Measures In Well Selected Wells And Layers And Software Design

when the development of the flooding oil-field goes into the middle or late stage, the heterogeneity of reservoirs and the law of liquid flowing in porous media and the bad mobility ratio result in low sweep efficiency .all the aspects above lead the production wells to be early flooded by water so that the recovery is not high as expected .therefore ,the injection profile is improved by modification of highly permeable reservoirs of injection wells, which can increase the water sweep efficiency of these layers.in the end ,the aim to enhance the recovery is able to attained .before the implement of modification of injection profile,it is necessary to select the injection wells of the whole-oilfield .that is to say ,after those wells have been modified, the recovery will greatly be enhanced and the maximal economic benefit be gainedThe method to select the injection wells to be modified is composed of the method to choose the injection wells which is more suit to be modified than the others from multiple injection wells and the method to evaluate whether a single well should be modified or not. The first method comprises two type, one is the decision-making according to an index, the other is the decision-making using multiple indexes.The decision-making according to an index is done by applying those indexes that can reflect the heterogeneity and the rule that liquid flow in porous formations.after calculating the grade of membership of every index,engineer can choose injection wells which their the grade of membership is above the average .injection profile of these wells should be adjust.The decision-making using multiple indexes reflects all kinds of factors of injection wells. The first, reservoir engineers apply the method of fuzzy judgement to calculate the data completely thinking of all sorts of factors,then select the injection wells their value is above the average to modify injection profile.The method that single injection well is evaluated by fuzzy appraising is researched, after the evaluating standards of every index is constructed, the vector of evaluating every injection well can be gained by the fuzzy evaluation, the injection profile index is defined as the standard of choosing the injection wells to adjust theinjection profile, generally, the injection wells whose the injection profile index is bigger than 0.52 is selected to modify the injection profile.Effect predicting are as followe,first ,injection wells are classfied by the fuzzy mathematics.the classification considered the different importance of diverse factors. After the classification ,the symbol of the every type is founded out,given that injection profile of the symbol had been modified,engineer calculate the increment of rate and think of efficiency of the others as same as the symbol.Whether a production well should be fractured and acided or not is researched in this paper, to begin with, the indexes which are related to the penetrability of reservoirs,capacity of production of oil wells and the energy of formations should be discovered .the second ,these wells are appraised by fuzzy mathematics and the result of analysis will be gotten. The value that is above the average should be commonly fractured and acided.At the same time, the method that single production well is evaluated by fuzzy evaluation is researched. The quantification result can be precisely gained, after the evaluating standards of every index is constructed, the vector of evaluating every production well can be gained by the fuzzy evaluation, the fracturing and aciding index is defined . those production wells whose this index is bigger than 0.52 should be considered to be measured.The software for decision-making about selection of injection wells and oil wells have been developed. It can calculate the reserves according to dynamic production data. It also can divide the skin factor which is achieved by well testing into many parts.