石油・天然ガスの探鉱におけるシーケンス層序学の意義  [in Japanese] Significance of sequence stratigraphy in petroleum exploration  [in Japanese]

近年, 石油鉱業界や学界で注目を集めているシーケンス層序学は, 石油地質学的には, 成因によって定義し得る層序区分単位に基づき, 層相分布予測, 広域的地層対比および堆積盆地解析を行うことによって, 有望な探鉱対象地域の摘出を行うための手法である。石油探鉱におけるシーケンス層序学の最も重要なセールスポイントは, 地層の成因論に基づく (1) 堆積モデルの適用による堆積相分布の予測性向上, (2) 層序学的解析精度の向上, の2点に集約される。シーケンス層序学を応用した石油・天然ガスの探鉱は, 近年世界各地で活発に進められており, 成果を上げつつある。

Sequence stratigraphy, which has been attracting attention around the world recently, is regarded as a stratigraphic method from the petroleum geologists' point of view that may provide ideas of suitable areas for petroleum explorationon the basis of prediction of sedimentary facies distribution and high resolution global and regional stratigraphic correlations using stratigraphic units defined by their genesis. The most important points of advantage for sequence stratigraphy in petroleum exploration may be summarized as i) improvement for predictability of sedimentary facies distribution using depositional models, and ii) improvement of the resolution of stratigraphic analyses using a standard of global sea-level curve based on the genesis of strata. The concepts of sequence stratigraphy have been actively applied to petroleum exploration in the world during these past few years, and this has lead to relatively favorable results.