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SPE International Conference on CO2 Capture, Storage, and Utilization,
10-12 November 2010,
New Orleans, Louisiana, USA
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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 fiber-optic 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.
Introduction
When unexpected CO2 well and reservoir conditions arise, monitoring services
help operators know the severity of abnormal CO2 flows inside and adjacent to
wells, and in far-field regions inside or outside the reservoir. Remediation of
these abnormal CO2 flows to maintain well integrity and reservoir conformance
may be addressed during CO2 well operations by:
• Planning to manage the risk of abnormal CO2 flows
• Identifying potential risk scenarios
• Selecting the best risk mitigation option
• Designing and applying the selected remediation technologies
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