Log Evaluation On Low Permeability Reservoir Of The Member 3 Of Shahejie Formation In The Fifth District Of Bonan Oilfield

The Fifth District is situated southeast of Bonan Oil Field,the central oil-bearing series is the sixth and ninth sand group of the Es3.The Es3 has the following characteristics: deep buried depth, bad physical property and complex pore texture, so it is difficult for computing log reservoir parameters. Therefore, analyzing reservoir four characteristics (lithology, physical property, oil-bearing property, electronic property characteristics) and their correlations, founding suitable clay content and porosity, permeability, oil saturation parameters log interpretation model, determining effective thickness interpretation standard, Establishing practicable log interpretation methods in the reservoirs is significant for the Bonan oil filed to develop effectively.Firstly,through the investigation of reservoir basic geological characteristics of the study region, stratigraphic characteristics, Structural characteristics and sedimentary characteristics are studied. Stratigraphic characteristics are mostly interbedded of thin packsand,siltstone and thick mudstone. The sedimentary facies is mainly delta front and turbidite fan subfacies. Many reservoirs are mediμm porosity and mediμm-low permeability, and with the increase of buried depth reservoir physical property become worse. This thesis focus on analyzing core section analysis data, well log data and testing oil data, deeply studying rsservoir lithology, physical property, oil-bearing property and electronic characteristics, systematically analyzing reservoir four property correlations. On this basis, combined the actual situation of the district, the study region is layering to establish suitable clay content and porosity, permeability, oil saturation parameters log interpretation model. and make use of core section analysis data and testing oil data verifying interpretation model. And again, effective thickness interpretation standard is determined according to testing oil data. And log response characteristics of the interlayer in the reservoirs are also analyzed and deducted. In accordance with the total data of log interpretation parameters, spatial distributed characteristics of reservoir parameters are analyzed. Permeability heterogeneity parameters in layer are calculated, and overall, permeability heterogeneity intensity in layer is mediμm, partly strong. This paper discuss the variation features of well logging curves corresponding to water flooded zone, and have a systematic analyse. And on the basis of characteristic, achieved quality interpretation of water-flooded zone in region of interest. Finally, it is suitable to make use of gray relational theory for comprehensive evaluation between layers.