王集地区复杂断裂构造带高精度三维地震成像研究

王集地区目的层埋藏浅,北东向与北西向两组断裂相互交切,小断块发育,地层横向速度变化大,小断层难以有效识别。针对上述特点,采用层析反演静校正和拉伸畸变切除技术提高了浅层信号的信噪比,采用叠前时间偏移技术提高复杂断裂带断层的成像精度。在速度模型建立过程中,充分考虑了构造特点及速度变化规律,利用水平与垂直速度切片约束,求取更为精确的速度场。在高精度三维地震成像研究中,对叠前偏移中的偏移孔径、偏移速度和偏移角度等关键参数的选取开展了深入细致的研究。根据倾角确定孔径,通过迭代确定最佳偏移速度,通过综合解释研究,在泌阳凹陷王集地区核三下段发现了一批新的断块圈闭,经钻探在新层系核三下段首次获得工业油流,扩大了该区勘探领域。

High-precision 3D seismic imaging of complex fractured structural belt in Wangji area

In WangJi area,the target intervals are shallowly buried,and the two groups of fractures in northeast and northwest direction are cross-cutting.In addition,small faulted blocks are developed and the velocity has large lateral variation,so the small faults are difficult to identify effectively.Aiming at the problems,we adopted tomography inversion statics and stretching distortion cut technology to increase the signal-to-noise ratio of shallow signals,and used pre-stack time migration technology to increase the imaging accuracy of complex faulted zone.During the velocity model building,we took full account of the structure characteristics and the law of velocity variation,under the constraint of horizontal and vertical velocity slices;more accurate velocity field was obtained.In the research of high-precision 3D seismic imaging,we focused on the selection of the key parameters of pre-stack migration,such as migration aperture,migration velocity and migration angle.We selected aperture by dip and choose best migration velocity by iteration.Through the integrated interpretation,a group of new traps in HeIII lower segment,industrial oil flow were obtained in HeIII of the new drilled formations for the first time,which broadened the exploration scale of the area.