鄂尔多斯盆地华庆地区三叠系长9成岩作用及孔隙演化研究  

Research on diagenesis and pore evolution of Triassic Chang9 reservoir in Hua-Qing area, Ordos Basin

作　　者：叶博[1,2] 牛小兵[1,2] 梁晓伟[1,2] 李卫成[1,2] 郝炳英[1,2] 宋娟[1,2] 

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,710018 [2]低渗透油气田勘探开发国家工程实验室

出　　处：《低渗透油气田》2016年第2期34-40,共7页

摘　　要：通过大量砂岩样品铸体薄片、扫描电镜及阴极发光等资料分析，华庆地区长9储层砂岩主要成岩作用有压实压溶作用、胶结作用及溶蚀作用等。其中压实压溶作用、绿泥石膜、浊沸石、硅质等胶结作用使该区长9砂岩物性变差，而溶蚀作用，尤其是长石和浊沸石的溶蚀使致密储层的储渗性能得到改善，局部形成相对高孔、高渗储层。华庆地区长9砂岩中存在浊沸石胶结物，而延长组长9以上层位没有浊沸石胶结物，研究认为与该区长9储层砂岩长石碎屑含量高、水下分流河道砂体沉积厚度大、埋藏较深有关。长9砂岩孔隙类型以粒间孔为主，长石溶孔、浊沸石溶孔次之。经过估算，华庆地区长9储层砂岩原始孔隙度约为34．6％～34．3％。压实和胶结作用损失的孔隙度为25．5％-27．5％，后期溶蚀作用增加的孔隙度为2．4％～2．5％。因此，次生孔隙发育形成的相对高孔、高渗储层是长9储层下步勘探的重要目标区。The main diagenesis of the Chang9 reservoirs sandstone in Hua （chi） -Qing （cheng） area is compaction and pressolution, cementation, and dissolution, etc., based on the data analysis of casting lamella, scanning electron microscope, and cathodoluminescence of a large number of sandstone samples. The compaction and pressolution, chlorite film, laumontite/lomontite, siliceous cementation etc. make the physical properties of the Chang9 sandstone in this area worse ; while the dissolution, especially the dissolution of feldspar and laumontite, makes the tight reservoirs＇ properties （esp. the permeability） improved, locally forming relatively high porosity and permeability reservoirs. The Chang9 sandstone in the Hua-Qing area has laumontite/lomontite cement, while there is no lomontite cement in the horizons above the Yanchang Formation. The research shows that these are related to the high content of feldspathic detritus in the sandstone, large sedimentary thickness and deep burial depth of the underwater distributary channel sand bodies in the Chang9 reservoirs of the area. The pore types of the Chang9 sandstone is dominated by intergranular pores, followed by feldspar dissolution and lomontite dissolution pores. The original porosity of the Chang9 reservoir sandstone in the Hua- Qing area is estimated to be 34. 6% - 34. 3% ; the porosity lost by compaction and cementation is 25.5% -27.5% ; the porosity increased by late dissolution is 2. 4%- 2.5%. Therefore, the relatively high porosity and permeability reservoirs formed by secondary pores development are important target areas for the next step exploration of the Chang9 reservoirs.

关 键 词：成岩作用 孔隙演化 浊沸石 华庆地区 鄂尔多斯盆地 

分 类 号：TE21[石油与天然气工程—油气井工程]