摘要
滩相灰岩储层发育多种类型的孔隙,不同孔隙类型形成了复杂的孔隙组合,探讨孔隙组合对物性的影响对这类储层的开发具有重要意义。利用铸体薄片观察及压汞实验等方法,对A油田滩相灰岩储层的孔隙组合进行划分,并探讨孔隙组合对储层物性的影响。结果表明,研究区主要产油层段Mishrif组Mi4段和Rumaila组Ru1段分别发育藻屑滩和生屑砂屑滩沉积微相,主要岩石类型有绿藻泥粒灰岩、棘皮泥粒灰岩、生屑砂屑灰岩、砂屑生屑灰岩、生屑绿藻泥粒灰岩等,岩性控制物性,不同岩石类型其孔隙类型差异较大,发育粒间孔、铸模孔、生物体腔孔、基质微孔等孔隙,其中铸模孔和粒间溶孔为优势孔隙,总体可划分出三种孔隙组合,以“粒间溶孔+铸模孔+少量其他孔隙”或“铸模孔+生物体腔孔+少量其他孔隙”的高孔中高渗孔隙组合对应的储层物性最好,孔隙度平均值为24.55%,渗透率平均值为27.5×10^(-3)μm^(2),以“粒间溶孔为主,少量铸模孔或非组构性溶孔及其他类型孔隙”形成的中孔中低渗孔隙组合储层物性中等,孔隙度平均值为13.81%,渗透率平均值为7.63×10^(-3)μm^(2),以“孤立铸模孔+其他类型孔隙”形成的低孔低渗组合对应的储层物性最差,孔隙度及渗透率均平均值分别为5.33%、0.644×10^(-3)μm^(2)。研究表明,不同孔隙组合对储层物性会产生显著影响,分析孔隙组合对物性的影响可以为该类储层刻画提供依据。
There are many types of pores in the beach limestone reservoir,and different types of pores form complex pore combinations.It is of great significance to explore the influence of pore combinations on the physical properties of this kind of reservoir.The pore assemblage of the beach limestone reservoir in A oilfield is divided by the method of cast thin section observation and mercury injection experiment,and the influence of pore assemblage on the physical properties of the reservoir is discussed.The results show that the sedimentary microfacies of algal and biogenic sand shoals were developed in Mi4 member of Mishrif Formation and Rumaila Formation,respectively.The main rock types are green algal pelitic limestone,echinodermatan pelitic limestone,clastic sand-pelitic limestone,clastic sand-pelitic limestone and clastic green algal pelitic limestone.Lithology controls physical properties,and pore types vary greatly among different rock types,such as intergranular pores,mold pores,biological cavity pores and matrix micropores,among which mold pores and intergranular dissolved pores are dominant pores.Three kinds of pore combinations can be divided,and the high-porosity pore combination of"intergranular dissolution hole+mold hole+a few other pores"or"mold hole+biological cavity hole+a few other pores"corresponds to the best reservoir physical properties,with an average porosity of 24.55%and an average permeability of 27.5×10^(-3)μm^(2).The medium porosity and low permeability porosity combination formed by"intergranular dissolved pores mainly,a small number of cast holes or non-fabric dissolved pores and other types of pores"has medium physical properties,with an average porosity of 13.81%and an average permeability of 7.63×10^(-3)μm^(2).The combination of low porosity and low permeability formed by"isolated mold holes+other types of pores"corresponds to the worst reservoir physical properties,and the mean values of porosity and permeability are 5.33%and 0.644×10^(-3)μm^(2),respectively.The study shows that d
作者
张茜然
段广慧
许家铖
伏美燕
ZHANG Xiran;DUAN Guanghui;XU Jiacheng;FU Meiyan(College of Energy,Chengdu University of Technology,Chengdu 610059;Research Institute of Petroleum Exploration and Development,Petrochina,Beijing 100083)
出处
《四川地质学报》
2024年第3期400-407,共8页
Acta Geologica Sichuan
关键词
伊拉克地区
白垩系
滩相灰岩
孔隙组合
Iraq region
Cretaceous system
beach facies limestone
pore combination
