A static resistance model and the discontinuous pattern of hydrocarbon accumulation in tight oil reservoirs  

作　　者：Sun Liang Zou Caineng Liu Xiaoli Zhu Rukai Wang Xiaoqi 

机构地区：[1]Research Institute of Petroleum Exploration and Development,PetroChina [2]Department of Hydraulic Engineering, Tsinghua University

出　　处：《Petroleum Science》2014年第4期469-480,共12页石油科学（英文版）

基　　金：supported by the Chinese Major National Scientific and Technological Program (2011ZX05001);Chinese Postdoctoral Fund (2013M540114)

摘　　要：In exploration for tight oil, the content and saturation of hydrocarbon in the tight reservoir is a key factor for evaluating the reserve. Therefore, it is necessary to study the geological history of hydrocarbon accumulation and the tight oil charging process. However, kinetic models used for petroleum development are not applicable for petroleum exploration. In this study, a static resistance model[ is proposed after analyzing resistances in ultra-slow flow in porous media. Using this model, the disco^atinuous pattern of oil charging is reproduced through incompressible Navier-Stokes equations, the phase field method and the finite element method. This study also explains macroscopic percolation behavior with microscopic flow mechanisms and discusses some issues in ultra-slow flow in a micro/nano pore-throat network. The resistance analysis reveals that capillary resistance and dissipation resistance are dominant factors in the mechanism of oil accumulation in tight reservoirs. Numerical simulations show that pressure thresholds exist and result in discontinuous oil charging. Generally, it is proven that the static model is more applicable than kinetic models in describing oil accumulation in tight reservoirs.In exploration for tight oil, the content and saturation of hydrocarbon in the tight reservoir is a key factor for evaluating the reserve. Therefore, it is necessary to study the geological history of hydrocarbon accumulation and the tight oil charging process. However, kinetic models used for petroleum development are not applicable for petroleum exploration. In this study, a static resistance model[ is proposed after analyzing resistances in ultra-slow flow in porous media. Using this model, the disco^atinuous pattern of oil charging is reproduced through incompressible Navier-Stokes equations, the phase field method and the finite element method. This study also explains macroscopic percolation behavior with microscopic flow mechanisms and discusses some issues in ultra-slow flow in a micro/nano pore-throat network. The resistance analysis reveals that capillary resistance and dissipation resistance are dominant factors in the mechanism of oil accumulation in tight reservoirs. Numerical simulations show that pressure thresholds exist and result in discontinuous oil charging. Generally, it is proven that the static model is more applicable than kinetic models in describing oil accumulation in tight reservoirs.

关 键 词：Tight oil oil charging WETTABILITY capillary pressure static resistance pressure threshold 

分 类 号：P618.13[天文地球—矿床学]