【作者】 陈世松；

【导师】 徐国盛；

【作者基本信息】 成都理工大学 ， 矿产普查与勘探， 2010， 硕士

【摘要】 本人运用沉积学、石油地质学等理论知识,在分析前人研究成果的基础上,以大量的钻井、录井、岩心观察和岩心样品的多种试验资料为基础,探讨了苏码头构造中上侏罗统的沉积体系和沉积相类型、储层特征、地层水特征以及气水分布规律;深入分析了苏码头构造次生气藏高产井的控制因素。按照四川盆地中上侏罗统之地层特征及个组段的划分方案,将沙溪庙组分为三段,遂宁组分为两段,蓬莱镇组分为五段。据岩心观察、测井曲线分析,苏码头构造沙溪庙组主要为三角洲前缘沉积,部分为三角洲平原沉积;遂宁组主要是浅湖沉积,少量为三角洲沉积。蓬莱镇组主要为三角洲前缘沉积,小部分为三角洲平原沉积和浅湖沉积。苏码头构造蓬莱镇组主要发育长石岩屑砂岩,其次是岩屑石英砂岩和岩屑砂岩;遂宁组岩性主要为长石岩屑砂岩和岩屑砂岩。工区破坏性成岩作用包括压实作用、胶结作用、交代作用;建设性成岩作用包括早期环边伊利石(绿泥石的)形成和溶蚀作用;其中来自下伏的酸性流体导致的溶蚀作用是工区优质储层形成的主要因素。苏码头气田储层物性表现为低孔—低渗、特低孔—超低渗、高含水饱和度的“两低一高”的特点,储集空间由原生粒间孔和次生粒间孔组成,以原生孔与次生孔混合型为主,偶有微裂缝发育。根据录井、测井、地层水化学特征和测试资料,分析了苏码头气田蓬莱镇组、遂宁组和沙溪庙组地层水的成因及气水的微观、宏观分布特征。苏码头构造遂宁组和沙溪庙组位于较多的泥岩包裹之中储层内,封闭性较好,属于构造—岩性圈闭气藏。上覆的蓬莱镇组气藏埋深较浅,有的甚至处于大气水渗滤的地带,天然气的散失比较严重,保存条件较差。但是钻遇分布面广的泥岩下的较厚的砂体,往往也能形成较好的岩性圈闭,成为高产气藏。经研究发现苏码头气田地层封闭性和层位深浅有一定的相关性,即层位越深封闭性越好。苏码头构造上三叠统烃源岩为侏罗系天然气聚集提供了物质基础;相互叠置的砂体为气藏的形成提供了有利的储集条件;苏码头构造高产井主控因素归结为:①离断层较近的构造高部位有利于油气的聚集而含气丰度高;②相控下较厚泥岩下伏的优质砂体有利于油气的聚集与保存;③具有较厚的和较高孔渗性的砂体是高产气井出现的前提。更多还原

【Abstract】 I apply sedimentology and petroleum geology theory, basing on the analysis of previous studies, a large amount of drilling, logging, cores and core samples of a variety of experimental tests, the multi-direction complement, perfect combination of macro and micro methods, to analyse the Sumatou Middle-Upper Jurassic gas field in the sedimentary system and sedimentary facies, reservoir characteristics, formation water characteristics and gas and water distribution and gas accumulation pattern systematically. Meanwhile, I investigate the Terminal secondary reservoir gas wells yield controlling factors of the Sumatou structure.According to the characteristics of the Sichuan Basin in the Middle-Upper Jurassic strata and the classified scheme about each, we divide the Shaximiao formation into three sections, the Suining formation into two sections, and the Penglaizhen formation into five sections. Relying on the core observation, log analysis, the Shaximiao formation in the Sumatou gas fieldis mainly terminal area delta front depositions and part of it is the delta plain. While the Suining formation is mainly shallow lake deposition and a small quality of delta sediment. The Penglaizhen formation is mainly delta front and a small part of it is the delta plain and shallow lake deposits.Penglaizhen of Sumatou gas fieldregion formation is mainly feldspathic lithic sandstone, and secondly is the lithic quartz sandstone and lithic sandstone; Suining formation rocks are mainly feldspathic lithic sandstone and lithic sandstone. The destructive diagenesis of work area includes compaction, cementation and replacement; constructive diagenesis includes the formation and dissolution of early rim illite (chlorite); the dissolution of acid water formed by the mix of underlying hydrocarbon formation formed the main reservoir consisting of intergranular dissolved pore in the work area.The analysis of Core properties showed us that the gas reservoir properties of Sumatou gas field reflects low porosity - permeability, extremely low porosity - low permeability reservoir, high water saturation of the "two low and one high" features. The storage space was constituted by the original intergranular pore and secondary intergranular pores, which was mainly formed by primary and secondary bore hole and has micro-fracture occasionally.According to logging, characteristics of formation water chemistry and the test data, we analyse the the surface layer water in the Penglaizhen, Suining and Shaximiao formation of the micro and macro distribution of water causes. The study found the relativity between the closure of the Sumatou gas field and layer depth, that is, the deeper the layer, the better sealing.Sumatou structure of the Upper Triassic source rocks provided the material foundation for the Jurassic gas gathering; mutually superimposed sandy body supplied the favorable reservoir conditions for the formation of gas reservoir. The controlling factors of high-yield wells in Sumatou structure attributed to:①the high position closer to the fault is conducive to gas accumulation and gas abundance;②the sand under high-quality thick mudstone is conducive to hydrocarbon accumulation and preservation;③the sand body with thick and high porosity and permeability is the prerequisite for high-yield wells there.更多还原