基于毛管束模型的启动压力梯度分析与计算  

Analysis and Calculation of Threshold Pressure Gradient Based on Capillary Bundle Model

作　　者：邱志鹏[1] 杨胜来[1] 任双双 刘京 陈仁保 徐斌[1] 李滢[1] 马铨峥[1] 韩伟[1] 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249 [2]冀东钻采工艺研究院,北京100000

出　　处：《科学技术与工程》2016年第17期127-132,共6页Science Technology and Engineering

基　　金：中国石油股份公司"十二五"重大科技专项基金(11.2011E-2500.X.01)资助

摘　　要：针对低渗岩心渗流规律研究和室内实验测定中准确计算启动压力梯度的方法,提出启动渗透率的概念,认识到启动压力梯度和启动渗透率在渗流过程中是变化的,对冀东油田低渗透岩心通过稳态"流量-压差"法进行驱替实验,建立了用于分析启动压力梯度变化规律的毛细管束模型。对实验结果处理和分析,研究结果表明启动压力梯度和启动渗透率随流量的增加而增加;并且增加的幅度逐渐减小。由启动压力梯度和流量的关系计算出了不同实验岩心的最小启动压力梯度、拟启动压力梯度及对应的启动渗透率,得到启动压力梯度与岩心渗透率呈幂函数关系的经验公式;并将一维实验结果应用于平面径向流中,指出启动压力梯度随距离增加而减小,并得到启动压力占总驱替压差的比例。In order to study the flow in low permeability porous media and exactly calculate threshold pressure gradient in laboratory experiment,a new conception of active permeability are put forward. It is believed that threshold pressure gradient and active permeability are changing in the flow process. The steady ＂flow rate-pressure difference＂flooding experiment is conducted using natural cores in a low permeability reservoir,a capillary bundle model is set up to analyze and calculate threshold pressure gradient. Results show that threshold pressure gradient and active permeability are increased when flow rate increased,and the rate of increasing gradually reduced. The minimum threshold pressure gradient,pseudo threshold pressure gradient and corresponding active permeability of different cores are calculated according to the relationship between threshold pressure gradient and flow rate. And a power function formula of threshold pressure gradient and core permeability is established. The lab result is applied into radius flow,and indicate that the threshold pressure gradient decreases with the distance increases.

关 键 词：低渗透 启动压力梯度 启动渗透率 毛管束模型 

分 类 号：TE311.11[石油与天然气工程—油气田开发工程]