加蓬盐下复杂构造区井控高精度变速成图的方法研究

A study of the method of well controlled high precision variable velocity mapping in the subsalt complex structure area of Gabon

随着油气田开发的不断深入,对地震资料解释和构造成图精度的要求越来越高。尤其是在地表复杂、地下结构复杂、陡倾角地层的地区,必须建立高精度速度场,采用变速成图来获得高精度构造图,才能精细落实构造。然而在复杂构造区,速度在纵向和横向上往往变化都很大,采用常规的速度模型,很难得到精确的构造模型。在研究目前针对复杂地区常用的速度建模技术的基础上,提出了充分利用统一校正后的钻井速度、地震速度谱等资料,再结合层位控制法来建立地震测井互相约束的三维速度模型,最后通过时深转换,绘制出构造图的技术方法。该技术在加蓬陆上开发区盐下构造的研究中取得了很好的效果。

With the deepening of oil and gas field development,seismic data interpretation and structural mapping accuracy requirements are also increasing.Especially in complex surface,underground complex and steep dip formation regions,high-precision velocity field must be established with variable velocity mapping to obtain a fine structure diagram and fine implementation of construction.However,in the complex structure area,it is difficult to get an accurate structural model with the conventional velocity models,because speed change is very big also in the vertical and horizontal direction.Based on the study of currently used velocity modeling techniques for complex area,the authors put forward the technical method about seismic and logging constrained 3D velocity model that takes full advantage of unified corrected wells velocity,seismic velocity spectrum and other information and,combined with layers control action,finally uses the time depth conversion to realize the structural mapping.Research on the technology for the construction of onshore Gabon Zone salt has achieved good results.