库车坳陷山地复杂构造速度场研究及其应用效果

Velocity Field Research of Complex Structures in Kuqa Depression and Its Application

在库车坳陷盐下构造油气勘探中,因受上覆地层构造形态和层速度结构的影响,在时间剖面里发生畸变而形成假构造,与地下实际构造形态存在很大差异。变速成图过程包括构造建模和速度场建立这两部分,而速度场精度成为影响圈闭落实精度"瓶颈"之一。采用多种有关的速度信息(测井、地震、沉积相、构造、压实及应力)建立的速度场,具有高的精度,更能反映地层速度的纵横向变化。为变速成图提供准确的速度模型,有效地校正时间剖面上的构造畸变现象,从而提高构造圈闭落实精度。

During the oil and gas exploration in subsalt structures of Kuqa Depression,the time section occurs distortion and forms pseudo-structure,because of the overlying strata structural morphology and velocity structure.The pseudo-structure differs a lot from underground actual structure.The variable velocity mapping includes the establishment of structure modeling and velocity field,but the velocity field accuracy affects the accuracy of trap identification.A velocity field,containing log information,seismic information,sedimentary facies information,structure information and stress information,etc.,could better reflect the longitudinal and lateral variation of formation velocity,with its high accuracy.It offers an accurate velocity model for variable velocity mapping,corrects distortion of the time section effectively,and thus improves the accuracy of trap identification.