【摘要】 随着地质勘探工作的不断深入,对构造图的精度要求也越来越高.因此,对速度场建立和变速构造成图方法也提出了更高的要求.中国东部大港探区在时深转换及构造成图中所用的传统方法是利用统一的华北速度公式来进行的,由于工区内钻遇深层古生界地层的井较少,且分布很不均匀,所以利用华北地区的井资料综合出的统一的华北速度公式对整个华北地区进行时深转换及构造成图存在一定的误差,特别是在复杂构造地区,误差更大,已不能满足实际生产的需要.本文在对大港探区歧南斜坡区内每一口井都进行精细的层位标定基础上,分析了传统方法中影响时深转换和成图精度的主要因素,指出了传统方法中造成误差较大、准确性较低的原因.采用处理资料的叠加速度、测井速度和地震地质标定速度相结合的技术,在三维空间分析该区速度变化,编制平均速度平面图、立体显示图等,实现空间变速成图.有效地提高了复杂地区速度场和构造图的精度,在实际工作中取得了较好的效果,具有良好的推广应用前景.更多还原

【Abstract】 With the continuous deepening of the geological exploration,the accuracy requirement of structural diagram is also more and more high,therefore,the establishment of velocity field and variable structure mapping method also are put forward higher request.The conventional method in timedepth conversion and structural mapping is using a unified formula based on the velocity of North China in Dagang exploration area in the east of China.Due to the deep Paleozoic strata were drilled in just several wells with uneven regional distribution,therefore,there is certain error in time-depth conversion and structure mapping especially in the complex structure areas when using the unified velocity formula of North China which is comprehensively obtained by the well data,and this already can ’ t satisfy the need of actual production.This paper studies the main factors that influence the precision of mapping and conventional method of time-depth conversion.It points the reasons leading to great errors and lower precision.Based on fine horizon calibration in each well in Qinan slope area of Dagang exploration area,during analysis,the time-depth relation curves of the wells are basically the same with the velocity of North China in the Neogene while the time-depth curves of the wells are apparently inconsistent with the velocity of North China in the Paleogene,Mesozoic and Paleozoic.In order to improve the precision of structural map,starting from solving the existed problems of the conventional method,a corresponding method to establish velocity field and variable velocity mapping is proposed,which uses processed stack velocity combining with logging and seismic calibration technique.The research on the change of the velocity in 3D space in this area makes up average velocity plan graph,3D display map and spatial variable velocity structure map.The application shows that this method can improve the precision of building velocity field and establishing structural map in the complex structure areas in the Dagang exploration area.This method achieves a good result in practice and shows good application prospect.更多还原