辽河油田大民屯凹陷地震资料的成像技术

Imaging technique of seismic data in Damingtun sag of Liaohe Oilfield

大民屯凹陷是辽河断陷北端的一个次级构造单元,该区地表条件及地质构造复杂,凹陷东、西两侧发育高角度逆断层,使得地震资料处理工作面临两个亟待解决的地质问题:一是下第三系沙三段、沙四段碎屑岩储层的详细评价和横向预测;二是陡坡带局部构造的准确落实和成因机制研究。本文以近年精细采集的480km2三维资料为背景,针对构造主体部位的深层和东、西两个复杂构造陡坡带资料,开发及应用炮域波动方程叠前深度偏移成像技术,形成了一套针对大民屯凹陷资料特点的成像技术和流程。实际资料处理表明,成像效果明显改善,发现了7个有利圈闭,预测有利含油面积32.7km2。

Damingtun sag is a secondary structural unit in north part of Liaohe fault depression,where the surface condition and geologic structure are complex and reversed faults developed on east and west sides of depression that made seismic data processing work face with two urgently solved geologic issues: the one was the detail appreciation and lateral prediction of Paleogene Es3 and Es4 clastic reservoir; the other was accurate definition of local structure in steep slope zone and study of genetic mechanism. Taking 480 km2 of 3-D data finely acquired in recent years as background and data in deep formation of main structural parts and in east and west complex steep structural zone as objects, the paper developed and applied prestack depth migration of wave equation on shot domain and formed a set of imaging techniques and flow considering the feature of data in Damingtun sag. It was shown by practical data processing that imaging effects were significantly improved, 7 prospective traps were discovered and prospective oil-bearing area of 32. 7km2.