Logging Evaluation And Productivity Level Division Of Saertu And Putaohua Oil Layers In LX Area

Saertu and Putaohua oil layers in LX area are the focus of oil field exploration and development.They have the characteristics of high shale and calcium content,wide range of porosity and permeability,complex pore structure and sand-shale thin interbed series are widely distributed,which greatly increases the difficulty of reservoir logging evaluation and brings great difficulties to productivity level division.Therefore,it is very necessary to establish a set of quantitative interpretation and productivity level division method with the influence of shale and calcite.On the basis of various core analysis data and logging data,this paper analyzes the reservoir characteristics of Saertu and Putaohua oil layers in LX area by statistical analysis method.It is found that the reservoir porosity and permeability vary widely,the porosity is mainly distributed in 5%?30% and 3.3%?27.1%,the permeability is mainly distributed in 0.1m D?500m D;the shale content and calcium content of the reservoir are high,and the Sa?Pu oil layers shale content are mainly distributed In 5%?20%,the calcium content of Sa and Pu oil layers are mainly distributed in 0?15% and 0?5%,and some reservoirs can be up to 45%;and reservoir pore structure is complex,the average pore radius of the oil layers in Sa and Pu is mainly distributed in 1?10?m and 1?5?m.Formulas for shale content,calcium content,porosity,permeability,and irreducible water saturation of Saertu and Putaohua oil layers are established by using the method of statistical regression of core analysis data and neutron,density,sonic,micro-spherically focused and other logging data.Based on the study of influence of calcite on the law of rock conductivity,Indonesia equation is improved,and a saturation model for shale-rich and calcite-rich reservoirs is established.The calculation results are compared with core analysis and oil test results,the mode has high accuracy.According to the relationship between relative permeability and water cut,the calculation model of water cut in the study area is established.And based on the empirical formula of the relationship between relative permeability of oil and water and water saturation,the calculation model of relative permeability of Saertu and Putaohua reservoirs in the study area is determined by using the experimental data of core relative permeability in the study area.Using statistical analysis method,the effects of reservoir parameters,logging parameters,reservoir fluid parameters and engineering parameters on the productivity in Saertu ? Putaohua oil layers in the study area is analyzed,and the sensitive parameters of reservoir productivity are determined.On this basis,combining with the information of reservoir water cut,reservoir characteristics,logging data and oil testing data,the classification standard of reservoir productivity level is given,using productivity sensitive parameters,the composite parameters reflecting reservoir oil content,seepage capacity and fracturing effect are constructed,and then establish the classification plate of natural productivity and fracturing productivity of Saertu and Putaohua oil layers in the study area.Use the established interpretation method to process and interpret 33 wells in the study area.The productivity level of 140 layers in 33 vewells was determined by using the productivity level classification plate of Saertu and Putaohua reservoirs.Comparing the judgment results with the oil test results,the oil production grade coincidence rate is 76.4% and the water production grade coincidence rate is 73.6%,which proves that the established interpretation method is suitable for interpretation evaluation and productivity level classification of shale-rich and calcite-rich reservoirs in Saertu and Putaohua reservoirs in LX area.