摘要
鄂尔多斯盆地姬塬油田长6储层压实作用和成岩作用强烈,储层的强非均质性制约了油气勘探效益的提高。通过开展常规物性、图像粒度、铸体薄片、X衍射、扫描电镜、高压压汞和恒速压汞等实验研究储层的微观特征,以时间为主轴,综合沉积环境、埋藏深度、古地温、构造等因素,采用"成岩演化特征"和"地质综合效应"相结合的方法建立了姬塬油田长6致密砂岩储层的孔隙度演化模拟方程,分析了致密砂岩储层成岩作用、孔隙演化等的成因机理。孔隙度演化计算结果表明姬塬油田长6段致密砂岩储层初始孔隙度为37.33%,压实作用损失的孔隙度为22.47%,早期胶结-交代损失的孔隙度为3.69%,产生的次生孔隙度为6.53%,中晚期胶结-交代过程孔隙度损失平均值为6.97%,计算孔隙度平均值为10.06%。致密砂岩储层的差异性成岩演化过程是导致储层物性和微观孔隙结构差异的根本原因。
In the Ordos Basin,the effects of compaction and diagenesis are strong in the Chang 6 reservoir of the Jiyuan Oilfield,and the great heterogeneity has limited the oil and gas development. This paper first studied the microscopic characteristics of the reservoir via microcosmic experiments including conventional physical properties,image granularity,casting lamella,X-ray diffraction,high-pressure mercury injection,constant speed mercury injection and SEM. Taking time as the main factor and integrating with the depositional environment,burial depth,paleotemperature,tectonism and other minor factors,we established the porosity evolution simulation equations of tight sandstone reservoir at Chang 6 by using the diagenetic evolution characteristics and geological comprehensive effects. We analyzed the formation mechanism of the diagenesis effect and porosityevolution in tight sandstone reservoirs. Computing results of porosity evolution show that the initial porosity of the Chang 6 reservoir was 37. 33%,the porosity loss by compaction effect was 22. 47%,porosity loss by early phase cement-metasomatism was 3. 69%,secondary porosity was 6. 53%,the porosity loss by middle and late phase cement-metasomatism was 6. 97%,and the porosity was 10. 06% on average. We suggest that the differential diagenetic evolution process of tight sandstone reservoir is the fundamental cause of the physical property differences and micro-pore structures.
作者
黎盼
孙卫
杜堃
黄何鑫
白云云
LI Pan;SUN Wei;DU Kun;HUANG Hexin;BAI Yunyun(State Key Laboratory for Continental Dynamics,Department of Geology,Northwest University,Xian,Shaanxi710069,China)
出处
《现代地质》
CAS
CSCD
北大核心
2018年第3期527-536,共10页
Geoscience
基金
国家科技重大专项"大型油气田及煤层气开发"(2011ZX05044)
陕西省科技统筹创新工程项目(2015KTCL01-09)
陕西省教育厅专项科研计划项目(15JK1063)
关键词
姬塬油田
长6储层
致密砂岩
差异性成岩
孔隙度演化
Jiyuan Oilfield；Chang 6 reservoir；tight sandstone；differential diagenesis；porosity evolution
