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四川盆地高石梯东部地区上震旦统灯影组微生物碳酸盐岩是重要的天然气产层。结合区域地质研究,通过岩心观察、镜下鉴定,对研究区微生物碳酸盐岩岩石学、成岩作用类型及序列展开系统研究,明确了储集空间特征,探讨了储层发育主控因素。上震旦统灯影组微生物碳酸盐岩以白云岩为主,岩石类型主要包括叠层石、球粒岩、凝块石和泡沫绵层白云岩。微生物白云岩储层主要发育于灯四上段、灯四下段和灯二段,储集空间类型以发育窗格孔、空腔溶洞、粒间溶孔、晶间溶孔和铸模孔为特征,优质储层段孔隙度一般在1%~6%之间,渗透率一般小于1×10-3μm2。微生物白云岩储层发育的控制因素主要包括原始岩石类型和成岩作用。原始沉积岩石中的微生物结构决定了储层的储集空间类型和孔隙结构特征;成岩作用是储层是否发育的关键因素,建设性成岩作用包括早期微生物白云石化作用、埋藏溶蚀作用与岩溶作用;破坏性成岩作用主要包括过度白云石化作用和硅化作用。
The upper Sinian Dengying Formation in the eastern part of the Gaoshiti area, Sichuan Basin, is an important natural gas production layer. In combination with regional geology research, through core observation and microscopic identification, systematic study on microbial carbonate rock petrology and diagenesis types and sequences in the study area was carried out. The reservoir space characteristics were clarified and the main controlling factors of reservoir development were discussed. The Upper Sinian Dengying Formation microbial carbonate rocks are dominated by dolomite. The major types of rocks include stratiform, pelitic, clinker and foam foam dolomite. Microbial dolomite reservoirs are mainly developed in the upper part of lamp 4, the lower part of lamp 4 and the lamp 2, and the types of storage space are characterized by the development of panes, cavities, intergranular dissolution pores, intercrystalline dissolution pores and mold holes, The porosity of the reservoir section is generally between 1% and 6%, and the permeability is generally less than 1 × 10-3μm2. The controlling factors of microbial dolomite reservoir development mainly include the original rock type and diagenesis. The microbial structure in the original sedimentary rocks determines the type of reservoir space and pore structure; diagenesis is the key factor for the development of the reservoir; the constructive diagenesis includes the early microbial dolomitization, burial dissolution and karstification; Destructive diagenesis mainly includes over-dolomitization and silicification.