Research On Sequence Stratigraphy And Sedimentary Facies Of Sha2-Sha1 Formation In Huan-Shuang Area In Liaohe Oil Field

This paper mainly studies about identifying the litho stratigraphic trap by using the sequence stratigraphy theory and methods.In this paper, the author improves the"Single factor analysis and multifactor comprehensive mapping method".The author studies and analysises the different school of the theory and methods of sequence stratigraphy . The CROSS sequence stratigraphy can correctly do it. This paper studies the Liaohe west depression Sha 2 to Sha 1 formation sequence stratigraphy characteristics under the guide of Cross high-resolution sequence stratigraphic theory through the combination of geological datas, seismic datas, well logging datas, drilling cores, other related analyzed datas and experimental techniques. And the paper establishes the sequence stratigraphy framework by dividing the formation of interest into 1 long-period cycles (third-order sequences) and 2 middle-period cycles(fourth-order sequences). The author presentates the"proporti- onality of single factor mapping method". This is a method of quantification study of sedimentary microfacies upon proportionality of distribution of grain size.This method makes the sedimentary facies horizontal plan in the process not only uses the application tradition sandstone isopach map and sandstone percentage chart and so on, but introduces the each single factor relastive vlue isogram of coarse sand/ sand, the silty-fine sand/sand and the shaly sand / sand to study the deposit microfacies of the fan delta sands body in this arear. This method enhances the researchful definition of sedimentology facies.The author points out that in fan delta front subfacies,the relative value of submarine distributary channel coarse sand/ sand is above 60%, but generally speaking, the relative value silty-fine sand/sand and the shaly sand / sand is lower than 20% ; In the fan delta front submarine interdistributary area, the relative value of Coarse sand/ sand is 40-60%, the silty-fine sand/sand and the shaly sand / sand value all is lower than 20% in general; But in abandoned channel region, the coarse sand/ sand relative magnitude is lower than 40%, the silty-fine sand/sand relative value is higher than 40%, the shaly sand / sand value all to be lower than 20% generally; The coarse sand/ sand relative value which in mouth bar is in the scope of 0-40% , the silty-fine sand/sand relative value is higher than 40%, the shaly sand / sand value is lower than 20%; The coarse sand/ sand relative value which in the sill-like sand is 0-40%, the silty-fine sand/sand relative value is higher than 40%, the shaly sand / sand value is higher than 20%.On the basis of the analysis of Sequence Stratigraphy and Facies ,the author indicates that the Reservoir sands in shuang huan are mainly Distributary river sand, the river diversion of sand, sand and mouth bar seats with sand sand. According to the Sequence datum's diagram in every period,the thickness map of sandstone, and other informations,the author points that,the south of shuangshen3 block distributary channel deposit and mouth bar sand body, the huannan5 mouth bar sand body in the C1 time and the north of shuang210 block fluxoturbidite and so on product body, west of huan101 submarine distributary channel in C2 time are the favorable places for prospecting of litho stratigraphic trap .The development of oil field and the deployment of well position can be actually studied in those areas.