【作者】 黄进腊；

【导师】 孙卫；

【作者基本信息】 西北大学 ， 油气田地质与开发， 2011， 博士

【摘要】 鄂尔多斯盆地靖边气田奥陶系马家沟组马五段是最有利的气藏层系之一,由于马五段主力储层深度大、厚度薄、非均质性强等原因,直井开发产能较低,为了提高单井产量和采收率,提出采用水平井开发的思路,但是靖边气田在水平井设计部署和实施的过程中,井间小幅度构造制约了水平井的现场导向能力,本文综合应用钻井、测井和地震数据,以陕190井区和陕200井区为解剖点,对研究区内的小幅度构造特征进行了识别、描述、分析和研究,得到了相关认识,为靖边气田的水平井设计部署和实施提供了一定的理论指导和开发建议。(1)在对研究区153口井的石炭系本溪组、奥陶系马五段进行小层精细划分、对比的基础上,绘制35条对比剖面和35条气藏剖面,结合42条二维地震剖面层位标定、层位追踪的分析研究和时深转换,编制了研究区储层的小幅度构造图。研究区马五段储层褶皱变形为低幅度、断续褶皱,构造样式主要有鼻状构造、穹形和盆形构造,以鼻状构造为主,褶皱十分微弱,褶皱以NE-NEE向为主,属于稳定克拉通地块的构造样式。(2)利用地震正演模拟了4种奥陶系顶部不同侵蚀程度的沟槽地震波形响应特征：①未侵蚀型②下凹型③下凹复波型④上超+削截型,为侵蚀沟槽的识别提供了重要的理论指导和参考依据。陕190井区发育了2条主沟槽,主体呈北西-南东向成排分布；陕200井区发育了6条主沟槽和若干条支沟槽,主沟槽多呈近东西向。(3)综合利用残余厚度法和印模法综合分析研究古地貌,恢复了研究区奥陶纪末期古地貌,古地貌主要表现为三种类型：岩溶台地、岩溶斜坡及岩溶沟槽；古地貌中岩溶沟槽的展布特征,对马五段天然气的富集程度起着重要的控制作用。(4)对小幅度构造进行识别、描述、分析的基础上,将鼻状构造之间的组合类型归纳为五类。对研究区内构造、地层、岩溶古地貌与天然气的富集关系综合分析研究后,将区块内圈闭归纳为二大类七亚类,认为古地貌-地层-构造复合圈闭是研究区块内天然气主要富集类型。古侵蚀沟槽旁侧有利构造是天然气富集空间,为今后布置高产井位提供了地质依据。(5)研究区已完钻的两口高产水平井水平段钻进轨迹与目的层小幅度构造起伏相关系数R2分别为0.6548和0.8647,相关性较好。(6)对研究区天然气富集规律进行综合分析研究的基础上,建议有利靶点14处。更多还原

【Abstract】 The Mawu segment of Majiagou formation in Ordovician is one of the favorable series of stratum in Jingbian gas field, Ordos basin. As the main reservoir Mawu13 layer in Mawu segment is depth, thin and strong heterogeneity and so on, vertical well developments have lower productivity. In order to improve the well production and recovery, the idea of using horizontal wells are proposed. However, low-amplitude structure in cross-well restricts capacity of horizontal wells on-site orientation in the process of design, deployment and implementation for horizontal well in Jingbian gas field. Based on the seismic explanation and logging and drilling data, the paper studies, describes and analyses the characteristic of low-amplitude structure, taking Shaan 190 and Shaan 200 well areas for example. This study arrives at the following conclusions in the hope of providing theoretical guidelines and development suggestions for the design and deployment and implementation of horizontal wells in Jingbian gas field.(1) Based on the fine subdivision and correlation of the Benxi Formation of Carboniferous and Mawu formation of Ordovician of 153 well, the 35 comparison sections and 35 gas reservoir profiles are mapped. Combined the study of horizon calibration, horizon track and time-depth conversion, the low-amplitude structures of reservoirs are mapped. Fold deformation in the study area is low amplitude and intermittent fold. Structural styles mainly include nose structure, dome and basin structure, but fold is very weak, mainly to nose structure and NE-NEE direction. It is stable craton block structural style.(2) The character of seismic wave for ancient valleys in different degree of erosion are forward modeling, including①not eroded type②the concave type③concave-complex wave type④onlap&erosional truncation type. These works provides an important theoretical guidance and reference for the identification of the ancient valleys. The two ancient valleys have developed in shan190 well area, which are the main NW-SE direction distribution rows. The six ancient valleys and some sub-ancient valleys have developed in shan200 well area, which are the main E-W direction distribution. The sub-ancient valleys are NE-SW or NW-SE direction distribution.(3) The methods of residual thickness and impression method are used to recover the paleogeomorphic features of the Ordovician. The paleokarst landform types are divided into 3 categories, including karst platform, karst slope and karst valleys. The karst valleys play an important role in controlling the degree of natural gas enrichment of the Mawu segment.(4) Based on the comprehensive analysis of the low-amplitude structure, the combination types of nose structure are summed up 5 categories. Traps are divided into 2 categories and 7 sub-categories after the study with the relationships between gas enrichment and structure, formation, karst topography. The combination trap with ancient landform-formation-structure is the mainly type of natural gas enrichment. The favorable structure of side of ancient valleys provides geology evidence for arrangement well in the future.(5) The correlation coefficients of the relationship between horizontal section drilling track of the two high-yielding horizontal wells and the low-amplitude structure for objective layer are better, because R2 are 0.6548 and 0.8647.(6) Based on the comprehensive analysis of the relationships of between gas enrichment and low-amplitude structure, ordovician paleokarst landform, ancient valleys, thickness of Mawu1+2, and thickness of Mawu13 as main gas layer,14 favorable targets are recommended.更多还原