致密油藏研究的重点是根据岩石和流体的性质，选择合适的开发方式。致密油层为超低渗透地层（小于0.1 mD），水平井和水力压裂是主要开发方法。但在应用这些方法后，储层中仍有大量剩余油，需要进一步提高采收率，我们选择CO2吞吐方式提高采收率。本文以巴肯油层为基础案例，研究低成本条件下提高石油采收率的参数，如储层渗透率、每段裂缝数、CO2注入速度、CO2吞吐周期数、CO2注入时间和裂缝渗透率等。
Simulation Study of CO2 Injection in Tight Oil Reservoirs
Abstract
The exploitation of Tight oil reservoirs has become a topic of interest to many searchers; the choice of methods and techniques to use, depending on the characteristics of the fluids in place is the main focused point for this purpose. Tight oil formation is formation with an ultra-low permeability (less than 0.1 mD); Horizontal well and hydraulic fracturing were identified by many searchers as the main methods to exploit this kind of reservoir. However, some new knowledge about the improvement of the oil recovery helped us to understand that there is still a lot of remaining oil in the reservoir after applying these methods: we chose CO2 huff-n-puff process to enhance the oil recovery. In this paper, we used The Bakken oil formation study as our base case. Our work is focused on parameters that can improve oil recovery without spending a high cost. We noticed that some parameters such as reservoir permeability, number of fracture per stage, CO2 injection rate, number of CO2 huff-n-puff cycle, CO2 injection time and fracture permeability can be key parameters for the improvement of the oil recovery.
Keywords: Tight oil reservoirs; CO2 injection; Hydraulic fracturing; Simulation model
