社団法人 物理探査学会
第141回(2019年度秋季)学術講演会


PS速度検層をめぐる技術的課題(その4):ハイドロフォンアレイツールを用いたS波VSPと高分解能S波反射法断面との対比

講演要旨(和文)
ハイドロフォンアレイツールによって孔井内でダウンホールS波VSPを実施することが可能である.そのVSP解析結果を他の速度検層結果と比較検証してS波相であること確認するとともに,そのプロファイルを高分解能S波反射法探査断面と対比し,両者が整合的であることを示す.

講演要旨(英文)
Hydrophone array tool is quite practical for PS logging because the tool does not need to be coupled with the borehole wall during measurement. In addition, we can extract not only P-wave phase but also S-wave phase data under some specific conditions. The author has utilized the hydrophone array tool for PS logging sine 1992 in a total of 25 boreholes together with conventional downhole tools and the Suspension PS logging tool. S-wave VSP processing was applied to the data obtained by using the hydrophone array tool and correlated with high-resolution S-wave seismic reflection sections. As a result, the VSP profiles were basically concordant with seismic sections. The tool is useful not only to derive P- and S-wave velocity structure from first breaks but also to reconstruct PS VSP profiles using full-wave data.