Thin Layer Of Well Logs. Correction Method And Reservoir Identification Model Study

At present, the thin layer oil output has already become the main oil producing zones in many oil field of china. But the log values often fail to get high-precision because log values are subject to several environment effects and in particular shoulder bed effect. At the same time, recognizing the oil-gas-water bed exactly is offering important basic data for the disposition and planning of development. How to solve these problems will have a very important guiding meaning.Based on the principle of density log, nature gamma-ray log and resistivity log, shoulder bed correction methods to each one are made. Then PNN model is used to recognize the oil-gas-water bed. The systemic method fit for thin layer and model of recognizing the oil-gas-water bed is accomplished.Improving vertical resolution for density curves is by means of restructuring the response from large and small spacing sondes and borehole effect correction factor and coherence factor are used. Form the principle of GR logging, calculate volumes in investigating areas taken by borehole, formation, up and low shoulder beds, along with distance between center of gravity of the four unit bodies and detector. Based on the above, the weighting function of each unit body to GR signal contributions are established, thus realizing processing of GR logs with high resolution. The resistivity logging model uses "resolution matching" method to improve the resolution of the logs. After the process, PNN model is made to recognize the oil-gas-water bed. Compared with BPNN, the net work is featured swiftness, accuracy and ease of practical application.