基于静校正模型的速度场基准面转换方法

本文从基准面静校正技术和CMP参考面的定义出发,对速度场从CMP参考面转换至统一基准面存在的问题进行了深入研究,获得了静校正模型中高速顶界面或中间参考面在时间域和深度域均具有确切定义的认识,提出并实现了从CMP参考面至高速顶界面或中间参考面的介质剥离,从高速顶界面或中间参考面至统一基准面的常速介质充填的速度场基准面转换方法,较好地解决了速度场从CMP参考面到统一基准面的转换问题,为充分利用地震速度信息建立时深转换速度场奠定了基础。该方法具备明确的物理意义,所获得的统一基准面速度具有较高的时深转换精度,在鄂尔多斯盆地东缘煤层气新探区取得了良好的应用效果。

An Intermediate Reference Datum Static Correction Technique and Its Applications

Static corrections using the conventional method are basically conducted in two steps, the weathering correction followed by the correction from the top of the sub-weathering to the unified datum. However, the conventional method fails to well deal with statics problems in case the top of the sub-weathering is sharply undulated and the lateral velocity of the sub-weathering varies significantly. This brings us to the introduction of a smooth intermediate reference datum （IRD） located under the top of the sub-weathering, which helps to further increase the accuracy of statics based on the weathering corrections, and ensures the imaging quality. Good results based on the IRD technique have been achieved in the complex areas in western China. This paper discusses the IRD functions, its application requirements, and selection of related parameters. Some typical sections for comparison are also given in this paper.

塔里木盆地顺托果勒南区块地震接收技术研究

塔里木盆地顺托果勒南大沙丘区单炮信噪比低、反射同相轴连续性差,造成主要目的层志留系、奥陶系内幕反射不清,地震采集资料难以满足落实圈闭的需要。为此,开展了地震采集接收技术攻关,研究出高速层顶界面的界定方法,分析和研究了地震信号吸收衰减与近地表速度之间的关系,并通过逐点设计组内高差和对组内高差实施可视化监控,使得地震资料品质得到较大幅度地提高。

黄土塬区模型约束折射静校正技术应用研究

鄂尔多斯盆地东缘黄土塬区地形起伏剧烈,低降速层厚度和速度横向变化大,表层结构复杂,折射波静校正表层模型建模困难,静校正问题突出.本文通过黄土塬区表层结构规律分析,提出了一种基于初至走时层析求取近地表速度、以等速度界面近似高速顶界面的表层模型约束建模方法;在基准面静校正概念的基础上,对比分析了基岩顶界面、层析速度收敛面等不同折射面解释方案对静校正量、标志层反射时间及平均速度的影响,结合实际钻井资料证实了在黄土塬区以基岩顶界面作为折射面能够获得正确的静校正量、标志层反射时间与平均速度.