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.

Integrated Study on Carbon Dioxide Geological Sequestration and Gas Injection Huff-n-Puff to Enhance Shale Oil Recovery

“…When carbon dioxide enters the matrix, the volume of crude oil in the matrix expands, the viscosity decreases, and the interfacial tension decreases. As the oil expands, the pressure in the matrix rises, creating a new pressure gradient that allows the oil in the matrix to be pumped out through microfractures [16]. In the development of CO2 huff-n-puff EOR, many scholars have proved the effectiveness of this method through a large number of experimental studies.…”