高密度宽方位地震勘探是现阶段油气勘探的主要方向之一,作为面向高密度宽方位地震数据处理的OVT域处理技术也得到了快速发展,特别是时间域的OVT处理,其基本流程、方法已较为成熟,但如何做好OVT处理每一个流程节点的质量控制工作,目前业界还没有形成较为完整、统一的质量控制标准.以时间域OVT处理流程为主线,首先介绍了目前通用的时间域OVT处理流程,包括OVT域道集分选、OVT道集细分、OVT域插值、OVT域叠前时间偏移以及OVT道集的速度方位各向异性校正;然后,基于OVT域的通用处理流程,详细论述了时间域OVT处理的质量控制手段,主要包括OVT道集的空间分布、方位角偏移距属性、OVT道集单次记录、OVT道集单次偏移、OVT道集显示、OVT道集偏移距-振幅属性等.四川盆地TNB探区实际应用结果表明,系统的OVT域处理质量控制可以提升时间域OVT的处理效果.时间域OVT处理质量控制方法研究加快了现阶段的OVT域处理技术的推广应用.

OVT域处理技术是当前地震资料处理和解释的研究热点之一,OVT域的处理效果与OVT片尺度息息相关,而OVT片尺度取决于炮线距和检波线距.但现阶段地震资料,特别是老地震资料,其炮线距和接收线距较大(300～400 m),导致OVT片尺度较大,使得单片OVT数据的偏移距方位角属性一致性降低,从而影响了最终OVT域的处理效果.研究了减小OVT片尺度的处理技术,首先采用基于五维插值的检波线加密技术,加密一倍检波线,将炮线方向的尺度减小一半;然后在OVT片划分阶段,基于OVT域数据的互换原理,采用对折法优化OVT片划分,将检波线方向的尺度减小一半,最终达到将OVT片尺度减小一倍的目的.OVT道集内偏移距和方位角范围的减小,提高了OVT道集偏移距和方位角属性的一致性,改善了OVT域处理效果.实际应用结果表明:通过减小OVT片的尺度,达到减小OVT片的偏移距和方位角范围的目的,使叠前时间偏移效果得到有效改善,剖面的方位各向异性校正效果得到明显提升.

随着高性能计算机技术的快速发展和"两宽一高"采集技术的广泛应用,高分辨率、高保真的反演成像成为研究热点.首先从Bayes估计理论框架下的地震波反演成像出发,指出Bayes估计理论是地震波反演成像的基础,基于所选择波场预测器(一般为常密度标量声波方程)的波场预测残差的先验概率分布和要反演的模型参数的先验概率分布决定了模型参数的后验概率密度,后验概率密度的最大化是地震波反演成像最佳解的判定准则.在波场预测器为线性、预测误差为高斯白噪情况下,Bayes估计可在最小二乘意义下实现,并可以得到无偏和方差最小的参数估计结果.实际数据的不完备、线性化的正问题不能很好地模拟数据中的地震波场,使得数据协方差阵和模型协方差阵的引入成为必然.鉴于模型参数的正则化在反演成像中已有充分的讨论,重点讨论了加权最小二乘反演成像框架下数据协方差(逆)算子的作用,说明了数据加权处理在叠前深度偏移中的必要性.在将加权系数矩阵视为对角矩阵的基础上,提出了采用倾角扫描和动态时间规整算法确定数据加权系数,并将其应用于叠前深度偏移成像中.理论和实际数据的数值实验结果表明数据协方差(逆)算子能够有效提高偏移成像质量.

Dongpu Depression is geologically characterized by deeply-buried targets, complex fracture systems and thin beds. In order to accurately depict complex subsurface fracture system, we have conducted prestack migration imaging approach including prestack data regularization, high density automatic velocity picking, anisotropic migration and curved ray migration etc. Based on high density 3D seismic data, this approach improves greatly 3D seismic data imaging, and provides reliable final results for future exploration and development.

东濮凹陷的主要地震、地质特点是目的层埋藏深、断裂体系复杂、储集层单层厚度薄.为了提高勘探、开发效益,精确刻画地下复杂断裂体系,结合东濮高精度三维地震资料的特点,开展了叠前数据规则化、高密度自动速度拾取、各向异性偏移和弯曲射线偏移等技术研究,形成了一套适用于东濮凹陷复杂断块区的高精度三维地震资料叠前偏移关键技术,有效地提高了高精度三维地震资料的品质和成像精度,为勘探、开发提供了可靠的地震成果资料.

The structures in Pucheng-Weicheng area of Dongpu sag are complicated and the exploration mainly focuses on the crushing complex fault blocks and lithologic hydrocarbon reservoirs,such as the fault of the narrow space between two adjacent things,and the small fault blocks.The working area features in large-volume seismic data,complex wave field,and interference wave develops.In view of the characteristics of high-precision seismic data of Pucheng-Weicheng area and geological characteristics of the working area,research has been conducted on the fine processing method and high precision seismic imaging technology.High-precision seismic data processing technologies taking high-precision point-to-point velocity analysis,tomographic inversion static correction,prestack time migration,and prestack interference wave suppression as main features are developed.And obvious progress has been made in data processing.

To enhance the imaging precision of complex fault blocks and carry on fine description of small complex fault blocks,the key is to increase the density and precision of velocity analysis.Through actual data processing analysis,2% of the imgration velocity error will exert obvious effect on the intended interval migration imaging results during the application of prestack time migration to imaging of complex fault blocks.Therefore,improving the accuracy of velocity analysis is the key to high-precision seismic imaging.The conventional velocity analysis method is used hyperbolic NMO formula to carry on velocity analysis,and manual pick-up velocity is needed to be used.So the density is restricted,the quality of velocity analysis is also influenced by human factors greatly.In addition,as a result of the anisotropic characteristics underground media,reflecting the travel time is no longer a hyperbola,the application of conventional hyperbolic NMO may lead to uneven correction in the far-offset.In is paper,the high-density anisotropic velocity analysis method is proposed to be used.High-density automatic velocity analysis may be conducted,so non-hyperbolic NMO problems caused by anisotropy could be solved.

一、胜利油田油气资产概述 油气资产是指石油企业各采油气区块的油气井和相关的施工设备.具体包括:油、气生产井、注水井等;联合站、计量站、注水站、压气站等油气集输设施;集输油气水管线;油气处理设施等等.经过40多年的开发建设,胜利油田已发展成为年生产原油2600多万吨,生产天然气8亿立方米的国有特大型石油企业.现自有资产规模达1100多亿元,其中油气资产960亿元,占总资产的87%.油气资产在石油企业中占据重要的地位,其管理的好坏直接影响到石油企业的经济效益.它为油田企业的持续经营提供了保证,是油气资源勘探、开发、开采的主要生产物资,而且油气资产质量、技术的好坏直接影响石油天然气的提升、收集、处理和储存,进而影响石油天然气的采油率、生产量、产品质量、销售额以及生产成本.

Degradation in the quality of migration images can arise because of alias during Kirchhoff 3-D migration. Aiming at this phenomenon, operator anti-aliasing was discussed. The main method is firstly to derive the relevant operator aliasing criteria and then present our efficient method of anti-aliasing the migration operator by local triangle filtering of the seismic trace. With the application to real seismic data, it's shown that anti-aliased technique based on triangle filter can effectively remove operator aliasing compared with a conventional aperture-weighted approach.

针对东濮桥口南-徐集地区三维地震资料的特点及本区块的地质要求,制定处理流程,应用能量均衡、面元均化、三维道内插、三维DMO叠加及三维一步法偏移等技术方法,研究解决因为不同年代、不同方法、不同参数所采集的地震数据在连片处理时存在的问题,精细处理三维连片资料,满足构造解释精度的要求,对进一步落实该区构造和增储上产具有重要的作用.