致密砂岩储层应力敏感性实验研究  

Experiment of the stress sensitivity of tight sandstone reservoirs

作　　者：钟高润[1] 张小莉[1] 杜江民[1,2] 陈兴官[3] 徐立明 牟宣 

机构地区：[1]西北大学大陆动力学实验室/西北大学地质学系,西安710069 [2]石家庄经济学院资源学院,石家庄050031 [3]中国石油长庆油田分公司第一采气厂,靖边718500 [4]中石油煤层气有限责任公司,北京100028

出　　处：《地球物理学进展》2016年第3期1300-1306,共7页Progress in Geophysics

基　　金：中国石油天然气股份有限公司重大科技专项“鄂尔多斯盆地致密油勘探开发关键技术研究”(2011E-2602);陕西省重点学科“地质资源与地质工程”和河北省教育厅资助科研项目(QN2015255)联合资助

摘　　要：研究的背景：在油田开采过程中,随着地层压力的下降,作用在岩石颗粒上有效应力的增加,均会使岩石颗粒发生变形,产生应力敏感,降低储层的孔隙度和渗透率,影响流体在多孔介质中的渗流特征,给油田的合理开发带来诸多困难.研究方法及目的：利用美国Core Laboratory公司的仪器进行孔隙度、渗透率的测定,结合扫描电镜、铸体薄片以及核磁共振技术分析鄂尔多斯盆地延长组长7段低孔、低渗储层的应力敏感性.研究结果：（1）在定覆压变孔压和定孔压变覆压条件下,孔隙度、渗透率均随着孔隙压力的减小、上覆压力的增大而减小,属于＂先快后慢＂型的应力敏感性损害模式.孔隙度相对损失率1.21%-3.28%,渗透率相对损失率44%-70%,渗透率应力敏感性较强.（2）在有效应力压差相同情况下,渗透率相对损失率小于40%时,定孔压变覆压引起的渗透率损失率较大;渗透率相对损失率大于40%时,定覆压变孔压引起的渗透率损失率较大.（3）孔隙度应力敏感性与岩石的微观孔隙结构、孔隙大小及岩石颗粒的抗压能力有关,而渗透率主要与岩石的孔喉、孔隙尺寸分布有关.研究意义：为致密油勘探开发中保持合理的生产压差,减轻储层应力敏感性损害,为提高油井产能和采收率提供一定的实验依据.Research background： In the process of oil field exploitation,the reservoir pressure declining and the effective stress in rock particles increasing will deform the rock particles,stress sensitivity,reduce the porosity and permeability and influence reservoir fluid in the porous media seepage characteristics. So it will bring many difficulties for oil field development. Research methods and purposes： Using the Core Laboratory ＇s instrument determine the porosity and permeability,combined with the scanning electron microscopy（ SEM）,the casting thin sections and the analysis of the nuclear magnetic resonance（ NMR） technology,We analyze the low porosity and low permeability reservoir stress sensitivity in Chang 7 member Yanchang Formation in Ordos Basin. The results show： first,when the overburden pressure and porosity pressure are constant values,porosity and permeability are decreased with the decrease of pore pressure and the increase of overlying pressure,the damage mode of porosity and the permeability can be described as＂Falling quickly then falling slowly ＂. The relative loss rate of porosity is from 1. 21% to 3. 28%, the relative loss rate of permeability is from 44% to 70%. Permeability has stronger stress sensitivity. Second,in the case of differential pressure is the same,when the relative loss rate of permeability is less than 40%,the permeability loss mainly caused by the increase of overlying pressure; when the relative loss rate of permeability is more than40%,the permeability loss mainly caused by the decrease of pore pressure. Third,the porosity stress sensitivity is connected with the microscopic pore structure of the rock porosity,pore size and rock particles compressive capacity,and permeability is mainly affected by the pore distribution and pore size distribution. Implications for research： they can provide certain experiment basis for maintaining reasonable production pressure,reducing the stress sensitivity of reservoir damage and improving well productivity and recovery

关 键 词：储层损害 应力敏感性 孔隙结构 损害模式 

分 类 号：P631[天文地球—地质矿产勘探]