Active Reservoir Pressure Management with Guidance and Surveillance by Distributed Fiber-optic Strain Sensing

Abstract

CO2 injection and storage in aquifers can cause pore pressure build up and deformation of the aquifer-caprock system due to extra-fluid accumulation. Active reservoir pressure management, a concept that using brine production before or during CO2 injection to reduce reservoir pressure build up, has been suggested to avoid potential risks posed by geomechanical deformation during large-scale CO2 injection [1], [2]. Sedimentary formations usually develop heterogeneities in fluid properties and mechanical properties. When conducting CO2 injection or brine production, acquiring the in-situ information of pore pressure and fluid distribution and rock deformation would be much helpful for the project operating. In this presentation, we propose to give guidance and surveillance of the CO2 injection and brine production operations in real time using a distributed fiber optic strain sensing (DFOSS) system. We show the field and lab studies and numerical simulation results to demonstrate the feasibility and the advantages when using DFOSS for pressure management in a storage reservoir. Existing difficulties when using DFOSS are also presented.