| Zhao25-58fault block belongs to the Zhou401oil block of Daqing oilfield.Zhao25-58is one of the firstly developed fault block reservoirs of Zhou401oil block, it was put into development in2006. Because of the low structure position the low oil saturation and a huge amount of reservoir water.The P15layers which well have a high range of SP number and a medium level RLLD number were not be perforated for producing. But as more related data have been gained and the accurate knowledge of geological structure have been done, coupled with the shutdown of a number of the high water cut wells in Zhao25-58fault block, it is really necessary to understand the P15layer and evaluate its property and productivity.in order to turn over the producing situation. So we need to do some P15layer reviews and measuring researches based on the5wells oil test in the Zhao25-58fault block and the principle of combining researching and implementation, and finally we get six results as following:· Zhao25-58fault block development zone is the Putaohua PI oil-bearing formation of the Cretaceous Yaojia period, it includes P15.P14.P13and P12four layers, the average reservoir porosity is19.4%. and the average permeability is37.8×10-3um2.· the Yanshan period nearly NS trending and Himalayan nearly East-West two kinds of faults are developed in the fault block, fault distance is typically30m, fault inclination angle is generally50to70degrees, the average depth of the reservoir is-1362m. the geological structure is characterized by the high south-west and the low north-east, there are still some micro structure related to geological activities in a few tiny fault blocks.· P15reservoir in the Zhao25-58fault block is a structural and lithological reservoir, the formation of the reservoir is controlled by both geological structure and lithology. But it is mainly influenced by lithology, and wells productivity is closed to the micro sedimentary facies.· The IP reservoir in the this block is characterized by high SP value, low oil saturation and high productivity, there is a stable interlayer compared to the upper P12,P13layer, and could be developed through layering.· P15layer is a typical shallow water delta front subfacies in this fault block, the subaqueous channel. river bar, sheet sand and front mud is present in the microfacies. and mainly subaqueous channel.the direction of material source is north-east, along Zhao25-58, well Zhoupu11-Xie75and Zhoupu19-Xie75through the whole fault block.· The work in the next step will be enforced according to the principle of mainly developing P15layer,and taking account of P12.P13layers and the entire program plan.9adjustment wells,5appraisal wells and25measures wells will be deployed. |
