叠前深度偏移技术在焉耆盆地宝南地区的应用

The application and investigation of 3-D prestack depth migration in Baonan area of Yanqi basin.

中国石油化工股份有限公司河南油田分公司石油勘探开发研究院, 河南南阳473132

Exploration & Development Institute, Henan Bureau of Petroleum Exploration, Nanyang 473132, China

焉耆盆地宝南地区构造复杂,以往处理的三维地震资料品质差、信噪比低,三维叠后时间偏移成像效果差, 断裂和圈闭的成像精度不高,空间位置不准确,为此进行了叠前深度偏移处理的研究。介绍了Kirchhoff积分法叠前深度偏移的基本原理和实现过程,分析了主要参数(去假频距离、偏移孔径、延拓步长等)对复杂构造成像效果的影响,给出了焉耆盆地宝南地区三维地震资料叠前深度偏移处理结果。对比分析了叠前深度偏移、叠后时间偏移和叠前时间偏移结果,分析表明,叠前深度偏移技术能较好地改善该区复杂构造的成像质量,提高资料的信噪比和分辨率。

The position of faults and traps is less reliable due to the poor quality , low S/N ratio of raw 3D seismic data and dissatisfactory image effect of poststack time migration. The study on methods of poststack depth migration is carried out. This paper introduces the basic theory and performing procedure of Kirchhoff migration, discusses the influence on image from main parameters. Analysis of the results suggest that poststack depth migration has more advantages in improving S/N ratio, resolution and image effect than poststack time migration and prestack time migration.