Real-time pressure measurements ensure understanding and monitoring of faults and reservoir containment in geological storage of CO2

Significance 

Technically, CO2 injection into geological formations is quite similar to the oil field production operations. One of the main differences in the two is that the latter leads to continuous pressure decline (depletion) or pressure maintenance (by injection), while as the former (CO2 injection) normally causes reservoir pressure build-up, maybe beyond the level earlier experienced by the geological structure. Basically, this has potential to cause fault reactivation and leakage out of the target formation. Ideally, comprehending the flow barriers in a saline aquifer evaluated for geological storage of carbon dioxide is the key point for decision making and designing injection operations. This may be achieved via combining time-lapse seismic and pressure monitoring.

It has been established that the pressure data obtained in real-time during well testing and main phase of injection with installation of Permanent Downhole Gauges (PDG) may be utilized to characterize and monitor reservoir boundary conditions. Here, Pressure Transient Analysis (PTA) can be employed as interpretation tool. Regardless, several vital questions still linger unanswered mainly relating to leakage detection and the maximum allowable volume that can be injected- among others. Therefore, further research is necessitated. On this account, researchers from the NORCE – Norwegian Research Centre: Dr. Anton Shchipanov, Mr. Lars Kollbotn and Dr. Roman Berenblyum proposed to study the case of faults acting as flow barriers including scenarios of sealing and leaking faults using the history of CO2 injection into the Tubåen formation of the Snøhvit field as testing data set. Their work is currently published in the research journal, International Journal of Greenhouse Gas Control.

In their approach, the researchers first addressed the general questions on applicability of PTA for CO2 injection, related to capabilities and limitations of single-phase flow models. Next, the team suggested and tested approximate approaches to improve the capabilities of such models to deal with CO2 injection cases (brine replica). Finally, an integrated workflow for characterizing and monitoring flow barriers in geological storage projects was proposed.

The authors confirmed the value of real-time well pressure surveillance with PDG installed in injection wells. The team also reported that estimating changes in already observed boundaries for a longer history may be affected by new boundaries ought to be seen; which impacts to overall pressure build-up. Altogether, they reported that a real-time update of CO2 injection forecast is needed for long-term injection where pressure diffused to distant areas of the reservoir meeting new flow barriers or active boundaries.

In summary, the study by NORCE scientists demonstrated a basis for integrated technology for characterizing and further monitoring of reservoir boundaries and flow barriers using permanent pressure measurements in injection wells. The objective of the study was to understand how Pressure Transient Analysis could be successfully applied in CO2 storage projects, where CO2 plume has an impact on pressure transient response. Overall, in a statement to Advances in Engineering, Dr. Anton Shchipanov explained that the proposed technology offered an early detection of leakage based on active injection well monitoring, thereby making it one of the best candidates for real-time monitoring and early warning of leakage initiation.

Analysis of real-time pressure measurements ensures understanding and monitoring of faults and reservoir containment in geological storage of CO2 - Advances in Engineering
Time-lapse seismic monitoring
Analysis of real-time pressure measurements ensures understanding and monitoring of faults and reservoir containment in geological storage of CO2 - Advances in Engineering
Time-lapse pressure monitoring
Analysis of real-time pressure measurements ensures understanding and monitoring of faults and reservoir containment in geological storage of CO2 - Advances in Engineering
Impact of different effects related to CO2 injection on long-term injection in faulted reservoir
Analysis of real-time pressure measurements ensures understanding and monitoring of faults and reservoir containment in geological storage of CO2 - Advances in Engineering
The CO2 effects in pressure transient responses
Analysis of real-time pressure measurements ensures understanding and monitoring of faults and reservoir containment in geological storage of CO2 - Advances in Engineering
Monitoring of CO2 leakage from target formation: long-term effect
Analysis of real-time pressure measurements ensures understanding and monitoring of faults and reservoir containment in geological storage of CO2 - Advances in Engineering
Monitoring of CO2 leakage: detection from pressure transient analysis

About the author

Dr. Anton Shchipanov is a senior researcher at NORCE (Norwegian Research Centre) and associate professor (adjunct) at the University of Stavanger, Norway. He received his M.Sc. degree in applied mathematics and Ph.D. degree in physics and mathematics from the Perm State University, Russia. Dr. Shchipanov has coordinated R&D and industry-oriented projects in Norway and has been involved in large-scale projects with national and international industrial and public funding. He serves as a reviewer for Journal of Petroleum Science and Engineering and International Journal of Greenhouse Gas Control.

His research interests include reservoir characterization and simulation, pressure transient and well performance analyses, naturally and induced fractured and faulted reservoirs, geomechanics, improved oil recovery, carbon dioxide utilization and storage and data science applications in the areas above.

About the author

Lars Kollbotn is a senior advisor at NORCE (Norwegian Research Centre). He holds a Master of Science degree in petroleum engineering from the Rogaland Regional College (now University of Stavanger). He started his career as a reservoir engineer with the Norwegian Petroleum Directorate in 1976. In 1980 he joined Exxon where he worked until 1986. From 1986 to 1996 he was employed by Fina/Petrofina where his was mainly engaged in reservoir engineering activities related to the development of the chalk reservoirs in Ekofisk region. Since 1996 he has worked as a petroleum engineering consultant, mainly concentrating on reservoir engineering related disciplines.

He joined IRIS (International Research Institute of Stavanger, now NORCE) in 2003 and has since then contributed to many IOR/EOR research projects in addition to consultancy activity. His main attention has been reservoir modelling and related activity, particularly around CO2 utilization and storage.

About the author

Dr. Roman Berenblyum leads subsurface characterization, simulation and geomatics group at NORCE Energy. Roman has a PhD from Technical University in Denmark from 2004. Roman has coordinated various national and international research and industrial projects.

He served as a member of technical committee on a number of Society of Petroleum Engineers (SPE) and European Association of Geoscientists and Engineers (EAGE) conferences and workshops. Roman represents NORCE in CO2GeoNet – European Network of excellence on geological carbon storage and is currently chairing networks Executive Committee. Dr. Berenblyum research interests are within carbon dioxide utilization and storage (CCUS), establishing business cases for first of a kind CCUS projects, Enhanced oil Recovery (EOR), subsurface chemistry and fluid flow.

Reference

A.A. Shchipanov, L. Kollbotn, R. Berenblyum. Characterization and monitoring of reservoir flow barriers from pressure transient analysis for CO2 injection in saline aquifers. International Journal of Greenhouse Gas Control, volume 91 (2019) 102842.

Go To International Journal of Greenhouse Gas Control

Check Also

A high-precision visual tracing method of variable boresight for robot guidance - Advances in Engineering

A high-precision visual tracing method of variable boresight for robot guidance