碳酸盐岩高速层下伏构造的作图方法及效果

Mepping Methods and Effects for Studing Structure under the High Velocity Carbonate Formation

本文根据珠江口盆地东沙隆起区碳酸盐岩高速层厚度变化的影响,引起下伏构造层在时间剖面上的畸变特点,提出用速度替代法,平面变速时深转换法和射线深度偏移等三种方法校正灰岩高速层和作构造图。并以116-1油田为例说明三种方法的应用及效果。

On Dongsha massif of the Pearl River Mouth basin, the varied thickness of high velocity carbonate formation causes the distortion of underlying structure oa the two-way time sections and makes mapping the potential objective underneath the carbonate a problem which needs to be solved. Three methods used for mapping underlying structure in accordance with the specific reality are presented here, firstly the velocity replacement method, seondly the plane-variant velocity time-depth conversion, and lastly the ray tracing depth migration. A more accurate structure map has been obtained by using these three methods on H 6-1 structure-a perfect draping anticline exhibited in stead of the original nose on the time map. This has been confirmed by drilling and tested with good quality and high production of oil from sandstone reservoir underlying the carbonate, which should be attributable at least partially to the new mapping technique.