The Donghe Sandstone is constituted of the Donghetang Formation from the Upper Devonian and the Bachu Formation from the Lower Carboniferous.A basin-wide tracing and correlation of the sandstone combined with a fine study of its sedimentary evolution is currently a major task for further oil and gas exploration in the basin.Guided by sequence stratigraphy theories

we analyzed in detail the sequence stratigraphy and sedimentary evolution of the sandstone based on a wealth of data

including drilling data

mud and wire logging data

cores and seismic data.Two types of sequence boundaries together with two second-order sequences and six third-order sequences (SQ1-SQ6) were recognized in the sandstone and a basin-wide sequence stratigraphy framework was also built.The result showed great influence of palaeogeomorphology upon the distribution of the sequences and an almost intact SQ4 to SQ6 in the whole basin.Within the sequence stratigraphy framework

there were five sedimentary facies

such as delta facies

longshore facies and etc..A study of plane sedimentary evolution of the sedimentary facies showed that during the deposition of SQ1 to SQ6

the deposition area of the sandstone had gradually enlarged

with favorable conditions for the development of potential lithologic traps in SQ4 sandbody of Shunnan area

in SQ5 sandbody of Shunxi area and in SQ6 sandbody of Shuntuo area.Further exploration shall be focus on these sandbodies.