高精度三维地震采集技术攻关及在松辽盆地南部应用效果

The 3D High-precision Seismic Acquisition Technology and Its Application Effect in the South of Songliao Basin

吉林探区将面临"低幅度、小断层、薄砂层"等复杂油气藏勘探领域。为了利用地震资料来分辨垂直断距5m以上的断点,查清延伸长度0.5km以上的断层;落实幅度大于5m、面积大于0.3km2的小构造和识别岩性圈闭,吉林油田在松辽盆地南部的乾西北地区开展了高精度三维地震采集技术攻关。通过野外基本参数试验和观测系统属性分析,初步形成了一套较为适用的三维地震采集技术。勘探实践已经证明:采用砖墙式观测系统(12线×140道×18炮,覆盖次数为6×10次)三维地震采集技术在松辽盆地南部油气勘探中起到了关键性作用。经高精度采集攻关和精细处理解释而得到的乾西北地区三维地震成果,不仅有助于快速刻画和认识地下油藏三维地质特征,而且为勘探提供了准确的钻探目标,有效地解决松辽盆地现阶段存在的微幅度构造、小断块圈闭和薄层岩性问题,提高了探井成功率,带来了可观的经济效益。

Now we are facing some complicated reservoir, such as low amplitude, small fault and thin sandstone layer in Jinlin exploration field. So 3D high-precision seismic acquisition is studied and developed in Qianxi of the south of Songliao basin for distinguishing flaw with vertical fault distance greater than 5m, fault with more than 0.5km of extending length, small structures with 0.5m of structural amplitude and more than 0.3km2 of area, and identifying lithological traps. Seismic acquisition has been improved greatly and a suitable 3D seismic acquisition is formed incipiently through basic field parameter trial and attribute analysis of observation system. Exploring practice shows that it has played a key role during exploration in the south of Songliao basin by brick-wall observation system (121ines× 140traces× 18shots). In Qianxi area, 3D seismic data from high-precision acquisition studying and detailed processing and interpretation not only help to obtain quick depicting and recognizing 3D reservoir geological characters but also offer accurate drilling targets for exploration. Progress at seismic acquisition has effectively accounted for solving the problems of tiny-range structure, little flaw trap and lamina, and improved the rate of successful exploration well and promoted considerable economic benefit.