Affiliation:
1. Key Laboratory of Petroleum Engineering, Research Institute of Unconventional Petroleum Science and Technology, China University of Petroleum (Beijing), Beijing 102249, China
Abstract
Gas flooding and foam flooding are potential technologies for tertiary oil recovery in fractured-vuggy reservoirs. The development and mechanism research of fractured-vuggy reservoirs is difficult due to the complex structures and the strong heterogeneity of fractured-vuggy reservoirs. Visualization simulation is one of the effective methods to study the flow behavior of fluid in fractured-vuggy reservoirs. In this study, an upscaling method of visualization simulation from one dimension (1D) to three dimensions (3D) was established, and the physical models of fractured-vuggy reservoirs were designed and fabricated. Water flooding, gas flooding, and gel foam flooding were carried out in the models. The experimental results showed that gas flooding has a single flow channel and water flooding has multiple flow channels in fractures and vugs. Gel foam with an excellent capability of mobility control and a high microscopic displacement efficiency swept in all directions at a uniform velocity. The EOR mechanisms of gel foam in fractured-vuggy reservoirs were mainly as follows: reducing interfacial tension, increasing mobility ratio, selectively plugging high permeability channels, and discontinuous flow. In the displacement process of fractured-vuggy reservoirs, water should be injected from the well at the bottom of the reservoir, and gas should be injected from the well located in the vug at the high part of the reservoir. Gel foam with strong stability and high viscosity should be selected and injected in most kinds of injection wells in fractured-vuggy reservoirs. This study provides a complete method of visualization simulation for the study of flow behavior in fractured-vuggy reservoirs and provides theoretical support for the application of gas flooding and gel foam flooding in fractured-vuggy reservoirs.
Funder
National Natural Science Foundation of China
Major National Science and Technology Projects of China
Subject
Polymers and Plastics,Organic Chemistry,Biomaterials,Bioengineering
Reference35 articles.
1. Theories and practices of carbonate reservoirs development in China;Li;Pet. Explor. Dev.,2018
2. Distribution features of proved reserves of carbonate oil and gas pools in China;Xie;Mar. Orig. Pet. Geol.,2009
3. Formation, distribution, resource potential, and discovery of Sinian–Cambrian giant gas field, Sichuan Basin, SW China;Zou;Pet. Explor. Dev.,2014
4. Features and classified hierarchical modeling of carbonate fracture-cavity reservoirs;Li;Pet. Explor. Dev.,2016
5. Ordovician carbonate rock matrix fractured-porous reservoirs in Tahe Oilfield, Tarim Basin, NW China;Mao;Pet. Explor. Dev.,2014