【作者】 董桂玉；

【导师】 陈洪德；

【作者基本信息】 成都理工大学 ， 沉积学， 2009， 博士

【摘要】 本论文运用沉积学、高分辨率层序地层学、储层地质学、矿物岩石学、地球化学、地球物理学、石油地质学以及储层评价等理论和技术方法,充分利用岩心、露头、录井、测井和地震资料,在前人研究成果的基础上,以“盆地演化-沉积层序演化-有效储集砂体展布规律”为主线,按照“五步流程+图表定砂体”的岩性油气藏有效储集砂体预测的评价程序,系统研究了苏里格气田上古生界气藏主力含气层段(山1段、盒8段)有效储集砂体的展布规律,取得了如下创新性成果和认识:①按照“宏观控局+微观定区”的研究思路,通过研究阴山古陆和伊盟隆起的构造演化,并对比分析物源区基岩与盆内沉积物的响应关系,首次明确了二者对研究区沉积物供给的影响。结合Dickinson三角投点图、基岩分布特征、碎屑组分特征、重矿物分布特征、岩屑特征、石英阴极发光特征、稀土元素特征和碎屑锆石定年等方法、手段,揭示了苏里格气田上古生界主力含气层段沉积时期的物源供给区是阴山古陆。②在物源分析的基础上,按照“单井相-连井相-平面相-沉积演化-沉积模式”的研究流程,结合鄂尔多斯盆地上古生界的宏观沉积背景,根据盆地演化和浅水三角洲的形成机制,确认苏里格气田在山1段、盒8段沉积时期,发育浅水三角洲沉积体系,首次提出了苏里格气田盒8段的沉积环境为“毯式浅水辫状河三角洲”的概念,并首次建立了指导苏里格气田储层评价和预测的浅水曲流河三角洲沉积模式(山1段)和毯式浅水辫状河三角洲沉积模式(盒8段)。③依据以Cross的基准面旋回为指导思想的高分辨率层序地层学理论和方法,结合苏里格气田主力含气层段(山1段、盒8段)已有的地层划分方案,系统研究了主力含气层段的层序特征、层序结构,建立了地震层序格架和以中期旋回为等时对比单元的高精度层序地层格架。明确了层序格架中大多数长期旋回层序具有区域性湖进-湖退沉积旋回性质,以长期旋回层序为单位,储集砂体的发育可分为2种类型,其一发育于层序分界面两侧,其二发育于层序内,发育于界面两侧的砂体产出层位相对较稳定,厚度较大,垂向上连续叠置,侧向上呈相互重叠的连通的毯状或宽带状展布,是储集砂体最为发育的位置;无论是平行或垂直物源供给方向,随着可容纳空间的增加,每个中期旋回层序的厚度,特别是洪漫细粒沉积的厚度,具有同步增厚,而储集砂体厚度和发育位置出现反向的退缩和减薄的变化趋势(局部地区受古地形影响有所增厚或减薄)。④通过系统研究储层岩石学特征、成岩特征、物性特征、孔隙结构特征、非均质性特征和储集砂体成因类型等,确立了储层评价参数和标准,进行了储层分类评价和综合评价。其中,未实施压裂改造的条件下即可获得中高产能的Ⅰ类储层和压裂后可获中高产工业气流的Ⅱ类储层主要分布在研究区的盒8段,部分Ⅱ类储层分布山1段,压裂改造后有可能获得工业气流的Ⅲ类储层和Ⅳ类非储层在山1段和盒8段均有分布。⑤在上述研究工作的基础上,重点结合有效储集砂体沉积特征、层序地层学特征和储层综合评价结果,参考有效储集砂体的主控因素,明确了苏里格气田上古生界山1段、盒8段有效储集砂体的展布规律。其中,山1段砂体为带状分布,有效储集砂体为孤立状分布;盒8段砂体呈大面积毯式分布,有效储集砂体多呈孤立状分布或局部地区呈带状分布。相对富集区块分布在主(辫状)分流河道砂体范围内,其中Ⅰ类区块(有利区)和Ⅱ类区块(较有利区)应该是下一步勘探的重点地区,Ⅲ类区块(中等有利区)也有很重要的经济开采价值。更多还原

【Abstract】 According to the theory and methods of Sedimentology, high-resolution sequence stratigraphy, reservoir geology, mineralogy, geochemistry, geophysical, petroleum geology and reservoir evaluation, taking full advantage of data of core, outcrop, logging and seismic, on the basis of predecessor’s achievements, along the main line of basin evolution, sedimentary evolution and distribution regulation of effective reservoir sandbody, and according the evaluation process of prediction on effective reservoir sandbody of lithology reservoir, which is five-step and block decided by graphic and table, distribution regulation of effective reservoir sandbody of major gas-bearing interval in Sulige gas field was studied systematically, several creative achievements as follow were obtained.①According to research idea of provenance direction controlled by tectonism and provenance location determined by analysis and measurement, based on the study on tectonic evolution of Yinshang old land and Yimeng upheave and the analysis of the response between provenance basement and sediment in basin, the influence on sediment supply in study area by both was definited firstly. With combination of Dickinson triangular diagram, distribution character of basement rock type, detrital component character, heavy mineral distribution character, rock detrital character, quartz cathodeluminescence character, REE character and Zircon dating, it is revealed that the provenance of upper Paleozoic major gas-bearing interval in Sulige gas field was from Yinshang old land.②Based on provenance analysis, according to the research route of single well facies, cross-well facies, plane facies, sedimentary evolution and sedimentary model, with combination of sedimentary setting of upper Paleozoic in Ordos basin, and according to basin evolution and formation mechanism of shallow water delta, it is concluded that shallow water delta system developed in Sulige gas field during period of Shan1 and He8. It is first proposed that the sedimentary environment is blanketed shallow water braided river delta in He8 member of Sulige gas field, and the sedimentary model of shallow water meandering river delta in Shan1 member and the model of blanketed shallow water braided river delta in He8 member were built firstly, which were used to guide reservoir evaluation and prediction in Sulige gas field.③According to the theory and methods of high-resolution sequence stratigraphy, which is guided by the Cross’s base level cycle, with combination of stratigraphy classification plan of major gas-bearing interval in Sulige gas field, sequence character and sequence configuration of major gas-bearing interval were studied carefully, seismic framework and high-resolution sequence stratigraphy framework of mid-term cycle were built. It is clear that there are regional progressive and regressive cycles in most long-term cycle of sequence framework, two types of reservoir sandbody developed in the long-term cycle, one of them developed on two sides of sequence boundary, the other one developed within sequence. The position of sandbody developed on sides of sequence is relatively stable, the thickness is great, they usually stacked continuously in vertical direction, and they stacked in shape of blanket or wide belt in horizon direction, where are the best position for developing reservoir sandbody. No matter the supply in horizon or vertical, with the increase of accommodation, the thickness in every mid-term cycle, especially the thickness of fine flooding sediment increased synchronously, meanwhile, the thickness of reservoir sandbody and the developing position showed reverse regression and reduction, part of them were affected by paleotopography.④Based on the systematical study on character of reservoir mineralogy, diagenesis, geophysical, pore configuration, nonhomogeneity and reservoir sandbody genetic type, parameter and standard of reservoir evaluation are established to evaluate by sorting and synthetically. TypeⅠreservoir with high production without any fracturing and typeⅡreservoir with high industrial gas flow after fracturing mainly located in He8 member, part of typeⅡlocated in Shan1 member, typeⅢreservoir and typeⅣnon-reservoir with industrial gas flow after fracturing can be both found in Shan1 and He8 member.⑤Based on the forenamed studies, particularly combined with results of sedimentary character of effective reservoir, sequence stratigraphy character and reservoir evaluation, referenced the main control factors of effective reservoir, the distribution regulation of effective reservoir of Shan1 and He8 member of upper Paleozoic in Sulige gas field is explicit. The sandbody of Shan1 member distributed in shape of belt, effective reservoir sandbody distributed isolatedly, the ones of He8 member distributed in large area like blanket, effective ones mostly distributed isolatedly or regionally in shape of belt. Respectively enrichment blocks located in sandbody of main braided distributary channel, the most favorable typeⅠblocks and second most favorable typeⅡblocks should be key area for next exploration, the middle favorable typeⅢblocks also have high value for exploration.更多还原