The Logging Evaluation On Reservoir Of Donghe Sandstone In Donghe1Oilfield

Since1993when the oil pool has been developed, it has made great achievements and breakthrough in the reservoir of DongHe sandstone in DongHe1oilfield. Up to11,2011, there are40vertical wells in study area, of which the28production wells,12injection wells and12horizontal wells. Compared with existing reserves, it is added lots of drilling wells and obtained a mount of core data, testing data, logging data and so on. For stabilizing the output, adjusting development program, it is necessary to re-assess the calculating reserve parameters, re-calculate the oil initially in place of DongHe sandstone in the study area in order to obtain a more accurate geological oil reserves, guide the adjustment of development program, then reach the purposes of improving the recovery ratio of the oil field. In this paper, it is using the core data, geological data, testing data, logging data and so on to classify the sublayer, analyze the four features of reservoir, interpretate the reservoir parameter, identify the liquid and interbed and evaluate and classify the reservoir. Based on the above research results, it is re-assess the calculating reserves parameters and adopt the volumetric method to check and evaluate the oil initially in place.In this paper, it is classified and correlated the interbed using the core, logging data and so on, based on the results of the previous studies, according to depositional cycles and reservoir characteristic and taking the method of combining and correlating log. By collecting, arranging, correcting the core, test, logging data and so on of the DongHe sandstone in the study area and through drawing the cross plot, it is studied the lithology, physical property, electric property, hydrocarbon bearing property and the mutual relationship.On the basis that core scaled the log, taking the neural network method, it is established the neural network interpretation model of the reservoir for the vertical wells in the studied area and reached a higher interpretation accuracy. Using logging data, taking different method to establish the identifying standards for fluid, it is identified the fluid types in the study area and established the elevation of oil-gas contact in each well point. The research results shows that there is a uniform oil-water contact whose elevation is-4839m of DongHe Sandston in DongHe1oil field.Having lots of logging data of horizontal wells in the studied area, it is fully taken the advantage of horizontal well logging data in studied area to carry out the analysis of logging response characteristic of horizontal wells, summary the logging response characteristic of horizontal wells and present logging interpretation clue and method for reservoir parameter of horizontal wells, which means that correcting the log on the basis of analysis on the logging response characteristic of horizontal wells, it is made full use of core data of vertical wells and non-liner neural network model to establish the neural network interpretation model for the reservoir parameters of horizontal wells. By testing the results of the processing wells, it has achieved good effect.On the basis of classification and correlation of inerbed and fine interpretation on the reservoir parameters, analysis on core data and logging data, it is divided the interbed into three types of DongHe sandstone in studied area:muddy sandstone interbed, muddy lime interbed and limy sandstone interbed. Summarized the logging response characteristic and established the logging identification standards for interbed, it is identified the interbed and the distribution and the research on the affect that interbed in oil-gas moving.Finally, it is classified the reservoir of DongHe Sandstone into five types from the aspect of lithology, pore structure, physical property, feature bearing oil and so on the basis of above logging evaluation on reservoir in the studied area. After determining the reserves calculating parameters(oil-bearing area, effective net sand, effective porosity, oil saturation), it is taken the volumetric method to re-calculate the oil initially in place of DongHe sandstone in studied area. According the results of re-calculation, the identified oil initially in place is26.47million tons of DongHe sandstone in DongHe1oil field.