Study On Reusable Potential For Long Time Shut-in Oil Wells

During the process of development in oil-fields, it has unavoidably caused to plenty of long time shut-in wells for various reasons. Closing oil/water Wells has caused serious problems, such as: many assets is standing idle; the injection and production rate is becoming imbalance; disproportion the drawing up on reserves, est., which has a bad direct effect on the production and recovery of the Oilfield. However, with the development of the Oilfield at Extra High Water Cut Stage, the adjustment of injection-production relation and the increasing rising of oil price, some of Long time closed-in oil wells has reusable potential now, therefore it is necessary to find out the value of them and make them product again.In order to judge the potential for long time shut-in oil wells, find out such oil wells bearing reused potential but inactive, and improve the economic returns, it is meaningful to study on the reusable potential for long time shut-in oil wells. In the paper, the causes of closing oil wells has been summed up and classified through in-depth study on the information of 314 long time shut-in oil wells of Putaohua Oilfield. Comprehensive reusable potential prediction models and relevant principles are established in order to reuse the potential of long time shut-in oil wells, considering economic efficiency and development conditions. The prediction model of redeveloping potential is based on Fuzzy Mathematics theory, which provides quantitative evaluation by calculating the redeveloping potential index. The prediction model of economic potential is based on the theory of economics profit and loss balance principle, which can determine the closing economic limitations of different stages of oil wells and predict whether a long time closed-in oil well has reusable economic potential or not. Based on the theory of marginal cost analysis and the combining mathematical statistics theory and multivariate linear regression, the mathematic model that can accurately forecast the measure potential is established.Applying the above prediction models, the paper select out the long time shut-in oil wells bearing reusable potential of Putaohua Oilfield. Based on the results of studying on the causes and the remaining reserves, bring up the reusing principles and measures of them, and do performance analysis and potential prediction of relevant measures. Fracturing programs of 4 long time shut-in oil wells has operated in Putaohua Oilfield, the results shows: the posttreatment effectivity is 100%, and it brought certain economic returns.