摘要
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。
Based on regional geology, core description and thin section observation, the petrology and reser- voir properties of the microbial carbonates of Upper Sinian Dengying Formation （Z2dn） in eastern Gaoshiti area in the Sichuan Basin are investigated in detail.The origin of the microbial dolostone is analyzed briefly. Dolostones dominate in microbial carbonate rocks of Dengying Formation and the lithology include stromatolite, spherulite, thrombolite and spongy layered dolomite.Microbial dolostone reservoirs are mainly devel- oped in both the upper ＆ lower parts of Zzdnl ,and in Z2dn2.The reservoir space is composed of fenestral pores, skeleton cavities, inter-particle dissolution pores, inter-crystal dissolution pores and moldic pores.The good reservoirs mostly have a porosity range of 1% to 6% and permeability of less than 1×10^-3μm^2.The formation and distribution of the microbial dolomite reservoirs are jointly controlled by the original rock type and digenesis. Different microbial textures in the originally deposited rocks determined the types of reservoir space and pore structure. Diagenesis is a key factor for development of microbial reservoirs. The constructive diagenesis for forming good reservoirs are early microbial dolomitization,karst,and burial dissolution;while the destructive diagenesis are over-dolomitization and intense silicification.
作者
翟秀芬
汪泽成
罗平
王铜山
石书缘
张洪
Zhai Xiu -fen Wang Ze-cheng Luo Ping Wang Tong-shan Shi Shu-yuan Zhang Hong(Research Institute of Petroleum Exploration ＆ Development ,PetroChina ,Beijing 100083 ,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第8期1199-1210,共12页
Natural Gas Geoscience
基金
国家科技重大专项(编号2016ZX05004)
中国石油股份公司科技重大专项(编号:2014E-32-01)联合资助
