鄂尔多斯盆地南部长7致密油储层评价及分类

发布时间：2018-05-01 19:42

  本文选题：鄂尔多斯盆地南部 + 长7　； 参考：《西北大学》2017年硕士论文

【摘要】：随着全球油气消耗量的不断增长,常规油气资源开发力度的不断加大,常规油气储量大幅较小,作为常规油气资源的接替区,非常规油气资源逐渐引起了人们的广泛关注。鄂尔多斯盆地致密油资源丰富,储集层规模大、石油充注程度高,但其储层为致密储层、储层孔隙结构复杂、非均质性强、油水渗流关系复杂、资源动用程度低,严重制约着盆地内致密油资源的高效开发。因此,此次研究以鄂尔多斯盆地南部长7致密油储层为对象,结合岩心、钻测井、铸体薄片、显微成像及实验测试资料,对长7致密油储层基础地质特征、砂体结构特征、孔隙结构特征、渗流特征及岩石力学特征进行研究,优选、拟合最能表征储层各特征的参数,建立可用于研究区致密油开发过程中有利储层选择的致密油储层分类评价标准,并对研究区储层进行分类。结合研究区长7致密油储层特征,经过综合考虑,确定从储层砂体结构、孔隙结构、渗流特征及岩石力学特征方面入手对研究区储层进行评价,在评价过程中优选出两项定性评价参数(砂体结构、水驱油驱替类型),六项定量评价参数(流动带指标FZI、最大喉道半径、可动流体有效孔隙度、油水两相共渗区范围、启动压力梯度、储层岩石矿物脆性指数)用以建立储层分类评价标准。研究区储层箱型砂所对应的孔隙度、渗透率指最大,钟型其次,漏斗型及指型所对应孔隙度、渗透率值最小,储层砂体物性最差;流动带指标数值越大,表明储层孔隙、喉道匹配性越好；岩心最大喉道半径是致密储层渗透率的主控因素；可动流体有效孔隙度能反映出储层物性的好坏及孔喉配置结构的优劣;水驱油驱替方式可以定性表征储层渗流能力;储层岩心油水两相共渗范围越大,储层渗流能力越好;启动压力梯度与岩心气测渗透率呈现出很好的负相关性,启动压力梯度越大,储层渗流能力越差;矿物脆性指数及力学脆性指数对储层的岩石力学特征进行评价,研究发现储层矿物脆性指数及力学脆性指数大小变化较为一致,与矿物脆性指数相比,力学脆性指数由于受储层内裂缝影响整体偏小,因此优选矿物脆性指数用以评价储层岩石力学特征。在所选八项评价参数的的基础上,选择六元分类系数法,将六项定量评价参数进行拟合,得到定量综合评价指标Feci,结合八项单因素参数,建立研究区致密油储层分类评价标准,将研究区致密油储层分为Ⅰ～Ⅳ类。
[Abstract]:With the increasing of global oil and gas consumption and the increasing development of conventional oil and gas resources, the conventional oil and gas reserves are much smaller. As a replacement area of conventional oil and gas resources, unconventional oil and gas resources have been paid more and more attention. The Ordos Basin is rich in dense oil resources, large reservoir size and high degree of oil filling, but its reservoir is compact reservoir, with complex pore structure, strong heterogeneity, complex oil-water percolation relationship and low resource utilization. The efficient exploitation of dense oil resources in the basin is seriously restricted. Therefore, taking the South 7 tight oil reservoir in Ordos Basin as the object, combining the core, drilling logging, casting thin slice, microscopic imaging and experimental test data, the basic geological characteristics and sand body structure characteristics of the Chang 7 tight oil reservoir are analyzed. The pore structure, percolation and rock mechanics characteristics are studied, selected optimally, the parameters which can best represent the reservoir characteristics are fitted, and the classification and evaluation standard of dense oil reservoir is established, which can be used to select favorable reservoir in the development process of dense oil in the study area. The reservoir in the study area is classified. Combined with the characteristics of Chang 7 tight oil reservoir in the study area, through comprehensive consideration, the reservoir is evaluated from the aspects of reservoir sand body structure, pore structure, percolation characteristics and rock mechanics characteristics. In the process of evaluation, two qualitative evaluation parameters (sand body structure, water drive oil displacement type), six quantitative evaluation parameters (flow zone index FZI, maximum throat radius, effective porosity of movable fluid, range of oil-water two phase common permeability zone) are selected. Starting pressure gradient and reservoir rock mineral brittleness index) are used to establish reservoir classification and evaluation criteria. The porosity corresponding to reservoir box sand in the study area is the largest permeability index, followed by bell type, funnel type and finger type, the minimum permeability value and the worst physical property of reservoir sand body, the larger the flow zone index value, the more the reservoir porosity. The better the matching of throat is, the more the maximum throat radius of core is the main controlling factor of tight reservoir permeability, the effective porosity of movable fluid can reflect the physical property of reservoir and the advantage and disadvantage of pore throat configuration structure. The reservoir percolation ability can be qualitatively characterized by water drive oil displacement mode; the larger the reservoir core oil-water two phase common permeability range is, the better the reservoir percolation ability is, and the starting pressure gradient has a good negative correlation with the gas permeability measurement in the rock core. The larger the starting pressure gradient is, the worse the percolation capacity of reservoir is, and the mineral brittleness index and mechanical brittleness index are used to evaluate the rock mechanics characteristics of reservoir, and it is found that the change of mineral brittleness index and mechanical brittleness index is consistent. Compared with the mineral brittleness index, the mechanical brittleness index is less affected by the fractures in the reservoir, so the mineral brittleness index can be used to evaluate the mechanical characteristics of the reservoir rock. On the basis of the eight evaluation parameters selected, the six-element classification coefficient method is selected to fit the six quantitative evaluation parameters, and the quantitative comprehensive evaluation index Fecie is obtained. Combining with eight single factor parameters, the classification and evaluation criteria for dense oil reservoirs in the study area are established. The dense oil reservoirs in the study area are divided into 鈪，

本文编号：1830791