CO2 增能压裂不同生产阶段裂缝内 CO2 滞留碳埋存.

Objective At present, the carbon storage technology mainly consists of geological structure storage, residual gas storage, dissolution storage and mineral storage. With the application of CO2 fracturing related technologies, It is necessary to carry out in-depth research on the mechanism and main controlling factors of CO2 storage after energized fracturing. Methods According to the factors affecting the pore space and conductivity in fractures, the optimal values of the influence of different factors on fracture retention carbon storage were selected by proppant (quartz sand and ceramsite) under different sand spreading concentrations (5.0 kg/m², 7.5 kg/m² and 10.0 kg/m²) and the effects of different factors on fracture retention carbon storage were analyzed by orthogonal experimental method. Results CO2 storage is mainly in the supercritical state; the storage rate of CO2 is more than 80% when in the supercritical state. The storage rate decreases rapidly as the formation pressure continues to decline, and the storage rate is only about 40% when the pressure drops to 6 MPa. The factors affecting the storage rate include closing pressure, flowback rate, proppant type, and sand spreading concentration, and the influencing order from large to small is closing pressure > flowback rate > proppant type > sand spreading concentration. The main controlling factor is the closing pressure, and the storage rate gradually decreases with the increase of the closing pressure. Conclusion The problem of unclear understanding of CO2 storage carbon in CO2 energized fracturing fractures was solved, and the influence of four fracturing fracture-related parameters on CO2 storage was clarified. While in the design of CO2 energized fracturing, CO2 storage can be predicted based on experimental results. [ABSTRACT FROM AUTHOR]