摘要
川东北地区飞仙关组储集岩主要是白云岩。白云石化成因类型对勘探有利区块和勘探目标的选择都具有重要的意义。研究认为,区内飞仙关组岩石中的白云石主要有三种类型:第一种为半自形—他形细—中晶白云石;第二种为泥晶白云石;第三种为自形中晶-粗晶白云石。它们在有序度,C、O同位素,微量元素,包裹体,阴极发光等方面具有不同的地球化学特征。通过研究认为,这三种类型的白云石成因分别为混合水白云石化、渗透回流白云石化和埋藏白云石化。其中混合水白云石化是该区优质鲕滩储层得以发育的主要成岩因素之一,有利的混合水白云石化带主要发生在台地边缘鲕坝(滩)中,这也是鲕滩储层发育的最有利地区,渗透回流白云石化主要发生在台地边缘鲕粒坝(滩)后方的局限海环境中,其分布范围大致与石膏分布范围一致,储集物性略差。
The Feixianguan Formation reservoir rocks in Northeast Sichuan are mainly composed of dolostones. Through investigation it was considered that the dolomites in Feixianguan Formation may be divided into three types: the first is the hypautomorphic-xenomorphic finemedium crystalline grain dolomite; the second is the dolomicrite and the third is the automorphic medium-coarse crystalline grain dolomite. They have different geochemical characteristics in the degree of order, the carbon and oxygen isotopes, the microelement, the inclusion, the cathodoluminescence, and so on. The geneses of these three types of dolomites are mixed water dolomitization, seepage reflux dolomitization and burial dolomitization respectively, in which the mixed water dolomitization. was one of principal diagenetic factors causing the excellent oolitic beach reservoir being well developed in the region. The beneficial mixed water dolomitization zones mainly occurred in the oolitic bar (beach) along platform edge, of which the distribulation area is roughly identical with that of gypsum, its petrophysical property being slightly poor.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2005年第4期40-41,共2页
Natural Gas Industry
基金
国家"十五"科技攻关项目(编号:2001BA605A-04-03)的部分研究成果
