Study On Sedimentary Facies And Reservior Characteristics Of First Member Of Badaowan Formation In Chunhui Oilfield

Chunhui Oilfield was located in Hashan area in the northern margin of Junggar Basin, of which the Jurassic Badaowan Formation is the main oil-bearing strata, and the sedimentary facies and favorable reservior distribution regularity constrained the further exploration and development of Chunhui Oilfield. Therefore, This paper according to the problems existed in the study area, comprehensively utilizes geological, logging, analysis and production data, studying the sedimentary facies and reservoir characteristics. The following results were achieved:(1) The sedimentary stratigraphic framework of Firsth Member of Badaowan Formation is established, which divided into three sand groups: J1b11, J1b12 and J1b13. Illuminated the character of the distribution of roomage of the stratums.(2) Assured that Firsth Member of Badaowan Formation is middle fan braided river deposition.Combined with petrologic characteristics, further divided into 4 lithofacies, including the middle fan braided river conglomerate facies, the middle fan braided river glutenite facies, the middle fan braided river sandstone facies and the middle fan braided river interchannel mudstone facies. Illuminated the character of the distribution of roomage of the sedimentary facies. Established the sedimentary facies model of the study area.(3) Point out that the main rock types are granule conglomerate, glutenite and mid-fine sandstones. The compositional maturity and textural maturity of the reservior’s detrital component are low. The main diagenesis are compaction and cementation, replacement and dissolution are not obvious.(4) The reservoir heterogeneity are fine depicted, and the quantitative characterization of reservoir heterogeneity has been achieved. Reveal that different sedimentary facies and inhomogeneity of the diagenesis affect the reservoir heterogeneity. Point out that from sandstone facies to conglomerate facies to glutenite facies, the reservoir heterogeneity intensified. And areas with better properties have lower reservoir heterogeneity, areas with worse properties have higher reservoir heterogeneity(5) The method of comprehensive multi-parameters to divide favorable blocks is proposed. The reservior is divided into four categories,they are the most favorable block, favorable block, less favorable block and general block. From south to north, the favorable block turn to the general block. The reservior attribute of sandstone is more favourable than the reservior attribute of conglomerate and glutenite, which is the key area of further exploration and exploitation.