SEDIMENTARY CHARACTERISTICS AND GEOLOGICAL SIGNIFICANCE OF SHALLOW SEA GRAVITY FLOW DEPOSITS IN THE GAS FIELD D, YINGGEHAI BASIN

Shallow sea gravity flow deposits are well developed in the Gas Field D of the Yinggehai Basin. So far the composition and characteristics of the sedimentary microfacies of the shallow sea gravity flow deposits have remained controversial. In this study, we summarized the characteristics of the lithofacies, logging facies and seismic facies of the field. A schematic classification of shallow-gravity flow microfacies suitable for the Gas Field D is established upon the known classifications of marine fan depositional systems both domestic and abroad in addition to the geological background of the target area. Sedimentary microfacies of erosional channel, channel side, distributary channel and depositional lobe are identified. Based on the above researches, this paper proposed an identification plate for shallow sea gravity flow deposits. According to the sedimentation model of the shallow submarine fan, the spatial distribution pattern of microfacies of the Gas Field D is confirmed.