华庆地区长6 油层组方解石胶结物特征
网络出版日期: 2012-04-20
基金资助
国家科技重大专项“鄂尔多斯中生界延长组储层特征研究”(编号:2008ZX05001-004-003)资助
Characteristics of calcite cements of Chang 6 oil reservoir set in Huaqing area
Online published: 2012-04-20
华庆地区长6 油层组是鄂尔多斯盆地中生界主要的油气储层和产层,方解石胶结物是导致储层致 密的重要因素之一。薄片、扫描电镜、阴极发光、元素组分及碳、氧同位素分析表明,方解石胶结物除常 见的粒状胶结物和嵌晶式胶结物外,还存在较少泥微晶结构方解石。泥微晶结构方解石是同沉积的湖相 内杂基;沉积期后形成的粒状和嵌晶式方解石胶结物具多种成因机制,其中在早成岩阶段A 期沉淀的方 解石胶结物与铝硅酸盐矿物和变质岩、岩浆岩岩屑的水化作用有关;铁方解石胶结物充填于原生孔隙的 同时,还充填于骨架颗粒溶蚀形成的次生孔隙中,其形成与有机酸对长石等铝硅酸盐矿物的溶蚀作用和 黏土矿物的转化作用有关,为早成岩阶段B 期沉淀作用的产物。大多数方解石、铁方解石的胶结作用对 储层物性起负面影响。
久凯 , 丁文龙 , 李春燕 , 曾维特 . 华庆地区长6 油层组方解石胶结物特征[J]. 岩性油气藏, 2012 , 24(2) : 48 -52 . DOI: 10.3969/j.issn.1673-8926.2012.02.010
The Triassic Chang 6 oil reservoir set in Huaqing area is the main hydrocarbon reservoir and producing formation of Mesozoic in Ordao Basin. The cementation of calcite cements is a major factor for the tight reservoir. The analyses on thin section, cathodoluminescence, elemental composition and carbon isotope show that most of the calcites cemented in granular and poecilitic texture, and a fewcemented in micrite texture which are the matrix of syndepositional lake facies. There are several different genetic mechanisms for the granular and poecilitic calcite cements formed during post sedimentary stages, and the calcite cements deposited during the early diagenetic A stage are in connection with the hydration of aluminumsilicateminerals, metamorphic rocks and magmatic rocks. The ferrocalcite cements filled not only in the primary pore, but also in secondary pores. The formation of ferrocalcite cements are closely related to the aluminum silicate minerals and the transformation of clay mineral and occurred during the early diagenetic B stage. Themost cementation of the calcites and ferrocalcite are disadvantageous for the reservoir properties.
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