| 摘要: |
| 塔里木盆地西北地区苏盖特布拉克组发育一套潮坪相沉积，是该层系油气勘探的主要目标。基于什艾日克剖面、奇格布拉克剖面、肖尔布拉克剖面的地质测量，采用薄片鉴定、阴极发光、扫描电镜、流体包裹体测温及黏土矿物X衍射等分析手段开展海相碎屑岩成岩作用和成岩演化研究，为塔里木盆地苏盖特布拉克组进一步开展油气勘探部署和甜点储层预测提供地质依据。结果表明：（1）研究区苏盖特布拉克组发育潮坪沉积环境的砂体，砂岩类型以岩屑石英砂岩、岩屑砂岩为主，偶见长石岩屑砂岩，成分成熟度和结构成熟度中等；（2）苏盖特布拉克组砂岩经历了压实（溶）作用、胶结作用、溶蚀作用及交代作用等成岩作用，压实作用是造成储层致密的直接原因，钙质胶结和硅质胶结是储层致密化的根本因素；（3）苏盖特布拉克组砂岩的成岩演化阶段已达到中成岩B期，成岩演化序列为：压实作用/自生黏土矿物（绿泥石）环边—第一期长石、岩屑溶蚀作用—第一期硅质胶结—第一期泥微晶方解石胶结/压溶作用/黏土矿物的伊利化—第二次硅质胶结/第二期铁方解石胶结—钙质胶结物溶蚀。据此建立的成岩演化模式为塔里木盆地超深层致密砂岩中甜点储层预测提供可靠的地质依据。 |
| 关键词: 成岩作用 成岩模式 潮坪相碎屑岩 苏盖特布拉克组 塔西北地区 |
| DOI：10.19826/j.cnki.1009-3850.2022.04017 |
| 附件 |
| 投稿时间：2021-10-11修订日期：2022-04-27 |
| 基金项目:中国石油化工股份有限公司科技开发项目（P17046-4） |
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| Diagenesis and diagenetic evolution of tidal flat facies clastic rocks of Sinian Sugetbrak Formation in Northwest Tarim Basin |
| ZHENG Xiaoyu, ZHANG Xiang, LI Jian, TIAN Jingchun, PENG Minghong, ZHANG Qiyuan, ZHANG Yue |
(1. Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China;
2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology), Chengdu 610059, China;
3. College of Earth Science, Chengdu University of Technology, Chengdu 610059, China) |
| Abstract: |
| A set of tidal flat facies deposits are developed in the Sugetbrak Formation in the northwest of the Tarim Basin, which is the main target of oil and gas exploration in this formation. Based on the geological survey of Shiairike, Qigebrak and Qiaoenbrak sections, the diagenesis and diagenetic evolution of marine clastic rocks are studied by means of thin section identification, cathodoluminescence, scanning electron microscope, fluid inclusion temperature measurement and clay mineral X-diffraction, so as to provide a geological basis for further oil and gas exploration deployment and reservoir prediction of the Sugetbrak Formation in the Tarim Basin. The results show that: (1) Sand bodies in tidal flat sedimentary environment are developed in the Sugetbrak Formation in the study area, the sandstones are mainly lithic quartz sandstone and lithic sandstone, and feldspathic lithic sandstone is occasionally seen, with medium compositional maturity and structural maturity; (2) The sandstone of the Sugetbrak Formation has experienced diagenesis such as compaction, cementation, dissolution and replacement. Compaction is the direct cause of reservoir densification, and calcareous and siliceous cementation are the fundamental factors of reservoir densification; (3) The diagenetic evolution stage of Sugetbrak sandstones has reached the middle diagenetic stage B. the diagenetic evolution sequence is: compaction / autogenous clay mineral (chlorite) rim - the first stage feldspar and rock debris dissolution - the first stage silica cementation - the first stage mud microcrystalline calcite cementation / pressure dissolution / illitization of clay minerals - the second stage silica cementation / the second stage iron calcite cementation - calcium cement dissolution. The diagenetic evolution model provides a reliable geological basis for the prediction of ultra-deep tight sandstone reservoirs in the Tarim Basin. |
| Key words: diagenesis diagenetic stage tidal flat clastic rock Sugetbrak Formation northwest Tarim Basin |
