Volume 31: Clean Energy Technologies towards Carbon Neutrality

Exploration Experiment of Development Method After Depletion of Tight Oil Hao Chen, Haizeng Yu, Chenghao Xu, Yiqi Zhang, Mingsheng Zuo, Yi Wu

Abstract

With the development of Carbon Capture, Utilization and Storage (CCUS) technology, CO2 injection to improve tight oil recovery has become a new hot spot in the field of tight oil development. At present, horizontal well fracturing, CO2 huff and puff and other technical methods to develop tight oil are not ideal, so it is particularly important to explore new methods to improve tight oil development. In this paper, reservoir cores were selected from a tight oil reservoir in Xinjiang, and the self-developed experimental device of simultaneous well and asynchronous well huff and puff was used to simulate the development process of tight oil, CO2 injection and asynchronous huff and puff and development process under different recovery pressures and production pressures, and to evaluate the displacement characteristics and development effects of asynchronous huff and puff and development process under different CO2 injection. The research shows that the integrated experiment of “same well and different well asynchronous” can better simulate the seepage characteristics and development characteristics of single well and different well stimulation after depletion development. Compared with conventional single well huff and puff method, CO2-injection asynchronous huff and puff can increase recovery by 20%-40%. The key to achieving better development results is to establish a circulating “displacement-soaking-displacement” synergistic system of different wells through pressure recovery, soaking and production process alternately between different wells. The oil transportation distance becomes smaller, the oil saturation field is constantly redistributed, and the diffusion and sweep range of CO2 is expanded. With the increase of pressure difference between “recovery and production”, the harvest effect was significantly improved. The development process can effectively avoid the CO2 backflow process, improve the CO2 utilization rate, and realize the effective storage of CO2.

Keywords Carbon Capture Utilization and Storage, Tight oil, Asynchronous huff and huff