饶阳凹陷沙河街组碎屑岩储层碳酸盐胶结物形成机制及其对储层质量的影响

发布时间：2018-01-09 14:01

  本文关键词：饶阳凹陷沙河街组碎屑岩储层碳酸盐胶结物形成机制及其对储层质量的影响　出处：《矿物岩石》2017年02期 　论文类型：期刊论文

  更多相关文章： 碳酸盐胶结物 碳氧同位素 储层质量 形成机制 沙河街组 饶阳凹陷

【摘要】：通过薄片鉴定、扫描电镜和阴极发光观察对饶阳凹陷沙河街组碎屑岩储层的22口探井864个薄片样品的碳酸盐胶结物进行期次划分,再据各期胶结物的共生矿物研究、碳氧同位素分析、流体包裹体测温等对其形成机制进行研究。研究结果表明研究区共发育3期碳酸盐胶结物:第一期以粒状方解石为主,其形成于岩石充分压实之前的早成岩阶段,伴生少量的黄铁矿胶结;第二期以粒状细晶级为主,多发育方解石、白云石,以斑块状以及嵌晶式连生方式赋存,与前期的胶结物之间常形成一层黏土薄膜;第三期以柱状或粒状细晶级形式存在,以方解石、白云石、铁方解石以及铁白云石成分为主,充填长石等易溶性颗粒溶孔及交代早期碳酸盐胶结物。据胶结物碳氧同位素分析恢复古盐度Z值及测算古地温判断早期胶结物来源于古盐度较高的淡水成因流体;再根据胶结物流体包裹体均一温度判断方解石胶结物形成于中成岩A期,为有机酸脱羧基生成大量CO_2,使化学平衡向着生成碳酸盐的方向移动,表示其"碳"来源为有机碳。对储层质量影响方面,早期碳酸盐胶结物增加了砂体的抗压实能力,对研究区储层质量的影响是正面的,而中后期碳酸盐胶结物充填长石及岩屑溶蚀作用形成的孔隙,对储层质量的影响是负面的。
[Abstract]:The carbonate cementation of 864 thin slice samples in 22 exploration wells of Shahejie formation in Raoyang sag was divided by scanning electron microscope and cathodoluminescence observation. Based on the study of symbiotic minerals in each period, carbon and oxygen isotopes were analyzed. The formation mechanism of fluid inclusions was studied by temperature measurement. The results show that the carbonate cementation in the study area is of three stages: the first stage is mainly granular calcite. It was formed in the early diagenetic stage before the rock was fully compacted, accompanied by a small amount of pyrite cementation. The second stage is mainly granular fine grained with calcite and dolomite occurring in the form of plaques and embedded crystals. A layer of clay film is often formed between the grained fine grained grains and the early cemented materials. The third stage exists in the form of columnar or granular fine grained, mainly composed of calcite, dolomite, iron calcite and iron dolomite. Filling feldspar and other easily soluble granular dissolved pores and carbonate cement in early metasomatism. Recovery of paleosalinity Z value by carbon and oxygen isotopic analysis of cementation and estimation of paleo-geothermal temperature to judge that the early cementation originated from freshwater fluids with high paleosalinity. ; According to the homogenization temperature of cemented material inclusions, calcite cementation was formed in the middle diagenetic A stage, and a large amount of CO2 was formed from organic acid decarboxyl group, which made the chemical balance move towards the direction of carbonate formation. It is indicated that the source of "carbon" is organic carbon. In terms of the effect on reservoir quality, the early carbonate cement increases the compaction resistance of sand body, and the effect on reservoir quality in the study area is positive. The effect of carbonate cementation on reservoir quality is negative due to the formation of pores formed by feldspar and lithic dissolution.
【作者单位】： 油气藏地质及开发工程国家重点实验室(成都理工大学);中国石油天然气股份有限公司华北油田分公司;中国石油西南油气田公司川中油气矿;四川师范大学地理与资源科学学院;
【基金】：国家自然科学基金项目(41372141) “十三五”国家重大专项(2016ZX05024002-007)
【分类号】：P618.13
【正文快照】： 1.油气藏地质及开发工程国家重点实验室(成都理工大学),四川成都610059;2.中国石油天然气股份有限公司华北油田分公司,河北任丘062552;3.中国石油西南油气田公司川中油气矿,四川遂宁629001;4.四川师范大学地理与资源科学学院,四川成都p膒苝蘰，

本文编号：1401647