The Research Of Automatic Identification Of The Connectivity In Injection-production System

Interwell connectivity of injection-production system is the connectivity between theinjection wells and production wells in water-flooding reservoir.It is largely significant forresearching the distribution of remaining-oil and adjusting the oilfield development plan.The traditional methods of the identification of the interwell connectivity requiresconstruction work which are difficult and costly to implement.These methods will alsointerfere with the normal production of the oil field.Inversion method based on oilfielddevelopment data and statistical algorithm got increasing attention because this kind ofmethod greatly reduces the cost of identification.But these methods either only considersone-sided factors or requires calculating large number of parameters.Currently, there is nomethods completely meet with success of application.This paper focused on the research about the automatic identification of interwellconnectivity on decision tree methods according to the actual situation of the Daqing Oilfieldand mainly studied the contents as follows:I. Based on the characteristics of the oilfield development data and the expertiseknowledge of geology, the paper puts forward a method to create the relative characteristicsbetween injection wells and production wells which can be used to build a decision treeclassification model of the identification of the connectivity in injection-production system.II. To solve overfitting problems,the paper proposed a kind of post-pruning strategywhich evenly considers classification accuracy, classification stability,and the scale ofdecision tree on the basis of in-depth study of the existing decision tree pruningalgorithm.Finally, this strategy is used to improve the decision tree classification model of theidentification of the interwell connectivity.III. The above-mentioned research is applied to the automatic identification of interconnectivity in the Daqing Oilfield. And a visualization application software is designed forthe correction of automatic identification result.According to the the practical application effect, the automatic identification method ofinterwell connectivity studied in this paper has the advantages of simple operation and fastdiscriminant.It improved the efficiency of identification and ensured a greater accuracy.