致密油藏有效储层下限参数评价——以鄂尔多斯盆地中部Z区块长4+5油层组为例  

Evaluation of Effective Reservoir Lower Limit Parameters of Tight Reservoir:A Case Study of Block Chang 4+5 in Z Area of Central Ordos Basin

作　　者：秦子桢 武富礼 袁珍 尹帅 QIN Zi-zhen;WU Fu-li;YUAN Zhen;YIN Shuai(School of Earth Sciences and Engineering, Xi'an Shiyou Universal, Xi'an 710065, China;College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China)

机构地区：[1]西安石油大学地球科学与工程学院,西安710065 [2]山东科技大学地球科学与工程学院,青岛266590

出　　处：《科学技术与工程》2022年第5期1852-1860,共9页Science Technology and Engineering

基　　金：山东省重点研发计划(公益类)(2019 GGX103021)。

摘　　要：鄂尔多斯盆地中部Z区块长4+5发育陆相致密油储层,致密油藏有效储层下限参数评价对甜点预测及油藏注水开发具有重要指导意义。运用该区长4+5大量岩性、物性资料、测井资料、压汞等资料,建立了致密油储层有效孔隙度解释方法,确定了适用于Z区块长4+5油层评价的岩性、物性、电性、含油性下限标准。结果表明,研究区主要发育长石砂岩。其主要孔隙类型包括粒间孔、粒间溶孔、岩屑溶孔及长石溶孔,孔隙度集中分布在8%~14%,而渗透率则集中分布在0.04×10^(-3)~1×10^(-3)μm^(2)。岩心观察、实验分析及测井参数综合解释结果显示,本区致密砂岩储层的岩性下限为细砂岩,对应油迹级含油级别下限;物性及电性参数下限分别为孔隙度9%、渗透率0.2×10^(-3)μm^(2)、含油饱和度40%、电阻率15Ω·m、声波时差226.4μs/m。此外,砂岩厚度与有效厚度呈一定正相关关系,有效厚度与孔隙度也有一定正相关关系,当储层物性较好以及砂层厚度较大,油层厚度较大;反之,当储层物性较差以及砂层厚度较小时,则主要发育差油层。Continental tight oil reservoir is developed in Block 4+5 of Block Z in central Ordos Basin.The evaluation of effective reservoir lower limit parameters of tight reservoir has important guiding significance for dessert prediction and reservoir waterflooding development.The interpretation method of effective porosity of tight oil reservoir was established by using a large number of lithology,physical property data,logging data and mercury injection data of Chang 4+5 in this area.The lower limit standards of lithology,physical property,electrical property and oil-bearing property suitable for the evaluation of Chang 4+5 reservoir in Z block were determined.The results show that the main rock type in the study area is feldspathic sandstone,followed by lithic feldspathic sandstone.The results of thin section identification show that the main pore types include intergranular pores,intergranular solution pores,cuttings solution pores and feldspar solution pores.The porosity of the Chang 4+5 reservoir group is concentrated in 8%~14%,while the permeability is concentrated in the range of 0.04×10^(-3)~1×10^(-3)μm^(2).The results of core observation,experimental analysis and comprehensive interpretation of logging parameters show that the lithologic lower limit of tight sandstone reservoir in this area is fine sandstone,corresponding to the lower limit of oil-bearing grade.The lower limits of physical and electrical parameters are porosity 9%,permeability 0.2×10^(-3)μm^(2),oil saturation 40%,resistivity 15Ω·m,acoustic time difference 226.4μs/m.In addition,there is a certain positive correlation between sandstone thickness and effective thickness,and there is also a certain positive correlation between effective thickness and porosity.When the reservoir physical property is better and the sand layer thickness is larger,the reservoir thickness is larger;on the contrary,when the reservoir physical property is poor and the sand layer thickness is small,poor oil layers are mainly developed.

关 键 词：鄂尔多斯盆地 致密油储层 长4+5油层组 有效储层 物性下限 

分 类 号：TE122[石油与天然气工程—油气勘探]