A study of the potential of field-scale of CO2 geological storage and enhanced water recovery in the eastern Junggar area of Xinjiang

Abstract

CO2 geological storage combined with saline recovery (CO2-EWR) is considered to be one of the effective storage methods. Taking the lead in carrying out CO2-EWR technology in the eastern Junggar of Xinjiang can achieve CO2 emission reduction and mean while produce saline water, which can alleviate the local water resources shortage problem to a certain extent, and obtain dual benefits of environment and economy. Previous research mainly focused on generalized models, and the support of engineering practices is lacking. Based on the evaluation results of the suitability of CO2 source - sink matching in the eastern Junggar Basin and the geological data of the first CO2-EWR field pilot test site in China, a 3D heterogeneous model of the Xishanyao Formation of the CO2-EWR test site in the eastern Junggar Basin is constructed to study the potential of the CO2-EWR technology. The results show that the the oretical storage capacity of CO2 at the test site is 1.72 × 106 (P50) tons, and the dynamic storage capacity is 2.14 × 106 tons. When the CO2-EWR technology is adopted, the CO2 dynamic storage capacity can reach 11.18 × 106 tons, which is 5.22 times the CO2 geological storage only, and may increase the production of the saline water resources by 10.17 × 106 tons with a mass ratio of 1 to 0.91 of CO2 sweeping out saline water. Meanwhile, the CO2-EWR technology can effectively slow down the accumulation of reservoir pressure caused by the massive injection of CO2, improve the efficiency of CO2 storage, and increase the saline water production potential. This study can provide theoretical basis and technical support for the implementation of large-scale CO2 geological storage combined with deep saline water production project in the eastern Junggar of Xinjiang.

Keywords

• deep saline aquifers
• co2-ewr
• field-scale
• potential assessment
• junggar basin