贝西地区叠前、叠后联合反演及砂岩储层地震识别技术

【作者】 仵宗涛；

【导师】 唐书恒；

【作者基本信息】 中国地质大学（北京） ， 油气田开发工程， 2014， 博士

【摘要】 地震应用己经从构造形态深入到储层评价，地震研究也从宏观趋向微观，地震资料中所蕴含的岩性、物性信息也必须通过多种途径予以揭示。地震储层预测作为储层地球物理的一项核心技术，在这过程中起着极其重要的作用。贝尔凹陷霍12工区主要目的层南屯组沉积时期，盆地快速沉降，扇三角洲快速向湖盆推进，形成扇三角洲—湖泊充填期，储层岩性主要以粉砂岩为主，储层与非储层的波阻抗差异较小，常规反演技术很难区分有利储层；箕状断陷的斜坡带相变快、地层薄、埋深大、物性差、产能低、含油气储层预测难度大；储层垂向相对较为发育，但单层厚度较薄，受地震分辨率影响，单砂层预测非常困难；同时受围岩等影响，岩石物理敏感参数选择非常困难。针对这些技术难点，如何最大限度地挖掘地震资料的信息，采用了7大关键技术：波阻抗反演、去压实效应、拓频高分辨处理、地质统计学反演、分频物性反演、吸收衰减分析、LithSI流体概率预测，形成了适合本区地质特点的岩性、物性以及流体预测三大技术研究流程。和以往储层预测工作相比，有以下三大创新：（1）将叠后波阻抗反演技术、拓频高分辨处理、去压实效应以及地质统计学技术进行有机融合逐级提高砂岩预测精度。（2）首次利用叠前反演结果和分频反演技术结合在本区开展了孔隙度物性反演。（3）尝试利用新一代Lithsi岩性流体概率预测技术用于流体检测。更多还原

【Abstract】 Seismic studies have been deepened into reservoir evaluations from geological structures.Seismic studies are also from macro to micro. Lithological characters and physical propertiesin seismic data must be revealed through variety ways. Reservoir prediction using seismic is acore technology in reservoir geophysics, which is extremely important in the process. Whilethe major reservoir Nantun in Huo12survey was deposited, the Beier Depression was rapidsubsidence and a fan-delta moving into the lake. Reservoirs are mainly siltstone. Reservoirsand non-reservoirs difference in impedance is small. It is difficult to detect reservoirs usingconventional inversions. Slopes of a half graben with phase changing fast, thin horizons,large depths, poor physical properties, low productivities, hydrocarbon reservoir prediction isdifficult. Reservoirs have many layers in a vertical direction, each layer is thin. The thinsandstones are very difficult to predict because of seismic resolutions. Simultaneouslyaffected by surrounding rocks, rock physics sensitive parameter selection is very difficult. Inresponse to these technical difficulties, making full use of seismic data, we used the seven keytechnologies: impedance inversion, elimination compaction effect, high frequency resolutionprocessing, geostatistical inversion, decomposing frequency and physical propertiesinversion, attenuation analysis, LithSI fluid probability forecast. We form three predictionworkflows that are suitable for geological characteristics of the area’s lithology, physicalproperties and fluid. Comparing to previous work and reservoir predictions, we achieve threemajor innovations:(1) the post-stack impedance inversion, high frequency resolutionprocessing, elimination compaction effect and geostatistical inversion are integratedstep-by-step to improve forecasting accuracy in sandstones.(2) The pre-stack inversion andthe decomposing frequency inversion are combined in the region to carry out the physicalproperties of porosity inversion.(3) The new generation LithSI lithology and fluid probabilityprediction techniques are used for fluid forecast.更多还原