三维连片叠前深度偏移技术在大港某油气田勘探中的应用

Application of 3D Linking Pre-stack Depth Migration Technique in Dagang Buried Hill Gas Reservoir

大港千米桥潜山目的层埋藏深,速度横向变化大,地下地质情况复杂。叠后、叠前时间偏移地震资料不能满足地质需求。为此,采用了提高潜山成像精度的最有效手段,三维连片叠前深度偏移处理技术对该区进行重新处理。文中介绍了叠前道集精细处理、建立初始深度—速度模型、模型的优化、偏移与校正等技术与实现过程。新处理的叠前深度偏移地震资料与旧资料对比,不仅成像精度高,而且得到的波动信息更加丰富。应用新资料重新评价千米桥潜山气藏,取得了一些新认识和显著的地质效果。

The objective interval of Qianmiqiao buried hill has buried deep,big lateral variation of velocity and the complex underground geological conditions.The post-stack and pre-stack time migration seismic data can not meet the geological demands.For this reason,the most effective method is adopted for re-treatment contiguous three-dimensional pre-stack depth migration processing technology in the area to improve imaging precision in Dagang buried hill.This paper introduced some technique and the realization processes such as fine treatment of pre-stack gathers,the establishment of the initial depth-velocity model,model optimization,model deviate and model correction,etc.By comparing with the old seismic data,the new seismic data of pre-stack depth migration get higher accuracy and more abundant wave information.We use the new seismic data to evaluate Qianmiqiao buried hill gas reservoir,and get some new understanding and significant geological effects.