【作者】 杨克文；

【导师】 李文厚；

【作者基本信息】 西北大学 ， 油气田地质与开发， 2009， 博士

【摘要】 本文在充分掌握、收集研究区区域地质资料和前人研究成果的基础上,以沉积学的基本原理和方法为指导,进行野外露头观测,结合钻井、岩心、测井、地震等资料,综合构造、地层、储层地质学、地球化学、盆地分析等理论和方法,对安塞油田长4+5油层组的沉积体系发育、展布特征和砂体分布特征进行了深入研究。较为详尽地查明了研究区含油气情况,分析了不同层段的含油气性特征,评价了研究区长4+5油层组的有利勘探区域,了解了含油气规模及其勘探前景。同时全面地整理了地质、分析化验、测井、测试等资料和数据,系统分析了长4+5油层组有利储集体的展布和沉积相与油气分布的关系。研究区主要为湖泊、三角洲沉积模式,大部分地区为三角洲前缘沉积,砂体均呈北东-南西向条带状展布。研究区东北部地区为三角洲平原沉积,长4+5₂的浅湖面积大,仅在东北部存在少量的三角洲平原,而长4+5₁东北部的三角洲平原相面积稍大些。三角洲前缘水下分流河道及平原分流河道是重要的油气储集体。研究区内长4+5储层的岩石类型主要为长石砂岩或岩屑质长石砂岩。胶结物类型复杂多样,其中以绿泥石、方解石最为重要。安塞油田长4+5储集层砂岩具有矿物成熟度低、结构成熟度高的特征。长石等溶蚀孔占总面孔率较大,成为长4+5的相对优质储层。成岩矿物主要为薄膜状绿泥石及加大状石英质矿物,还有自生磷灰石、充填状硅质及碳酸盐矿物。安塞油田长4+5油层组主要为岩性和构造-岩性复合式油气藏,其中以岩性油气藏为主。长4+5₂以砂岩上倾致密遮挡和上倾尖灭为主的岩性油气藏为主。油藏的分布受沉积作用、生油中心、有利储集相、生储盖有利配置、鼻隆及上倾方向遮挡的控制。研究区长4+5₂为长4+5油层组的主要含油层段,有利区主要分布在杏河、坪桥及安塞沿河湾地区,这些区域电测物性较好,具备一定的成藏条件,为长4+5₂油层组下一步的勘探目标,西河口-高桥为次要有利区;研究区长4+5₁油层组整体的含油性较差,油气显示好的区域面积少,塞80井区为长4+5₁较有利区,谭家营、坪桥、杏河、西河口-高桥地区为次有利区。总体上看,长4+5₂的油气显示情况好于长4+5₁。更多还原

【Abstract】 This paper lucubrates about the sedimentary system development and distributing feature and sandbody distributing features of Chang 4+5 oil formation in Ansai Oilfield, finds hydrocarbon condition at large, analyses and estimates hydrocarbon-bearing characteristics in different stratum and favorable exploration area, finds out petroleum scale and exploration prospects on the basis of gripping investigation areal geological data and digestion and absorption of previous research results. This conclusion is directed by sedimentary theory and methods integrating with theories of technical , stratum, reservoir geology , geochemistry , basin analysis and data of outcrop , drilling , well logging. Meanwhile, the study gets the general geology, analysis assay, well logging and test data, predicts the relation of sedimentary facies and petroleum distribution and the distribution of favorable reservoir of Chang 4+5 oil formation.The study area mainly includes lake and delta sedimentary model, most areas are delta front deposits, and sandbody all show NE-SW banding distribution. The northeast part of study region is deltaplain deposits , shallow lake of Chang 4+5₂ has large scale , only in northeast part there are a spot of deltaplain, while the deltaplain acreage in same part of Chang 4+5₂ is slightly larger. In this part, channel sandbars, deltaic front subaqueous distributary channel and deltaic plain distributary channel are main reservoir bodies.The rock types of Chang 4+5 in this region are mostly arkose or lithic arkose sandstone. Cement types are complicated and various, which are mainly chlorite and calcite. Reservoir sandstone of Chang 4+5 in Ansai oilfield has features as low maturity of mineral and high textural maturity. Dissolve pores of feldspar and so on have high ratio of total pore amount and become relative high quality reservoir of Chang 4+5. Diagenetic minerals are mainly thin film shaped chlorite and increasing shaped quartz minerals. There are autogenous apatites, filled silicious and carbonate minerals as well.Chang 4+5 oil formation in Ansai oilfield is mainly lithology and structure-lithology combination reservoir, in which lithology reservoir is the main part. Chang 4+5₂ formation is mostly composed of lithology reservoir which mainly composed by sandstone undig finely barrier and updig pinch. The distribution of reservoir is controlled by sedimentary processes, source-reservoir-cap favorable assemblage, oil-generating center, favorable reservoif phase, and nose structure and updig direction favorable occlusion. Chang 4+5₂ in the region is main oil-bearing horizon of Chang 4+5 formation, favorable area mainly distributes around Xinghe, Pingqiao, Ansai Yanhewan , where electrical measurement and physical properties are better and have certain reservoir forming conditions, thus , become next exploration target of Chang 4+5₂ . Xihekou-Gaoqiao region is the minor favorable area; Oiliness of Chang 4+5₁ formation in the region is poor as a whole , the area that oil-gas has better show is limited , Sai 80 well field is the more favorable area of Chang 4+5₁ formation, Tanjiaying, Pingqiao, Xinghe, Xihekou-Gaoqiao region are minor favorable area. In general, Chang 4+5₂ oil-gas show is better than Chang 4+5₁.更多还原