An Overview of Geological CO2 Sequestration in Oil and Gas Reservoirs

Abstract

A tremendous amount of fossil fuel is utilized to meet the rising trend in the world’s energy demand, leading to the rising level of CO2 in the atmosphere and ultimately contributing to the greenhouse effect. Numerous CO2 mitigation strategies have been used to reverse this upward trend since large-scale decarbonization is still impractical. For multiple reasons, one of the optimal and available solutions is the usage of old depleted oil and gas reservoirs as objects for prospective CO2 utilization. The methods used in CO2 underground storage are similar to those used in oil exploration and production. However, the process of CO2 storage requires detailed studies conducted experimentally and numerically. The main goal of this paper is to present an overview of the existing laboratory studies, engineering and modeling practices, and sample case studies related to the CCS in oil and gas reservoirs. The paper covers geological CO2 storage technologies and discusses knowledge gaps and potential problems. We attempt to define the key control parameters and propose best practices in published experimental and numerical studies. Analysis of laboratory experiments shows the applicability of the selected reservoirs focusing on trapping mechanisms specific to oil and gas reservoirs only. The current work reports risk control and existing approaches to numerical modeling of CO2 storage. We also provide updates on completed and ongoing CCS in oil and gas reservoir field projects and pilots worldwide.

Tight and Shale Oil Exploration: A Review of the Global Experience and a Case of West Siberia

“…At the same time, adsorption on the pore surface is a primary physical trapping mechanism for shale and tight reservoirs. Thus, the CO 2 storage capacity of shales largely depends on their geochemical and mineral composition; the amount of clay minerals and kerogen, which are the main adsorption sites for CO 2 ; and pore size distribution [85].…”

“…Mineral matrix and pore size alteration together lead to great changes in geomechanical properties, e.g., significant reduction of Young's modulus [92,93] or Brazilian splitting strength [94], which makes geomechanics one of the most important parameters while planning any CO 2 projects in shales or any other reservoirs. Higher temperature and pressure conditions of the reservoir also influence the level of changes in the mineral matrix and pore size, hence, geomechanical properties [85].…”

Application and Research Progress of CO2 Stimulation Technology in Unconventional Oil and Gas Reservoirs: A Review and Prospect

“…CO 2 reacts with water in formations, thereby forming carbonic acid . Carbonic acid reacts with some metal cations in formation under acidic conditions, thereby forming carbonate precipitation. ,, Therefore, it can be stored forever. Figure shows the different storage mechanisms of CO 2 at different stages in saline aquifers.…”

“…Thus, they are abandoned, but they can still create value. These reservoirs can be used to store CO 2 as a result of the good sealing of reservoirs. , The storage is shown in Figure . Injecting CO 2 into gas reservoirs can not only improve their recovery rate but also protect the environment by reducing its emissions.…”

CO2 mineralization process in basalt rocks: study case, Serra Geral Formation, Paraná sedimentary Basin, São Paulo state

“…Underground geological formations are used to storage CO2 due to their wide range of geochemical and geomechanical properties. Depleted hydrocarbon reservoirs, saline aquifers, coal seams and shale formations are the most popular geological sites for storage because they are already characterized and proved (Michael et al, 2010;Temizel et al, 2016;Askarova et al, 2023). Composition and state of the CO2 fluid injection along injection depth is going to depend on the reservoir geological setting.…”