Title: CO2 miscible flooding influence degree analysis of reservoir heterogeneity in low permeability reservoir

Authors: Jinkai Wang; Jun Xie; Hao Lu

Addresses: College of Geoscience and Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China ' College of Geoscience and Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China ' College of Geoscience and Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China

Abstract: In this paper, a later period of water flood reservoir is taken for example to simulate the reservoir heterogeneity influence degree on CO2 flooding. The research was started from studying the heterogeneity influence mechanism, then the two-dimensional plane model, two-dimensional profile model, three-dimensional model have been built to evaluate the CO2 flooding efficiency influence degree of the plane and vertical and interlayer heterogeneity. The results show that the serious reservoir heterogeneity can lead to inject gas breakthrough in one direction or one layer which can reduce the recovery percent. The high vertical in-layer heterogeneity can cause large number of enrichment of remaining oil at the bottom of layer. Relatively, thin effective sand bodies and water alternate gas (WAG) injection type can effectively reduce the influence degree of vertical heterogeneity, which can significantly improve oil recovery percent. [Received: July 28, 2015; Accepted: January 14, 2016]

Keywords: CO2 flooding; reservoir heterogeneity; water alternate gas; WAG; oil displacement effect; Gaoyou sag; carbon dioxide; low permeability reservoirs; simulation; modelling; China; maturing oilfields; oil reservoirs.

DOI: 10.1504/IJOGCT.2016.078783

International Journal of Oil, Gas and Coal Technology, 2016 Vol.13 No.2, pp.142 - 158

Received: 22 Aug 2015
Accepted: 14 Jan 2016

Published online: 02 Sep 2016 *

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