Study On High-resolution Sequence Stratigraphy And Sedimentary Microfacies Of ? Formation Of Du 84 Block In Liaohe Oilfield

Du 84,Liaohe Oilfield is located in the middle part of the slope belt in western Liaohe Depression.This block presents a l ong-strip shape with monoclinic structure tipping to east.By analyzing the sedim entary micro facies under th e control of high resolution sequence stratigraphy framework,this paper determined the characteristics of the distribution of stratigraphic sequences a nd the evolution of sedi mentary facies,and this has provides a fine exploration geological basis for next study.Based on the high resolution sequence stra tigraphy this paper has identified the sequence boundaries.Firstly,we analysed the characters of single well's layer,and then on the basis of single w ell's analysis we se lect 9 key profiles in the region.Under the control of the backbone profiles,we confirmed the stratigraphic division and correlation of all the 1735 wells in the study area and eventually established the high resolution sequence stratigraphic fra mework.The Xing I form ation in the s tudy area can be divided into 1 long-term depositional cycl e,2 mid-term depositional cycles and 4 short-term depositional cycles.The stratigraphic thicknessin in sou th is thinn er than north,and the provenance of the study area is northeast direction,along the direction stratigraphic thickness is gr adually thinned,while in the ver tical direction the stratigraphic thicknessin in middle is thicker than beside.This paper has analyzed the petrograghic characteristics through the characteristic,degree of ripeness,mudstone colour,sedimentary structure and other aspects,then build lithofacies template,and establish types of sedimentary microfacies.Secondly,by analyzing the characteristic of logs we confirmed the responding electrofacies templates.Finally,we concluded that the Xing I formation is developed fan delta front,and there are six sedimentary microfacies types including upper-water distributary channel,underwater distributary channel,interdistrbutary,mouth bar,sheet sand and shore-shallow lake.