Optimisation of technological parameters for coupled liquid CO2 fracturing-huff and puff treatment in tight oil reservoirs

Coupled liquid CO2 fracturing-huff and puff (CCFHP) treatment is combination of CO2 stimulation and CO2 EOR, aiming to maximise the productivity of tight oil reservoirs. In this work, we develop analytical procedures and methods to analyse technological parameters during CCHFP treatment. Several parameters, such as fracture length, fracture conductivity, fracture spacing, CO2 injection volume, soaking time, bottom hole flowing pressure (BHFP) are studied. Compositional numerical model is employed to simulate the flow process and interaction between CO2 and oil in reservoir. Orthogonal analysis method is then utilised to analyse the sensitivity of technological parameters and optimisation is implemented accordingly. The results show that the production rate of coupled liquid CO2 fracturing-huff and puff treatment is better than both CO2 fracturing treatment and CO2 huff and puff treatment. The research has valuable guiding significance for design and optimisation of field operation.