致密岩心启动压力梯度实验研究  

Study on Experiment of Threshold Pressure Gradient for Tight Sandstone

作　　者：朱维耀[1] 田巍[1] 朱华银[2] 张雪龄[1] 和雅琴 李勇[3] 王瑞明[3] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]中国石油勘探开发研究院廊坊分院,廊坊065007 [3]华北油田勘探开发研究院,任丘062552

出　　处：《科学技术与工程》2015年第3期79-83,共5页Science Technology and Engineering

基　　金：国家重点基础研究发展计划(973计划)(2013CB228002)资助

摘　　要：为了研究致密岩心的启动压力梯度,对室内渗流实验设备进行优化改进,并借鉴现有测试方法,设计出了"非稳态驱替-瞬间动用法",并针对吐哈油田岩心开展了室内研究,研究表明:所选取岩心的最小启动压力梯度、拟启动压力梯度和两相启动压力梯度数值较大,平均值分别0.476 3 MPa/m、1.298 2 MPa/m和2.299 5 MPa/m,且随着渗透率的降低而呈现幂函数级增加,随着渗透率倒数的增加而线性增加;两相启动压力梯度高于单相,最小启动压力梯度和两相启动压力梯度分别反映了单相和两相流体动用所需的真实驱动压力梯度,因此后者可以作为油田开发设计的重要参数;拟启动压力梯度对现场参考意义不大;分析可知,致密储层开发开采难度较大。In order to study threshold pressure gradient for tight sandstone and carrying out a research into the core of Tuha oil field,based on the existing experimental equipment and the method to test,designed the method of transient displacement-instant threshold,and carried on the related research.Research shows that minimum threshold pressure gradient,pseudo threshold pressure gradient and two phase threshold pressure gradient of these cores selected are all larger,The average value is respectively 0.476 3 MPa / m,1.298 2 MPa / m and 2.299 5 MPa / m,and firstly reduced sharply,then reduced at lower speed along with increase of permeability,as increasing along with the reciprocal permeability increases.Moreover,two phase threshold pressure gradient is higher than that of single phase.Minimum threshold pressure gradient and two phase threshold pressure gradient respectively represent the real driving pressure gradient of single-phase and two-phase fluid starting,so the latter can be regarded as an important parameters in the process of oil field development and design.Pseudo threshold pressure gradient is represent the fluid driving pressure of the average throat radius.However,because test procedures and data processing is more complicated,and more factors influenced,the test results is not much meaning.Based on the above analysis,the method designed is more feasible,which can be widely applied to test real threshold pressure gradient in the lab.The research of this paper shows that it is more difficult to develop tight sandstone reservoir.

关 键 词：致密岩心 最小启动压力 改进 压差流量法 两相启动压力 非稳态驱替-瞬间动用法 

分 类 号：TE348[石油与天然气工程—油气田开发工程]