【作者】 王建民；

【导师】 任战利；

【作者基本信息】 西北大学 ， 油气田地质与开发， 2011， 博士

【摘要】 本文密切结合勘探实际,以鄂尔多斯盆地东部奥陶系风化壳为对象,以多学科地质理论与技术方法为指导,充分利用钻井、测井、录井显示、岩心观察、实验分析、试采成果、二维地震等资料,将地质与地震方法密切结合,对风化壳古地貌及其岩溶储层特征进行了深入的研究。通过对风化壳侵蚀面上下之目的层段地层的精细划分对比,建立了全区地层格架,总结了地层特征；查明了风化壳地层残存状况；落实了风化壳上下地层的今构造特征及古构造演化特点,分析了风化壳发育层段地层沉积环境条件、概括了其沉积相类型、沉积特征及岩矿组合。结合古生界地质构造演化特征,深入探讨了奥陶系风化壳古地貌恢复的方法思路,确定了古地貌单元属性判别的依据和原则,建立了划分解释古地貌单元的综合地质模型以及地震解释模型；探索了古地貌恢复的新方法。分别运用“印模法”、“残厚法”对风化壳古地貌进行了初步恢复,在此基础上将“印模法”与“残厚法”结果以及地质与地震手段相结合,运用“综合法”最终完成了风化壳古地貌的恢复研究。在此基础上,以岩心观察和测井资料为依据,对风化壳水动力以及岩石学分带特征进行了划分和论述；建立了盆地东部古岩溶发育模式；依据古地貌单元对岩溶储层的岩石学特征、物性特征、古岩溶作用、孔洞缝系统等进行了详细的分层论述和综合评价,总结了岩溶储层发育的主要控制因素；预测了古岩溶有利区带。研究结果表明,盆地东部奥陶系风化壳发育层段地层保存较为完整,其顶部发育马六段灰岩,底板为马五5黑灰岩,其间为陆表海碳酸盐台地潮上及潮间亚相沉积,白云岩发育,岩溶储层基础较好；区域主力含气层段马五1残存较多,分布广泛。古地貌基本处于岩溶斜坡和岩溶盆地发育区内,可进一步识别并划分出残丘、台地、台缘、阶坪、沟谷、洼地等十二个三级古地貌单元。古岩溶作用强烈；岩溶储层主要为特低孔超低渗的双孔介质储层,其发育程度主要受相带、岩性、成岩作用、古地貌等因素控制；斜坡台缘及斜坡阶坪发育区是本区风化壳岩溶储层发育的最有利部位；孔渗平面分布具“三高两低”特点；综合确定了三个岩溶储层发育的有利区带。更多还原

【Abstract】 This paper made in-depth research of the weathering crust paleogeomorphology and karst reservoir characteristics,by closely combined with the actual exploration, of ordovician weathered crust for object in eastern Ordos Basin,,with multidisciplinary geological theory and technology for guidance, made full use of drilling well logging and logging display, core observation, experimental analysis, the production test results,two-dimensional seismic data,etc, combined the geological methods with seismic methods closely. Set up the regional stratigraphic framework, summarized the stratigraphic characteristics; found out the remaining status of weathered crust strata; Implemented the current tectonic characteristics and ancient tectonic evolution characteristics of fluctuation strata of the weathered crust; analyzed stratum depositional environment conditions of the weathered crust development layer segment, summarized types of their sedimentary facies,sedimentary characteristics and rock assemblage, through fine stratigraphic division and correlation of the objective interval that located above and below erosion surface. Combined with the evolution characteristics of palaeozoic geological structure, deeply discussed methods and ideas of paleogeomorphology restoration about Ordovician weathered crust, determined the basis and the principle that distinguished palaeogeomorphology unit attribute, established comprehensive geological model and seismic interpretation model of dividing and interpretting palaeogeomorphology units; explored the new methods of paleogeomorphology restoration. Made preliminary recovery of the weathered crust palaeogeomorphology by using respectively the "Impression method" and "residual thick method" based on these, combined results of the "Stamping method"and" Residual thick method" with the geological and seismic methods,and, eventually completed recovery research of the weathered crust palaeogeomorphology by using "synthesis method". On that basis, according to core observation and well logging data, divided and discusses characteristics of hydrodynamic force and petrology zonation of weathered crust; established ancient karst development model in the basin east; made the detailed layering discussion and comprehensive assessment on the petrology characteristic, physical property characteristics, ancient karstification, and bore-hole-split system of the karst reservoir according to the palaeogeomorphology units;summarized the major controlling factors of the karst reservoir development; foretasted favorable zones of the ancient karst.The results show that the stratum sequence preservation of the Ordovician weathered crust development layer segment was quite completely in the basin east, developed the Ma6 segment limestone on it’s top, and it’s bottom board was Ma55 black limestone;those stratum between its belong to supratidal and intertidal subfacies sedimentation of the continental sea carbonate tableland, there are developmenal dolostone.and a better karst reservoir foundation; Ma51layer segment that is a regional main gas bearing layer had more residual thickness,and wide distribution. Paleogeomorphology of the researched area basically is located in the developmental area of the karst slope and karst basin,can be further identified and divided into 12 sort three-level paleogeomorphology units,such as monadnock,tablelands,tableland tableland margin,steps level ground,cheuch and depression,etc. Ancient karstification intense; the karst reservoir mainly belongs to double porosity media reservoir with the extra-low to ultra-low porosity and permeability, it’s development degree was mainly controlled by the phase belt, lithologic character, diagenesis, paleogeomorphology and other factors. The development areas of tableland margin and steps level ground in karst slope are optimum places of the weathered crust reservoir in this area;he plane distribution of the porosity and permeability have the characteristics with "three high and "two low";synthetically determined three favorable zones of the karst reservoir development.更多还原