【作者】 许海龙；

【导师】 贾承造； 魏国齐；

【作者基本信息】 中国地质大学(北京) ， 矿产普查与勘探， 2012， 博士

【摘要】 乐山—龙女寺古隆起是发育在四川盆地中西部、潜伏于二叠系之下的巨型不规则鼻状构造，面积约占四川盆地的三分之一，是四川盆地天然气勘探的重要领域。论文在前人工作的基础上，采用最新高精度地震勘探资料和钻测井数据进行精确构造解释，精细刻画出乐山—龙女寺古隆起结构与形态。系统研究古隆起不整合特征、建立构造层序、恢复其构造演化过程。全面分析古隆起构造演化对震旦系天然气成藏的影响，指出有利勘探区域。论文研究取得了以下成果和认识：（1）论文采用最新地震勘探资料和钻测井数据进行精确构造解释，精细刻画出古隆起9个主要层系构造特征。（2）论文首次明确提出乐山—龙女寺古隆起平面具有分区特征。川西小区构造圈闭规模较小，褶皱和断裂作用相对较强烈。威远小区以威远穹窿背斜为主，其北侧分布资阳鼻状小褶曲群。川中小区总体构造变形较弱，构造圈闭从北向南可再划分为三排。（3）论文系统分析古隆起主要不整合面构造特征。首次提出并采用空间趋势外推法恢复桐湾期、加里东期和印支期不整合剥蚀量。依据不整合发育特征，将区内地层划分为6个一级构造层序，13个二级构造层序。（4）论文依据不整合特征和构造层序，重新将古隆起构造演过程划分为雏形阶段、发育阶段、稳定埋藏阶段和调整定型阶段。首次指出古隆起显著构造变形发生于奥陶纪末加里东运动塔科尼幕，志留纪至二叠纪仅发生整体升降运动。（5）论文研究表明不同时期的古隆起构造格局决定了烃源岩、储层、构造圈闭在时空上的匹配关系，建立了乐山—龙女寺古隆起震旦系天然气成藏模式。（6）论文从古隆起构造演化的角度指出，高石梯—磨溪潜伏构造带震旦纪以来长期处于构造高部位，构造圈闭完整、气源充足，是最具勘探前景的有利区块。更多还原

【Abstract】 Leshan-Longnvsi paleo-uplift is a giant irregular structural nose developed underPermian in the central and western of the Sichuan Basin, covering an area aboutone-third of the basin, which is an important area of gas exploration. On the basis ofprevious work, the paper using the latest high-precision seismic data, logging data anddrilling data to interpret the paleo-uplift’s structure and describe its morphology. Itsystematically discussed the features of unconformities, established the tectonicsequences and restored paleo-uplift’s tectonic evolution and deeply analyzed theeffects of the evolution on Sinian gas accumulation, pointed out the favorableexploration area. The research achieved the following results and understanding:(1) Using the latest seismic data and drilling and logging data to interpretstructure accurately and describe structural features of 9 strata meticulously.(2) The paper pointed out that the paleo-uplift has horizontal partitioncharacteristics clearly first time. Structures in western Sichuan area are smaller thanother area and the folding and faulting is relatively strong. The Weiyuan fornixanticline is the main structure of the Weiyuan area, and the Ziyang small nosing foldgroup locates on the north side of it. The overall tectonic deformation of central areais weak and the structures from north to south can be further divided into three rows.(3) The paper systematically analyzed the major unconformities’structuralfeaturesof the paleo-uplift, proposed and used the method of‘spatial trendextrapolation’to restored the eroded amount of Tongwanian, Caledonian andIndosinian unconformities. According to the featuresof unconformities of thepaleo-uplift, the region strata were divided into which has six level-1 and 13 level-2tectonic sequences.(4) Based on the features of unconformities and of the tectonic sequences, theevolution of the paleo-uplift was divided into four stages: the embryonic stage, thedevelopmental stage, the stable burial stage and the adjust-shaping stage. Thesignificant tectonic deformation of Leshan-Longnvsi paleo-uplift occurred duringCaledonian movement Taconian episode. During the Silurian Period to the Permian,the paleo-uplift occurs only lifting movement as a whole, there is no obvious structural deformation.（5）Studies have shown that the paleo-uplift’s tectonic framework of thedifferent periods restrained the the matching of source rocks, reservoir and traps intime and space, establish the gas accumulation model of Sinian(6) Gaoshiti area is long-term structural high since Sinian. It has entire structuraltrap and sufficient gas source, is the most favorable area.更多还原