力控制的影响，为压力管理策略设计提供依据。
作者单位：德克萨斯大学奥斯汀分校
Abstract
A critical issue for saline CO2 storage is build-up of pressure caused by CO2 injection. The magnitude of the pressure build-up depends on many factors, including the injection rate, static properties of the target formation, nature of the in-situ and injected fluids, and the formation boundary conditions. Maximum pressure increase is localized at the injection well; however, a pressure front diffuses into the formation, increasing pressure regionally far from the injection well. Within the context of CO2 geological storage, excessive pressure buildup is undesirable because it increases risks of CO2 plume leak into unwanted zones, reduces the storage capacity of the formation and can limit the life of a storage project.
In this study, we design a brine extraction field pilot project for pressure management and plume control at Hosston Formation in Devine Test Site in Texas. We investigated the possibility of using seismic and tracer data to monitor pressure front and injected fluids plume. Seismic surveys provide the volumetric coverage needed to understand the 3D subsurface fluid and pore pressure front movement; however, the limit of seismic detectability may be influenced by Hosston formation initial pore pressure. The range of minimum pore pressure increase needed to produce detectable P-wave and S-wave seismic velocities is investigated. Simulation study of active pressure management system (APMS) and passive pressure management system (PPMS) at the Devine Test Site is performed using CMG-STARS to demonstrate the possibility of the pressure build up control in the storage formation. The estimation of pore pressure increase from flow simulations will help us to understand if the pressure changes during brine injection and extraction can be detected using seismic response.
