Log Evaluation Of Low Permeability Reservoir Of The Third Member Of Funing Formation In The North Slope Of Gaoyou Depression

The north slope region of Gaoyou Depression is a new oil pool which was found by Jiangsu Oil Field in recent years, and it has prodigious developable potential. The third member of the Funing Formation 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 north slope 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 siltstone and thick mudstone. The sedimentary facies of the third member of the Funing Formation is mainly delta front and prodelta subfacies. Many reservoirs are medium porosity and medium-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 reservoir lithology, physical property, oil-bearing property and electronic characteristics, systematically analyzing reservoir four property correlations. On this basis, combined the actual situation of the north slope region, the study region is divided into Shanian, Huazhuang and Wazhuang region and separately establish suitable clay content and porosity, permeability, oil saturation parameters log interpretation model. Furthermore, porosity interpretation model of Shanian region is founded according to mouth bar, far dams and front sheet sand microfacies, 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 medium, partly strong. Finally, it is suitable to make use of gray relational theory for comprehensive evaluation between layers, and relatively high quality reservoirs are determined for the third member of the Funing Formation in the north slope region.