New Approach and Technology for CO2 Flow Monitoring and Remediation

Abstract

A novel, cost-saving approach combining rapidly-acquired CO2 flow measurements and early-alteration improves CO2 placement, leak detection, and remediation in CO2 enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects. The approach is based on field-proven technologies for monitoring CO2 flows and for controlling flows within reservoirs or remediating flows outside of reservoirs. The new low-cost monitoring technology employs reservoir flow induced micro-deformation measurements by three basic technologies—satellite-based interferometric synthetic aperture radar (InSAR), surface and downhole tiltmeters, and differential global positioning systems (GPS). These methods acquire microdeformation data in near-real-time (NRT). This data supports NRT geomechanical inversion analysis that provides 3-D reservoir flow images. Real-time temperature and pressure data from wells instrumented with sensors connected to fiberoptic cables may also be used to better characterize some CO2 flows. The new lost-cost flow control and remediation technology is derived from improvements in flowpath sealants and placement methods that can alter flows both inside and outside of reservoirs. This monitoring technology has evolved from similar methods proven in other types of secondary and tertiary recovery projects, and more recently in CCS projects, to identify reservoir flows and pinpoint abnormal ones. An example of normal CO2 flow results is presented to show how operators can calibrate flow-prediction software models and make fast decisions to apply flow enhancing methods. These methods improve CO2 sweep efficiency, increase oil production, and better utilize the reservoirs’ CO2 storage capacity. Another example shows the early identification of an abnormal flowpath location that enables timely selection of sealing methods and materials that eliminate unwanted flows from reservoirs with negligible CO2 losses. The CO2 flow control and remediation technology’s history of field-proven success is described along with recent developments that have improved both material and placement performance. Generic case histories of conventional vs. the proposed new approach are compared to show how the combination of rapidly-deployed, CO2 flow-alteration and monitoring technologies creates synergies that can improve the performance of CO2 EOR and CCS projects while reducing operating costs.