低渗透储层多参数渗透率测井评价新方法

A new multi parameter permeability evaluation method for low permeability reservoirs

本研究区位于鄂尔多斯盆地西南部。目的层C81储层主要以岩屑长石砂岩和长石砂岩为主,少量长石岩屑砂岩、岩屑砂岩,C8_(1)储层整体孔隙度在8%~20%之间,平均值为15.51%,渗透率在0.1~10mD之间,平均值为5.07mD,属于超低渗透储层。其中C8_(1)^(2)孔隙度在12%~22%,平均16.21%,渗透率在0.1~20mD,平均6.34mD,并且孔隙度与渗透率相关性较差,相关系数仅为0.42,但局部发育高孔、高渗段,渗透率非均质性严重,导致渗透率模型建立困难。本文针对研究区储层特点,以测井信息和岩石物理实验为基础,以储层连通性分析为桥梁,建立基于岩性和孔隙结构的多参数渗透率计算新模型,有效解决了一个孔隙度对应多个渗透率问题,提高了测井解释评价精度,为油藏高效开发提供测井技术支撑。

The study area is located in the southwest of Ordos Basin.The C81 reservoir is mainly composed of lithic arkose and arkose,with a small amount of lithic arkose and lithic sandstone.The overall porosity of C81 reservoir is between 8%~20%,with an average value of 15.51%,and the permeability is between 0.1~10mD,with an average value of 5.07mD,which belongs to ultra-low permeability reservoir.The porosity of C812is 12%~22%,with an average of 16.21%,and the permeability is 0.1~20mD,with an average of 6.34mD.The correlation coefficient between porosity and permeability is only 0.419,but the high porosity and high permeability section are developed locally,and the permeability heterogeneity is serious,which makes it difficult to establish the permeability model.According to the reservoir characteristics of the study area,based on logging information and petrophysical experiments,taking reservoir connectivity analysis as a bridge,a new multi parameter permeability calculation model based on lithology and porestructure is established,which effectively solves the problem of one porosity corresponding to multiple permeabilities,improves the accuracy of logging interpretation and evaluation,and provides logging technical support for efficient reservoir development.