The Chang-7Geologic Model Building Of An-83Wellblock In Hu Jianshan Oilfield

The exploitation of chang-7reservoir in Hu Jianshan oilfield has achieved many new accomplishments, which open out a promising trend. It is important to explore the high-efficiency technique and policy in chang-7reservoir, because it might be a new pre-production and exploitation oil layer. An-83wellblock, which is the main trial part, is in the middle of HuJianshan oilfield.Based on information collection, field core observation combined with a variety of core analysis and testing methods to study the stratigraphy, structure, sedimentary, reservoir and other basic geological characteristics of Chang-7reservoir in An-83wellblock, the study comprehensively apply multi-disciplinary theories and methods. The geological model for three-dimensional visualization of Chang-7reservoir in An-83wellblock, which established by the PETREL software, provides geological model and the theoretical basis for the probe of exploitation technique and policy.The study shows that:1) Chang-7reservoir in An-83wellblock is a general slowing western-leaning monoclinal structure, anomalous nose structures are developed in the middle of the An-83wellblock;2) delta front facies sedimentary system is developed, the four micro-facies are underwater distributary channel, mouth bar, distributary bay and front sand sheet;3) Chang-7reservoir consists of gray and gray-brown feldspar-porphyry sandstone, with low mineralogic maturity, moderate textural maturity, low porosity and permeability and strongly water wetting reservoir;4) Based on the research of four-property relations, the reservoir properties interpretation models were set up,Φ=0.2433△t-0.0673GR-32.4362; lg(K)=0.0010△t-0.0145GR-0.0079SP;the lower limit of porosity is identified as5.2%, the lower limit of permeability is0.035×10-3μm2.5) Macroscopic heterogeneity of Chang7reservoir in An83block is medium weak, the prominent feature is macroscopic heterogeneity in river edge is strong, the reservoir heterogeneity is controlled by sedimentary facies, so it is necessary to combine the cognition of reservoir geology with the3D geological model.On the basic geological characteristics of Chang-7reservoir in An-83wellblock, three-dimensional geological model of Chang7reservoir is established using the PETREL software, including the well model, structural model, facies model and properties model, such as porosity model, permeability model, oil saturation model, net/gross ratio model etc. The model highly display the sand body of the reservoir and characteristics of the properties, at the same time provide the data volume for subsequent simulation and lay the foundation for further exploitation.