鄂尔多斯盆地华池-合水地区长3_1储层孔喉结构特征  

Pore throat structure characteristics of Chang 3_1 reservoir in Huachi-Heshui area,Ordos Basin

作　　者：廖明光[1,2] 郭芸菲 姚泾利[3] 廖纪佳[1,2] 南郡祥[3] LIAO Mingguang;GUO Yunfei;YAO Jingli;LIAO Jijia;NAN Junxiang(Sichuan Provincial Key Laboratory of Natural Gas Geology, Southwest Petroleum University, Chengdu 610500, China;School of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, China;Research Institute of Exploration ＆ Development, PetroChina Changqing Oilfield Company, Xi＇an 710018, China)

机构地区：[1]四川省天然气地质重点实验室.西南石油大学,成都610500 [2]西南石油大学地球科学与技术学院,成都610500 [3]中国石油长庆油田分公司勘探开发研究院,西安710018

出　　处：《岩性油气藏》2018年第3期17-26,共10页Lithologic Reservoirs

基　　金：国家自然科学基金项目"泥质岩层对低渗透砂岩储层油气成藏的控制机理研究"(编号:41502146);国家重点基础研究发展(973计划)项目"中国陆相致密油(页岩油)形成机理与富集规律基础研究"(编号:2014CB239005)联合资助

摘　　要：鄂尔多斯盆地华池—合水地区长31低渗透砂岩储层物性差、孔喉结构复杂,存在注水开发效率低的问题,基于高压压汞、恒速压汞技术对孔喉特征进行研究,并结合镜下薄片鉴定及扫描电镜分析,探讨了微观孔喉结构的成因。结果表明:依据高压压汞实验结果可将储层孔喉发育程度分为较好、适中及较差等3类,依据恒速压汞实验结果可将储层分为Ⅰ类大孔中细喉型、Ⅱ类大孔细喉型和Ⅲ类大孔微细喉型等3类;不同孔喉结构储层孔隙特征相似,喉道特征差异明显,储层物性受单位体积有效孔隙体积与喉道参数影响,其中孔隙度主要受单位体积有效孔隙体积、单位体积有效喉道体积和单位体积有效喉道数量影响,渗透率主要受单位体积有效孔隙体积和喉道半径影响;Ⅰ类、Ⅱ类、Ⅲ类储层孔喉比依次增大,孔喉配置关系依次变差,孔喉比与渗透率负相关性好;微观孔喉结构受胶结作用、溶蚀作用控制,胶结作用越弱,溶蚀作用越强,孔喉结构越好。The Chang 31 low permeability sandstone reservoir in Huachi-Heshui area of Ordos Basin suffers low efficiency in water injection development, which results from the poor formation physical properties and complex pore throat structure. In order to formulate a reasonable development scheme, the pore throat characteristics were investigated by high pressure mercury injection and rate-controlled mercury injection technique. Microscopic identification and scanning electron microscope analysis were also conducted to discuss the genesis of microscopic pore throat structure. The results of high pressure mercury injection experiment show that reservoir porosity de- velopment could be classified into three types, including superior one, moderate one and poor one. According to the constant-rate mercury injection experiment, the reservoirs could be classified into type Ⅰ large pore and mid- fine throat, type Ⅱ large pore and fine throat, and type Ⅲ large pore and tiny throat. Regarding the formations with different pore-throats structures, the pore characteristics are similar but the throat characteristics are evidently different. The reservoir physical properties are influenced by effective pore volume per unit volume and throat pa- rameters. Porosity is mainly influenced by effective pore volume per unit volume, effective throat volume per unit volume and number of effective throats per unit volume. Permeability is mainly influenced by effective pore volume per unit volume and the radius of the throat. The pore throat ratio of type Ⅰ , type Ⅱ and type Ⅲ reservoirs increase successively and the pore throat configuration relationship deteriorates successively. The pore throat ra- tio is negatively correlated with the permeability. The micropore throat structure is controlled by cementation and dissolution. The weaker cementation resulted in stronger dissolution and better microDore throats structure.

关 键 词：低渗透储层 高压压汞 恒速压汞 孔喉结构 长31储层 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]