Sedimentary Microfacies: A Case Tudy Of K₁yc₄ Conglomerate In Xingcheng Region, North Songliao Basin

Xingcheng gas field located in the Xingcheng nose structure of south east fault subsidence of Song liao northern deep structure unit , Yingcheng four-conglomerate reservoir is one of the primary reservoir of Xingcheng gas field. To accumulate the exploratory development step of Xujiaweizi deep nature gas and to meetcontent the needed of development program of Xingcheng gas field ,we developed the elementary geologic research of conglomerate reservoir.First of all ,this paper studies the Ying four- faultage by means of fine respecting and description of rock core , and a great quantity of mineralogy identify of petrographic thin section, and calculation analyse of the picture of cast thine slice , and observation of scanning scanning electron microscope,etc. Generalize the total feature of the Ying four-faultage is : the thick gray green partical support the massive bedding (volcan) pebblestone. Target the difficulty of identify and divide of thick conglomerate reservoir intrastratal contributing factor ,we develop the high definition sequence stratigraphy which united by fine dissection of step rate core well ,field exposure,drill core ,well logging and earthquake seismology, we divided the Ying four-faultage into two middle period succession and ten short-term succession,and establish of the stratic dimensional pattern of faultage. Inquirement of the contributing factor of Ying four- faultage of this region is braid river delta transitional"shallow rudaceous braid river fan delta facies"based on the deposition feature and united it sedimentary structure feature ,and classified it as three deposit sub-phase .By means of the analysis of single well phase and compared the cut plane of portrait and horizontal deposition microfacies , analysed the feature of deposition microfacies and plain distribution, and generalized the precipitation facie pattern of the Xingcheng area. The short period stratic plane precipitation microfacie of Yingcheng formation four- fragment disclosure it's inside feature of the heavy layer conglomerate ,indicate the influence of the Ying four-faultage deposition microfacies for the physical property of the reservoir, offer an definite foundation for the forecast of the Yingcheng four-conglomerate reservoir.