准西苏13井区石炭系火成岩有效储层物性下限

LOWER LIMITS OF PHYSICAL PROPERTIES OF EFFECTIVE CARBONIFEROUS IGNEOUS RESERVOIR IN SU13 WELL BLOCK OF WEST JUNGGAR BASIN

有效储层物性下限是进行储层有效厚度统计、储层划分和油藏储量估算的重要依据,研究区石炭系火成岩储层岩性较为复杂,岩石种类较多、组分差异性大并且空间分布及内中的多种属性有着极不匀称的变化,当前国内外学者利用物探资料来判断准西石炭系火成岩有效储层物性下限值的相关研究较少。采用分布函数曲线法和物性试油法分别研究并互相验证进而综合判定物性下限值,避免单一方法的随机性。在此基础上,求取研究区不同层段的物性下限值,建立有效储层物性下限值与储层埋藏深度的拟合方程。研究结果表明:研究区储层多为低孔、中低渗储层,中部区域孔渗相对较高,物性较好,向北部和南部物性逐渐变差;研究区石炭系1500~1900 m及1900~2300 m火成岩有效储层孔隙度下限分别为5.09%、4.93%,渗透率下限分别为0.252 mD、0.198 mD;研究区石炭系火成岩有效储层物性下限与储层埋藏深度呈负相关。

The determination of lower limits of effective reservoir physical properties is an important basis for effective thickness statistics, reservoir division and reservoir reserve estimation. The carboniferous igneous rock in the study area is characterized by multi-period diagenesis, multiple rock types and strong heterogeneity, and the lower limits of effective reservoir physical properties lack systematic research. The distribution function curve method and the physical oil test method are used to study physical property lower limits and the results of two methods are mutually compared to avoid the randomness of a single method. On this basis, the lower limit values of physical properties of different strata in the study area are obtained, and the fitting equation of lower limit value and buried depth of reservoir is established. The results show that the reservoirs in the study area are mostly low-porosity and medium-low-permeability reservoirs, with relatively high porosity and permeability in the central area and good physical property, and the physical properties gradually become worse in the north and south. The effective reservoir porosity of the carboniferous system in the study area from 1500 meters to 1900 meters and from 1900 meters to 2300 meters is 5.09% and 4.93%, respectively, and the lower limit of permeability is 0.252 mD and 0.198 mD, respectively. The lower limit of the effective reservoir property of the carboniferous igneous rock in the study area is negatively correlated with the buried depth of the reservoir.