| The Ledong gas field group is located near the slope break zone of the Yinggehai Basin, and the gas field has
entered the middle and late stages of development, and it is of great significance to clarify the distribution of residual gas
for tapping the remaining potential of the gas field. It is important to conduct research on sedimentary facies types,
sedimentary models, sand body stacking relationships, and configurations based on rock facies characterization, grain size
analysis, logging facies identification, and seismic facies characterization of the 1st member of Yinggehai Formation.Two
types of sedimentary facies are identified in the research area, including littoral-shallow marine, and submarine fan.
Among them, the littoral-shallow marine subfacies can be further subdivided into three types of sedimentary microfacies:
shoreface bar, shoreface beach, and shelf mud.Three types of sedimentary models have been established: progradational
shallow marine beach-bar composite model on the gentle shelf slope; slump-reworked bar-filling depositional model at
the slope margin; shallow marine gravity-flow slump fan model below the slope break.Three types of sand body stacking
relationships have been identified: progradational stacked sand bodies developed above the slope break zone exhibit good
connectivity; laterally contacted stacked sand bodies (formed by slump-reworked bar sands) near the slope break show
moderate connectivity;vertically isolated submarine fan sands deposited below the slope break display poor connectivity.
The slump-reworked bar sand bodies near the slope break zone and the submarine fan-derived sand bodies below the
slope break are identified as the most promising potential targets for future gas field development. |
