塔里木盆地地震反射异常体及其地质属性初探

Pilot study on seismic anomaly body and its geological characteristics in Tarim basin.

塔里木盆地在奥陶系、石炭系和二叠系等不同层系中存在很多地震异常体，这些异常体多数因沉积作用、构造作用而形成，部分已被钻井证实为特殊异常体，大部分异常体还未进行钻探。依据地震反射特征和内部反射结构识别异常体地质属性，将其归纳为９类，即下切状、楔状、丘状斜交前积、蘑菇状、树枝状、枕状、丘状、下凹状和透镜状异常体。通过沉积环境、速度分析以及合成声波处理研究后认为，这些异常体多数为陆相古河道砂体或海相生物礁、滩的反映，储集条件优越，如果有充足的油气源，无疑是今后勘探的有利目标。在钻探这类圈闭和目标之前，必须紧密结合地球物理、地质、测井分析，进行综合评价，才能减少风险，取得较理想的钻探效果。图１参１（李建国搞）

In Tarim basin there are many seismic anomaly bodies in the Ordovician, Carboniferous and Permian which are mostly caused by sedimentary and structure process. Some of them have been discovered and proved by drilling well and most of them are not. Based on the seismic reflection characteristics and inside reflection structure these seismic anomaly bodies could be classified into 9 kinds as downward cut, wedge, mound diagonal forest, mushroom, arborization, pillow, dome, down concave and lenticular bodies. Depending on the study of sedimentary environment, seismic velocity analysis and synthetic sonic logs proceeding, most of them are confirmed as nonmarine paleo-channel bar or marine reef and organic bank with good reservoir condition. They will become exploration targets if nearby there have sufficient hydrocarbon source. To a favorable seismic anomaly body research work of geophysics, geology and logging must be united and the comprehensive study should go deeply to reduce the exploration risk and get a good result.