山前高陡构造区地震成图方法研究

A study of seismic mapping in frontlands of hills with steeply dipping structures

塔里木石油勘探开发指挥部勘探开发研究院计算中心,库尔勒841002

Computer Center of E&P Academy, Tarim E&P Headquarters for Petroleum, P.O box 123, City of Kuerle, Xinjiang 841002

库车山前高陡构造区因受地表结构复杂、地下地层倾角大、地层速度横向变化大等因素的影响,常规的地震偏移手段很难使地层准确归位,常规的地震成图方法很难使圈闭准确定位,勘探现实迫使我们必须寻找新的更加适合本区特点的成图方法以解决圈闭的准确定位问题。我们对影响山前高陡构造区地震成图精度主控因素进行了仔细的理论分析,指出了山区常规地震成图方法的不足,提出了合成谱、法向校正、变速图偏等新技术的技术流程,解决了山前高陡构造区准确的地震成图问题。

The fact that layers cannot be migrated properly using conventional seismic migration methods and traps cannot be delineated using conventional seismic mapping methods due to complexity in surface structures, steep dipping of layers, and lateral variations in velocity in frontlands of hills at Kuche area forces one to seek new and feasible mapping methods to solve the problem of proper delineation. After a detailed theoretical analysis about the main factors which affect the precision of seismic mapping in the steep dipping areas of the frontlands, we presents a new workflow in a creative way which makes precisely seismic mapping possible in the steep dipping areas. The new workflow consists of synthetic spectrum, correction in normal direction, velocity variant map migration, etc. and makes proper seismic mapping possible.