鄂尔多斯盆地中西部长9储层差异化成岩与烃类充注过程研究

发布时间：2018-05-29 00:22

本文选题：差异化成岩作用 + 烃类充注　；参考：《地质学报》2017年05期

【摘要】：储层非均质性极大地影响储层内流体的流动和分布,在油气运移成藏和提高采收率研究中广受关注。储层内发生的差异化成岩作用是层内非均质性的重要成因,与烃类充注事件的相互关系也是致密砂岩油气成藏机理研究的核心内容。本文以鄂尔多斯盆地中西部上三叠统延长组长9储层为例,研究储层内砂岩所表现出的差异化成岩作用及其影响下的流体活动过程。系统的显微观察发现,长9储层主要由机械压实致密型砂岩、钙质胶结致密型砂岩、含水砂岩和含油砂岩等四类岩石组成。利用显微岩相学、紫外荧光光谱、包裹体均一温度测试、盆地模拟等技术综合分析表明,机械压实致密型砂岩在早成岩期即在压实作用影响下强烈塑性变形致密化;钙质胶结致密型砂岩在早成岩期就发生强烈的碳酸盐胶结作用而致密化。这两类砂岩在成岩中后期基本不能为流体活动提供孔隙空间。含水砂岩和含油砂岩均经历了复杂的差异化成岩过程,含油砂岩内可以辨识出至少三期沥青,含水砂岩则未见沥青残留。以含油砂岩中沥青质所对应的烃类充注为标志,重建了长9储层的成岩序列,划分出三期流体流动过程,烃类充注与成岩作用交替进行。含水砂岩大致可划分出相似的成岩过程,但未发生烃类充注。
[Abstract]:Reservoir heterogeneity greatly affects the flow and distribution of fluid in the reservoir. The differential diagenesis occurring in the reservoir is an important cause of the heterogeneity in the reservoir, and the relationship with hydrocarbon filling and injection events is also the core of the study on the hydrocarbon accumulation mechanism of tight sandstone. Taking Yanchang 9 reservoir of Upper Triassic in the central and western part of Ordos Basin as an example, the differential diagenesis of sandstone in the reservoir and the process of fluid activity under its influence are studied in this paper. The systematic microscopic observation shows that Chang 9 reservoir is mainly composed of four types of rocks: mechanically compacted tight sandstone, calcareous cemented tight sandstone, water-bearing sandstone and oil-bearing sandstone. The comprehensive analysis of microlithology, ultraviolet fluorescence spectrum, homogenization temperature test of inclusions and basin simulation shows that the mechanical compacted tight sandstone is strongly densified by plastic deformation during early diagenesis, i.e. under the influence of compaction. Calcareous cemented dense sandstone is densified by strong carbonate cementation during early diagenesis. These two types of sandstone can not provide pore space for fluid activity in the middle and late diagenetic stage. Both water-bearing sandstone and oil-bearing sandstone have undergone complex differential diagenetic processes. At least three stages of bitumen can be identified in oil-bearing sandstone, but no bitumen residue is found in water-bearing sandstone. Based on hydrocarbon filling corresponding to asphaltene in oil-bearing sandstone, the diagenetic sequence of Chang 9 reservoir is reconstructed, and three stages of fluid flow process are divided. Hydrocarbon filling and diagenesis are alternately carried out. The water-bearing sandstone can be divided into similar diagenetic processes, but no hydrocarbon filling occurs.
【作者单位】：中国石油化工股份有限公司石油勘探开发研究院;中国科学院地质与地球物理研究所;
【基金】：国家科技重大专项(编号2011ZX08005-004,2016ZX05002-006) 国家自然科学基金项目(编号41372151)联合资助成果
【分类号】：P618.13

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