【作者】 陈桂菊；

【导师】 姜在兴；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2007， 博士

【摘要】 川西前陆盆地上三叠统须家河组碎屑岩储层是川西前陆盆地重要的勘探领域和层系之一,由于川西前陆盆地产层埋深较深,成岩作用程度较强,受长期挤压作用影响,故其储层多为低孔低渗的致密储层,非均质性强,物性差,勘探难度很大,因此深入研究其储层特征具有重要意义。本文运用油气沉积学、储层地质学、矿物岩石学、地球化学以及储层评价等理论和方法技术,对川西前陆盆地上三叠统须家河组碎屑岩储层的岩石学特征、砂体成因类型及分布、成岩作用类型、孔隙类型及演化、物性特征及其影响因素等进行了深入的研究,取得了以下主要成果:1.在川西前陆盆地中通过岩石薄片观察、扫描电镜以及电子探针分析,在须二段发现石英溶蚀现象,首次在研究区论证了石英溶蚀现象存在的合理性,指出了石英直接溶蚀发生的地区位置,分析了导致石英溶蚀发生的碱性流体的来源以及酸、碱溶蚀现象发生的顺序,量化了碱性溶蚀对储层物性的影响特征。2.提出了一套有效的储层成岩相研究方法,即将成岩相研究与区域构造运动、沉积环境、盆地流体性质以及物源特征相结合,分析研究区主要单因素成岩相,再将各单因素成岩相进行有机叠加即可划分储层综合成岩相,建立成岩相与储层物性之间的因果关系。本次研究将川西前陆盆地须家河组储层划分为6种单因素成岩相和11种综合成岩相类型,提出影响须家河组储层的成岩相主要是绿泥石衬边、溶蚀和破裂成岩相、压实压溶、硅质胶结和碳酸盐胶结成岩相。3.构造、沉积-层序和成岩作用综合控制了研究区优质储层的发育,在不同构造单元储层主控因素又有所差别:冲断带储层主要受构造裂缝控制;前渊坳陷带储层受裂缝和成岩作用控制;前缘斜坡带储层为沉积-层序及成岩作用控制;前陆隆起带受沉积-层序因素控制;优质储层主要发育于斜坡带和隆起带。4.结合川西前陆盆地储层特征以及生产实际,制定储层评价与分类标准,对川西前陆盆地上三叠统碎屑岩储层进行评价与预测。指出层序Ⅱ低位域的优质储层主要分布在安岳-南充-潼南-磨溪一带;层序Ⅲ低位域的八角场-西充-潼南-磨溪一带。优质储层发育于三角洲前缘亚相,成岩相类型主要为压实-绿泥石衬边-溶蚀-破裂成岩相。更多还原

【Abstract】 The reservoir of Xujiahe formation of the Upper Triassic clastic reservoir is one of the key stratum series in the western Sichuan foreland basin. Due to the pay formation was buried deeply and depressed for a long time, it is the reservoir with low porosity , low permeability and heterogeneous, which is very hard to explore. Therefore, it is necessary to make research into Xujiahe formation of the Upper Triassic reservoir characteristics.Based on the theories and technologies of sedimentology, reservoir geology, petrology, geochemistry and reservoir evaluation, researches are carried out on several aspects such as reservoir petrologic characteristics, reservoir sandbody genesis types and distribution characteristics, diagenesis type, reservoir pore types and evolution, physical property characteristics and its controlling factors. The results are as follows:(1) By the thin section observation, the analysis of the scanning electron microscope and the electron microprobe, it is thought reasonable that quartz direct dissolution exist in west Sichuan foreland basin of the Upper Triassic formation. The paper not only pointed out the area of quartz dissolution, analyzed the origion of alkaline fluid and the order of acidic and alkaline dissolution, but also quanized the effect of the alkaline dissolution to the reservoir characteristics.(2) By combination of diagenetic facies study with regional structural movement, depositional environment, fluid characteristics and provenance property, the paper proposed the effective study method of reservoir diagenetic facies. The diagenetic single factor of reservoirs was analyzed in the western Sichuan foreland basin of the Upper Triassic. This paper determined the comprehensive diagenetic facies by superimposing the single factor diagenetic facies. The relationship of diagenetic facies and reservoir physical property was established. The reservoir of the Upper Triassic in the western Sichuan foreland basin can be divided into six kinds of single diagenetic facies and eleven kinds of comprehensive diagenetic facies. The mainly diagenetic facies which effect the reservoir characteristics include lining chlorite facies, dissolution facies, fracture facies, compaction-pressolution facies, quartz secondary enlargement facies and carbonate cementation facies.(3) Based on the comprehensive analysis on the influence of structure, sequence– sedmient and diagenesis, worked out the chief controlling factors of reservoir property in different foreland structure: in thrust belts structure fracture were chief factor, in fore-deep fracture and diagenesis were necessary, in fore-slope the kinds of sand body were important,which were controled by sequence– sedmient and diagenesis, in fore-bulge sequence and sedmient were chief factors. The high quality reservoir mainly developed in fore-slope and fore-bulge belt.(4) In the end, the clastic reservoir evaluation and prediction were performed in the different tectonic zones and different sequences of the Upper Triassic in the western Sichuan foreland basin on the base of sedimentary facies distribution, diagenesis facies, reservoir evolution mode, pore and permeability distribution ichnographies. SequenceⅡLST high quality reservoirs developed in Anyue, Nanchong, Tongnan and Moxi structure, SequenceⅢLST high quality reservoirs developed in Bajiaochang, Xichong, Tongnan and Moxi structure. Good reservoirs developed in delta front subfacies, with the kind of diagenetic facies series of compaction-lining chlorite-dissolution-fracture facies.更多还原