Ultra‐thin, lacustrine sandstones imaged on stratal slices in the Cretaceous Qijia Depression, Songliao Basin, China

Abstract

Exploration and development of ultra‐thin (0.5–3 m) sandstone reservoirs are one of the important strategies for future reserve growth in Songliao Basin, China. This study presents an exceptional example in which direct imaging of ultra‐thin depositional systems on stratal slices and a quantitative estimation of thickness by using an amplitude‐thickness tuning curve are achieved. Channel forms in highly linear and networked géomorphologic patterns on a stratal slice are verified by core and wireline logs to be distributary channel‐fill sandstones in a lacustrine, shallow‐water deltaic system. Seismic amplitude and sandstone thickness measured at well sites demonstrate a linear relationship in a thickness range of zero to 10 m. The seismic detectable limit achieved in this case is about 1 m, or λ/64.