基于自吸实验的页岩有效渗透率确定方法

Determination Method of Effective Permeability Based on Imbibition for Shale Reservoir

曾凡辉 蒋静 马健 郭建春 穆轲帆

ZENGFanhui JIANGJing MAJian GUOJianchun MUKefan

油气藏地质及开发工程全国重点实验室·西南石油大学, 四川 成都 610500 中国石化西南油气分公司工程技术研究院, 四川 德阳 610105

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China Engineering Research Institute, Southwest Petroleum Branch, SINOPEC, Deyang, Sichuan 610105, China

有效渗透率是表征页岩储层特征的关键参数之一。针对致密页岩储层通过常规流动实验获取有效渗透率受到极大限制这一难题，开展了基于自吸实验预测岩石有效渗透率方法的研究。研究中首先通过开展页岩自吸实验获取自吸能力系数，综合考虑页岩渗透压、迂曲度、动态毛管力等因素，建立基于自吸能力系数的储层有效渗透率预测方法。结果表明，建立的有效渗透率预测方法考虑因素全面、需要参数较少、计算过程清晰，更符合地层真实情况；渗透压、迂曲度对有效渗透率有明显影响，忽略渗透压将导致有效渗透率结果偏大，不考虑迂曲度导致有效渗透率预测结果偏小，为有效、快速评价页岩储层有效渗透率提供一种新途径。

Effective permeability is one of the key parameters to characterize shale reservoirs. Due to the density of shale reservoir, it is of great difficulty to obtain the effective permeability through by core flow experiment. In order to solve the problem, a method to predict the effective permeability of rock based on imbibition experiment is established in this paper. Firstly, the spontaneous imbibition coefficient is obtained through shale spontaneous imbibition experiment, and the effective permeability prediction method based on the spontaneous imbibition coefficient is established by comprehensively considering the permeability pressure, tortuosity and dynamic capillary force of shale. The results show that the effective permeability prediction method established in this paper takes into account all factors, requires fewer parameters, and has a clear calculation process, which is more in line with the real formation situation. Osmotic pressure and tortuosity have obvious influence on effective permeability. Ignoring osmotic pressure will lead to a higher prediction of effective permeability, and ignoring tortuosity will lead to a lower prediction of effective permeability. This paper provides a new way to evaluate effective permeability of shale reservoir effectively and quickly.

10.11885/j.issn.1674 5086.2024.11.12.03