川东南赤水地区构造特征及其对成藏控制作用研究

发布时间：2018-06-12 07:01

本文选题：赤水地区 + 断层相关褶皱　；参考：《成都理工大学》2017年硕士论文

【摘要】：在前人研究基础上,利用地震剖面结合钻井资料以及平衡剖面方法定性定量分析川东南赤水地区构造及演化特征,同时采用构造砂箱模拟手段对研究区滑脱层形成上下两套不匹配构造变形的控制因素及变形过程进行实验研究,对比分析构造对下伏深层-超深层油气藏的保存作用,从而为川东南地区深层油气成藏研究提供理论依据。研究区整体构造呈现由盆外到盆内变形强度逐渐减弱的趋势,受SE-NW和SW-NE两个方向应力场同时叠加作用,造成了现今两组构造形迹的分布,其构造变形及演化主要受中上寒武统膏盐岩滑脱层控制,形成滑脱层上、下不同的构造变形样式:滑脱层之上构造变形晚且变形强,背、向斜连续相间分布,褶皱几何形态受控于核部或两翼发育的大型逆断层,滑脱层于背斜核部加厚并向两翼逐渐减薄,断层向下终止于滑脱层内;滑脱层之下地层构造稳定,变形强度较弱,仅局部有小的隆起。滑脱层之上地层位移缩短量是滑脱层之下的6.4-10倍,形成断滑与断展的复合构造,其变形程度和变形特征不仅受滑脱层控制还与变形快慢有关。以川东南地层条件为约束所进行的砂箱模拟实验验证了上述结论。因此,研究区中上寒武统滑脱层作为时代最老、厚度最大的一套滑脱层直接影响了川东南赤水地区多条断层的形成演化、褶皱形态的变化和西门构造区双层构造样式的形成。在此研究基础上根据区域挤压的强弱程度和滑脱层的分布,可以将川东南地区构造对油气保存条件的差异划分为三个带:(1)造山带-盆地边缘强变形带;(2)盆地边缘-川东南北东部中强变形带;(3)盆地边缘-盆内赤水地区弱变形带。川东南地区早期构造保存条件较好,推测其油气成藏经历了以下几个阶段:二叠纪-三叠纪形成灯影组古油藏→三叠纪-侏罗纪油裂解形成古气藏→晚白垩世古气藏调整和破坏阶段。在强至中强变形带保存条件变差,油气直接通过断层或侧向运移逸散。但盆地内弱变形带,滑脱层之下圈闭条件持续存在,侧向及垂向保藏条件均比其余地区好,具有良好的勘探前景。
[Abstract]:On the basis of previous studies, the structural and evolutionary characteristics of Chishui area in southeastern Sichuan are analyzed qualitatively and quantitatively by seismic profile combined with drilling data and balanced profile method. At the same time, by means of structural sand box simulation, the controlling factors and deformation process of the upper and lower sets of unmatched structural deformation of the slip layer in the study area are studied experimentally, and the effects of the structure on the preservation of the down-deep and ultra-deep reservoirs are compared and analyzed. It provides theoretical basis for the study of deep oil and gas accumulation in southeast Sichuan. The whole structure of the study area shows the tendency of weakening the deformation intensity from the outside basin to the inside basin, and the stress field of SE-NW and SW-NE superposes at the same time, which results in the distribution of the two groups of tectonic patterns. The tectonic deformation and evolution are mainly controlled by the middle and upper Cambrian gypsum rock detachment, forming different structural deformation patterns above and below the slippage layer: late and strong tectonic deformation above the slippage layer, the back and syncline continuous phase distribution, the tectonic deformation and evolution are mainly controlled by the middle and upper Cambrian gypsum rock slippage layer. The geometry of the fold is controlled by the large thrust fault developed in the nucleus or wings, the slip layer is thickened in the nucleus of the anticline and gradually thinned down to the two wings, and the fault terminates in the delamination layer, the strata beneath the slip layer are stable in structure and the deformation intensity is relatively weak. There are only small bulges. The displacement shortening of the stratum above the slip layer is 6.4-10 times of that under the slip layer, which forms a composite structure of fault-slip and fault-spreading. Its deformation degree and deformation characteristics are not only controlled by the slip layer, but also related to the deformation speed and speed. The above conclusions are verified by sand box simulation experiments with the formation conditions in southeast Sichuan. Therefore, the Middle and Upper Cambrian detachment is the oldest and thickest set of slip beds in the study area, which directly affects the formation and evolution of many faults, the changes of fold morphology and the formation of double-layer structural style in Ximen tectonic area. On the basis of this study, according to the degree of regional compression and the distribution of slip layer, The difference of oil and gas preservation conditions in southeast Sichuan can be divided into three zones: 1) orogenic belt-strong deformed zone of basin margin) basin margin-middle and strong deformation zone of east and south of Sichuan province-3) margin of basin and weak deformation zone of Chishui area in basin. The early tectonic preservation conditions in southeastern Sichuan are good. It is inferred that the formation of oil and gas reservoirs has gone through the following stages: the period of Permian-Triassic formation of Dengying formation and the stage of adjustment and destruction of Paleocene gas reservoirs during the late Cretaceous of Paleo-gas reservoir formed by oil cracking of Triassic to Jurassic. In the strong to moderate deformation zones, the preservation conditions become poor, and the oil and gas migrate and dissipate directly through faults or sideways. However, the weak deformation zone in the basin, the trap conditions under the slip layer are persistent, the lateral and vertical preservation conditions are better than those in the other areas, and the exploration prospect is good.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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