摘要
寒武系白云岩是塔里木盆地油气勘探的重要接替领域,分析岩心、薄片、扫描电镜、孔渗和地化等资料,研究塔里木盆地寒武系白云岩的储层特征及成岩作用.结果表明:寒武系白云岩储集空间主要由晶间溶孔、溶蚀孔洞和裂缝构成,纯粹由晶间孔组成的储层并不多见;不同类型白云岩的物性差异明显,粉—细晶白云岩储层的物性要好于其他几类白云岩的;研究区建设性成岩作用主要有浅埋藏期白云石化、同生期大气水溶蚀、表生岩溶及热液溶蚀作用,破坏性成岩作用主要包括胶结作用、过度白云石化作用、方解石及自生矿物的充填作用等;特别是受过度白云石化作用的影响,寒武系白云岩中晶间孔发育程度较低,因此后期的岩溶和热液改造是储层形成的关键.
The Cambrian dolomite reservoir is one of the most important potential fields for petroleum exploration in Tarim basin.The main objectives of this paper are to investigate the reservoir features and diagenesis of the Cambrian dolomite in Tarim basin,based on the analysis of the core,thin-section,SEM,C-O-Sr isotope and petrophysical properties.The results show that the porosity types of the Cambrian dolomite reservoir are mainly composed of intercrystalline solution pore,vug and fracture.It is rare for reservoir that only consists of intercrystalline porosity.The petrophysical properties of the reservoirs are associated with the dolomite types,and the reservoir quality of very fine to fine-crystalline dolomite is the best of all dolomites.The main constructive digenesis include shallow burial dolomitization,contemporaneous dissolution,karstification and hydrothermal dissolution;the destructive digenesis contain cementation,over-dolomitization,calcite and other authigenic minerals void-filling.The late diagenetic dissolution including karstification and hydrothermal corrosion plays an important role for the formation of dolomite reservoir,due to the over-dolomitization leading to the decreasing of intercrystalline pores in the Cambrian dolomite reservoirs.
出处
《东北石油大学学报》
CAS
北大核心
2013年第6期63-74,9,共12页
Journal of Northeast Petroleum University
