斜井三维VSP观测系统设计

Research on 3-D VSP geometry design for deviated well

（1.中国科学院地质与地球物理研究所,北京100029；2.中国石油大学CNPC物探重点实验室,北京102249；3.中海石油（中国）有限公司北京研究中心,北京100027；4.中国石油化工股份有限公司勘探开发研究院,北京100083）

Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

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 design 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. According to the research result, the 3-D VSP geometry design scheme for one actual deviated well has been made.