摘要
页岩储层中存在纳米孔隙、微米孔隙、微裂隙和裂缝等多尺度孔隙结构。为了认识页岩储层的多尺度渗流规律,采集涪陵龙马溪组页岩岩样,利用改进的实验装置,开展了吸附/解吸、应力敏感和扩散等实验。实验结果表明:吸附/解吸基本符合兰格缪尔方程;渗透率与有效应力符合指数函数关系;扩散系数随温度的升高而增大,符合Fick扩散定律。基于渗流力学理论分析了页岩储层的多尺度渗流机理,认为页岩气在基质中的流动包括由压力差所引起的渗流、浓度差引起的扩散以及由于压力降低而引起的页岩气解吸,裂缝中的流动为压力差引起的渗流。基于实验及理论分析,建立了页岩储层多尺度综合渗流数学模型,为页岩气井渗流规律研究、产能评价及生产动态分析奠定基础。
There are multi-scale pore structures in shale reservoirs,such as nano pores,micron pores,microfractures and fractures. In order to understand the seepage law of shale gas in the shale reservoir with multiscale pore structure,the adsorption/desorption,stress sensitivity and diffusion experiments of the shale samples collected from Fuling Longmaxi formation were carried out by using the improved experimental equipment. The experimental results show that,the adsorption/desorption accords with Langmuir equation; the relationship between reservoir permeability and effective stress is in accordance with exponential function; the diffusion coefficient increases with the increase of temperature,which is in accordance with Fick＇s diffusion law. Based on the theory of seepage mechanics,the seepage mechanism of shale gas in multi-scale shale reservoir is analyzed,and it is held that the flow of shale gas in the shale matrix includes the seepage caused by pressure difference,the diffusion caused by concentration difference and the desorption of shale gas caused by the decrease of pressure,and the flow in the crack is caused by pressure difference. Based on the experimental results and theoretical analysis,a comprehensive seepage mathematical model of multi-scale shale reservoir was established,which lays the foundation for the study of the seepage law of shale gas wells,the evaluation of productivity and the dynamic analysis of production.
作者
刘华
王卫红
陈明君
刘启国
胡小虎
LIU Hua;WANG Weihong;CHEN Mingjun;LIU Qiguo;HU Xiaohu(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 100083,China;Research Institute of Petroleum Exploration and Development,SINOPEC,Beijing 100083,China;Southwest Petroleum University,Chengdu 610500,Sichuan,China)
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2018年第4期66-71,共6页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家科技重大专项"涪陵页岩气开发示范工程"(2016ZX05060-002)
中国石化科技部项目"川东南深层页岩气产能评价及有效开发技术政策研究"(P16063)
关键词
页岩储层
渗流规律
多尺度孔隙结构
岩页气渗流数学模型
解吸
扩散
shale reservoir
seepage law
multi-scale pore structure
mathematical model for shale gas seepage
desorption
diffusion
