斜井三维VSP观测系统设计

Research on 3-D VSP geometry design for deviated well.

三维VSP资料具有高分辨率和高信噪比的特点,十分有利于井旁构造成像和油藏描述。由于海上三维VSP勘探大都在斜井中进行。因此,针对斜井的观测系统设计是否合理至关重要。在斜井三维VSP观测系统设计中,需要解决的主要问题有:①炮点分布中心位置的确定;②炮点缺失对覆盖范围和覆盖次数的影响;③多井炮点和多井检波点的布置等。通过模拟计算分析,对上述问题进行了探讨,得到了一些有益的认识。根据研究结果,制定了某实际斜井的三维VSP观测系统设计方案。

3-D VSP data has a high resolution and a high S/N ratio, which is quite helpful for the borehole-side structure imaging and reservoir description.Most of the marine 3-D VSP exploration is operated in deviated wells.So,reasonable 3-D VSP geometry de- sign for deviated wells is extremely important.In such a design, the main problems to be solved are:1) the definition of the center position for shots spread,2) the effect of shots missing on coverage area and fold,and 3) the arrangement of shots and receivers for multi-wells.Through simulation and analysis,the above problems were discussed;some beneficial conclusions were drawn.Accord- ing to the research result,the 3-D VSP geometry design scheme for one actual deviated well has been made.