伪声波曲线构建方法在尼日尔三角洲地区的应用研究

Application of Pseudo-acoustic Curve Method in the Niger Delta Region

岩性油气藏勘探开发的关键是地震储层预测,声波测井曲线又是地震储层预测不可缺少的基础资料,但由于种种原因很多地区得不到较好的声波测井曲线,这就需要构建伪声波曲线。构建伪声波曲线是根据能够反映储层特征的非声波储层地球物理测井信息构建的具有声波量纲的新曲线。声波曲线在本质上是一条速度曲线,它包含两个分量:①高频分量,反映井旁不同岩层的层速度;②低频分量,反映地层速度随深度加深而增大。在构建伪声波曲线时,则选用与声波具有良好相关性的测井曲线拟合高频速度分量,利用VSP速度拟合低频速度分量,最后将二者有机结合,就可得到所需的伪声波曲线。

Seismic reservoir prediction was the key for lithological reservoir exploration and development,and the curve of acoustic logging was also the indispensable basic information for the seismic reservoir prediction.But the better curve of acoustic logging was difficult to be obtained because of some reasons,so it was necessary to establish a quasi-acoustic curve.The quasi-acoustic curve is based on the new curve with acoustic dimensionless,which is established by non-acoustic reservoir geophysical logging information that could reflect reservoir characteristics.Acoustic logging curve is a velocity curve in essence,it includes two components : the first is high-frequency component,which reflects horizon velocity in different formations;the second is low-frequency component,which reflects that formation velocity enhances with depth.When building the acoustic logging,logging curves that are related with acoustic wave to fit high-frequency velocity components are selected,and VSP speed is used to fit low-frequency component,finally the two curves are integrated organically,it can obtain the quasi-acoustic curve that it is needed.