论文部分内容阅读
通过分析岩石(铸体)薄片、扫描电镜、X-射线衍射、常规压汞、恒速压汞、测井及生产动态等资料,对歧北斜坡沙河街组二段储层特征、储层低渗成因及优质储层发育机理进行了详细研究。结果表明:储层岩石成分成熟度和结构成熟度较低,孔隙结构及孔渗性能较差;由于储层中塑性岩屑含量较高,抗压实能力弱,在成岩过程中又经历了强烈的压实作用和多期胶结作用,大量孔隙被压实或充填,导致储层物性变差,形成低孔低渗储层。优质储层的发育受多种因素控制,有利沉积微相控制储层的岩石类型和岩石结构,是优质储层形成的物质基础;多期多矿物叠加溶蚀形成大量次生孔隙,是优质储层发育的直接原因;早期油气充注有利于孔隙保存和发育;异常高压是深层孔隙保存的关键。优质储层在整个成岩演化过程中,经历了碱性—酸性—碱性的多重成岩环境;早成岩A期以碱性成岩环境为主,主要发育石英溶蚀型孔隙,早成岩B期—中成岩A1期以酸性环境为主,发育长石、岩屑等溶蚀型孔隙,中成岩A2期,成岩环境重新恢复为碱性,发育第二期石英溶蚀孔隙。储层现今孔隙为多期叠加溶蚀的综合结果。
Based on the analysis of rock (cast) sheet, scanning electron microscope, X-ray diffraction, conventional mercury intrusion, constant pressure mercury injection, logging and production dynamics, the reservoir characteristics, Permeability and high-quality reservoir development mechanism were studied in detail. The results show that the maturity and structural maturity of the rock are low, and the pore structure and porosity and permeability of the rock are poor. Due to the high content of plastic cuttings in the reservoir and the weak ability of compressing and compaction, the rock has undergone intense intense diagenesis Compaction and multi-stage cementation, a large number of pores are compacted or filled, resulting in deterioration of reservoir properties, the formation of low porosity and permeability reservoir. The development of high-quality reservoirs is controlled by many factors. The favorable sedimentary microfacies control the rock type and rock structure of reservoirs, which is the material basis for the formation of high-quality reservoirs. Multi-stage multi-mineral superposition and dissolution form a large number of secondary pores, The direct cause of development; early oil and gas filling is conducive to the preservation and development of pores; abnormal high pressure is the key to deep pore preservation. The high-quality reservoirs experienced alkaline-acidic-alkaline multiple diagenetic environments during the whole diagenetic evolution. The early diagenetic stage A was dominated by alkaline diagenetic environments, mainly consisting of quartz-dissolving pores, pre-diagenesis B-metamorphic rocks Stage A1 was dominated by acidic environment, with feldspar and lithic dissolution pores, diagenetic stage A2, diagenetic environment restored to alkaline, and the second phase of quartz dissolution pores was developed. The porosity of the reservoir nowadays is the result of multi-period overlay erosion.