叠前地震裂缝检测在塔里木盆地玉北1井区的应用

The Application of Carbonate Pre-stack Seismic Fracture Prediction to YuBei 1 3D Area

塔里木盆地麦盖提斜坡玉北1井区奥陶系碳酸盐岩储集层埋藏深(超过6 000 m),非均质性强,纵横向变化快,预测难度大。利用玉北1井区钻井开展叠前正演模型研究及叠前方位各向异性裂缝检测研究,经过提取叠前振幅、相对波阻抗和频率衰减梯度等属性与钻井储集层标定对比,优选出对裂缝方位各向异性敏感的频率衰减梯度属性数据体进行裂缝密度和方位预测,预测结果表明玉北1井区目的层裂缝发育带在区域有一定的条带性,裂缝发育程度与区内北东向主干断裂带密切相关。通过叠前地震裂缝各向异性检测技术,提高了玉北1井地区裂缝型储集层预测的准确性,为该区下步勘探部署提供了指导依据。

Ordovician carbonate reservoirs in well Yubei 1 of Maigaiti slope in Tarim basin are buried deep(more than 6 000 m), with strong heterogeneity, rapid vertical and horizontal changes, and difficult to predict. The researches on pre-stack forward modeling and pre-stack azimuth anisotropic fracture detection are carried out by drilling in well Yubei 1. Fracture spatial orientation and density prediction are carried out, and fracture sensitive parameters are optimized. By comparing pre-stack amplitude, relative wave impedance and frequency attenuation gradient with drilling reservoir calibration, frequency attenuation gradient attributes sensitive to fracture azimuth anisotropy are selected. According to the prediction of fracture density and orientation, the prediction results show that the fracture development zone of the target formation in well Yubei 1 has certain zonality in the region, and the degree of fracture development is closely related to the NE-trending main fault zone in the area. Through pre-stack seismic fracture anisotropy detection technology, the accuracy of fractured reservoir prediction in well Yubei 1 is improved, which provides guidance for the next explorationin this area.