基于分频叠前偏移数据体的碳酸盐岩缝洞精细刻画

经过数十年的勘探开发, 塔里木盆地塔北地区奥陶系碳酸盐岩缝洞型油藏勘探开发已由早期的大尺度缝洞向小尺度缝洞迈进。如何精细刻画缝洞的轮廓、缝洞内幕结构以及识别小尺度缝洞成为现阶段油田增储上产的关键。常规叠前时间偏移、深度偏移以及逆时偏移地震数据体的纵、横向分辨率难以满足上述需求。基于高频段分频叠前时间偏移成像数据体, 经过振幅属性与地震反射强度交流分量属性的对比, 优选地震反射强度交流分量属性数据体, 应用三维可视化技术, 有效刻画了不同尺度缝洞的空间展布。将该技术应用在塔河油田某三维工区80km²实际资料的解释, 结果表明, 与基于常规叠前时间偏移数据体的缝洞识别结果相比, 此项技术不仅可以提升大尺度缝洞轮廓的刻画精度, 还可以判别缝洞组合体的内幕结构。更重要的是, 该技术大幅度提升了小尺度缝洞的识别精度。该研究成果对塔北地区今后增储上产和井位部署具有广泛的应用意义。

In the past few decades of exploration and development in the Tarim Basin, the development of Ordovician carbonate fracture-cavity reservoirs in the northern region of the Tarim has moved from the early large-scale fracture-cavity reservoirs to small-scale reservoirs. Fracture-cavity reservoir contour description, internal structure prediction. and small-scale cave detection have become the key points for reserve and production growth. Based on high frequency-division pre-stack time migration data volume, we used the perigram, root mean square amplitude attribute, and 3D visualization to finely characterize the spatial distribution of different scale fractures and caves. This technology has been widely applied in the Tahe Oilfield with a work area of 80km². Compared with the identification results of fracture-cavity based on conventional pre-stack time migration data volume, this technology can improve the accuracy of fracture-cavity reservoir contour description and also distinguish the internal structure of fracture-cavity combinations. More importantly, it can considerably improve the precision with which small-scale fracture-cavity reservoirs are identified. The research results reported here have broad applicability and importance regarding future hydrocarbon development and production, as well deployment in the northern region of the Tarim Basin.