靖边潜台西北侧马五段碳酸盐岩古岩溶储层的形成与天然气成藏规律

发布时间：2018-01-11 07:25

  本文关键词：靖边潜台西北侧马五段碳酸盐岩古岩溶储层的形成与天然气成藏规律　出处：《西北大学》2016年博士论文　论文类型：学位论文

  更多相关文章： 靖边气田 沉积相 古地貌 碳酸盐岩储层 气水分布 天然气成藏

【摘要】：鄂尔多斯盆地下古生界奥陶系马五段主要以碳酸盐岩为主,以1989年在陕参1井马五段获得高产气流为标志,现已发现靖边大型气田。马五段碳酸盐岩储层形成时代老,经历了多期复杂的成岩演化,储层非均质强,气、水分布规律复杂,成藏过程研究有待深化。已发现的靖边气田主要位于岩溶潜台,其西北侧是目前增储上产的重点地区。因此开展该地区沉积相、古地貌古岩溶特征、储层特征,结合气、水分布规律及包裹体流体示踪研究探讨下古生界天然气成藏过程,对马五段碳酸盐岩勘探、开发具有重要的理论意义和应用价值。利用测井、录井、岩心观察等基础资料,结合铸体薄片、扫描电镜、阴极发光等分析手段,对研究区沉积相、古地貌和古岩溶特征进行了研究;根据压汞、气水相渗、核磁共振、主微量元素、稀土元素、Sr和C/O同位素等实验数据综合研究了储层的特征,并对储层进行了综合评价；基于试气数据和地层水分析数据,总结了气、水分布的控制因素,以流体包裹体分析为基础,结合天然气成藏条件分析,探讨天然气成藏规律。研究认为,马五段沉积环境为潮上带-潮问带沉积,发育5种沉积微相,水体主要从北东东、南西及南东方向侵入。西北部为岩溶高地,局部发育残丘及洼地,中东部为岩溶斜坡,发育缓丘、浅洼和近东西向展布的5条古沟槽。储层经历了同生期岩溶、表生期岩溶和埋藏期岩溶,岩溶高地上的残丘、岩溶斜坡中的缓丘及沟槽两侧部位为有利岩溶储层发育地区。储层岩石类型以白云岩为主,含裂缝、孔洞的物性比基质物性好,胶结充填作用,溶蚀作用对储层物性改造较大。马五1亚段中白云石+石英+高岭石胶结-溶孔相、马五2亚段中白云石+石英+方解石胶结-溶孔相以及马五4’亚段中白云石+石英+高岭石胶结-溶孔相的物性最好。发育溶孔-晶间(溶)孔复合型(Ⅰ类)、晶间(溶)孔-裂缝型(Ⅱ类)、裂缝-微孔隙型(Ⅲ类)和微孔隙型(Ⅳ类)等四类孔隙结构。白云石化作用主要发生在油气生成前的浅-中等埋藏期,其次为发生在准同生期和生物化学生气阶段,脉体状方解石主要形成于烃源岩排烃之后的中-深埋藏阶段。气、水分布宏观受控于古岩溶地貌与成岩作用背景,微观上受控于储层的物性、孔隙连通性。晚侏罗世早期,发生第1期油气充注,形成小范围气藏；早白垩世晚期发生第1Ⅱ期油气运移和成藏,此后气藏经调整后在残丘、缓丘及沟槽两侧高部位聚集,形成了现今的气藏形态。
[Abstract]:The lower Paleozoic Ordovician Ma-Wu formation in Ordos Basin is dominated by carbonate rocks, marked by the high gas flow obtained in Shaanshen No. 1 formation in 1989. It has been found that the carbonate rock reservoir of the fifth member of the formation age of Jingbian gas field, experienced multiple periods of complex diagenetic evolution, the reservoir heterogeneity, gas and water distribution is complex. The discovered Jingbian gas field is mainly located in the karst submersible platform, and the northwest side of the gas field is the key area where the reservoir is increased. Therefore, the sedimentary facies, paleogeomorphology and palaeokarst characteristics and reservoir characteristics are developed in this area. The study of gas and water distribution law and fluid tracer of inclusions is of great theoretical significance and application value for exploration and development of carbonate rocks in the Lower Paleozoic. The characteristics of sedimentary facies, paleogeomorphology and paleokarst in the study area were studied by means of core observation and other basic data, combined with casting thin slice, scanning electron microscope and cathodoluminescence. According to the experimental data of mercury injection, gas-water permeation, nuclear magnetic resonance, main trace elements, rare earth elements such as Sr and C / O isotopes, the reservoir characteristics are comprehensively studied, and the reservoir is evaluated synthetically. Based on gas test data and formation water analysis data, the controlling factors of gas and water distribution are summarized. Based on fluid inclusion analysis and natural gas accumulation condition analysis, the law of natural gas accumulation is discussed. There are five sedimentary microfacies developed in the sedimentary environment of the fifth member, namely, the upper tidal belt and the tidal zone. The water body mainly invades from the north, west, south and east. The northwest is the karst highland, and the residual hills and depressions are locally developed. The middle and eastern part is a karst slope, with a gentle hill, shallow depression and 5 paleo-trenches distributed near east-west. The reservoir experienced syngenic karst, supergene karst and burial karst, and the residual hills in karst highlands. The areas on both sides of the gentle hills and grooves in karst slopes are favorable for the development of karst reservoirs. The main rock types of the reservoirs are dolomite, the physical properties of fractures and cavities are better than those of matrix, and the cementation filling process. Dissolution has great influence on the reservoir physical properties. The dolomite quartz kaolinite cementation and dissolved pore facies in the Ma 51 submember. The physical properties of dolomite quartz calcite cementation phase and dolomite quartz kaolinite kaolinite cementation phase are the best in the Ma Wu 2 submember. Class 鈪，

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