电阻率约束下的地震反演技术在库车某区叠前深度偏移速度建场中的应用  

Application of resistivity constrained seismic inversion technique in building pre-stack depth migration velocity field in Kuqa depression

作　　者：冯许魁 熊兴银 刘永雷 谷永兴 

机构地区：[1]中国石油东方地球物理勘探有限公司,新疆库尔勒841001

出　　处：《地球物理学进展》2016年第1期170-176,共7页Progress in Geophysics

摘　　要：库车山前带发育第四系和新近系两套砾岩,第四系砾岩主要发育于冲积平原沉积体系,新近系砾岩主要发育于冲积扇沉积体系.不同时期不同沉积体系下的砾岩组合在一起表现为垂向上具有多期叠置性,横向上沉积范围局限具有不连续性.空间岩性的巨大变化给库车山前带的精细速度建场带来很大困难,导致构造落实非常困难.非地震电阻率数据能够清晰反映两套砾岩层的空间轮廓分布特征,测井数据能够反映砾岩垂向的多期叠置特征,地震数据不能反映砾岩的形态特征,但是能够反映正常地层的格架特征.通过把地震数据与电阻率数据进行融合,在融合体上进行联合构造解释,建立了不同岩性的精细层序地层格架模型,利用此模型对地震波阻抗反演进行约束,反演得到纵波速度体.利用该速度体作为叠前深度偏移处理的初始速度模型,通过反复迭代,建立了最终的叠前深度偏移速度场,较为可靠的落实了库车地区的圈闭形态、高点位置和埋深.There are two conglomerate strata developed in the Kuqa Depression,which include the Quaternary conglomerate formation developed in alluvial plain sedimentary system and the Neogene conglomerate formation developed in alluvial fan sedimentary system. The conglomerate sets are obviously characterized by vertical superimposition and lateral discontinuity. However, the spatial variation of lithology has brought many great problems to accurately building velocity field in Kuqa thrust fault belt and made it very hard to implement traps. Non-seismic resistivity data can effectively reflect the spatial configuration of the two conglomerate strata,and well logging data can disclose the multi-period overlaying conglomerate strata clearly. Although seismic data cannot shows distribution shapes of conglomerate strata, it can reveal the stratigraphic framework. Through integrating the resistivity data and seismic data,we obtained a mixed data. Based on the mixed data,comprehensive structural interpretations was conducted and elaborate sequence stratigraphic framework model was built to constrain seismic inversion to receive a P-velocity data used as an primary velocity model for pre-stack depth migration process. By repeated iteration analysis,pre-stack depth migration velocity field was erected finally,which could be used to implement the structure shape,structure highness and buried depth of the traps reliably in Kuqa thrust fault belt.

关 键 词：电阻率数据 地震数据 层序地层格架模型 波阻抗反演 初始速度模型 

分 类 号：P631[天文地球—地质矿产勘探]