Study On Evaluation Of Development Effect And Productivity Prediction Method Of Thick Carbonate Reservoir

In this thesis,based on the BU reservoir in Iraq,the development effect evaluation and productivity prediction methods of thick carbonate reservoirs are studied.For the development effect evaluation of thick carbonate reservoirs,the block development indexes,including the water drive ultimate recovery rate,the draw on degree of water drive reserve,the pressure maintaining level,the production rate of remaining recoverable reserve,the comprehensive decline rate of annual oil production,the water cut rise rate,the cumulative injection-production ratio,the water storage rate and the water drive index,and single well development indexes,including the cumulative oil production in the last two years,the initial daily oil production,the daily average oil production,the water breakthrough time and the monthly average water cut rising value,are selected.The fuzzy comprehensive evalution theory,the principle of maximum membership degree and AHP are used to establish a comprehensive evaluation system for BU reservoir.According to the evaluation results,the overall development effect of BU reservoir is good.The reservoir development effect evaluation is to evaluate the current development status of the reservoir based on historical data of the reservoir,reflecting the current development situation of the reservoir.In order to adjust the reservoir development plan more effectively,it is also necessary to know the future developmet status of the reservoir,which requires research on the productivity prediction method of thick carbonate reservoirs.Based on the capacitance resistance model,this thesis considers the influences of edge water or bottom water invasion and oil-water saturation change in the process of oil-water seepage on the development indexes of oil wells,introduces the invasion speed and water dirve characteristic curve,and establishes a new model through the steps of prediction stage division,calculation of comprehensive fluidity coefficients in different stages,update of water injection distribution coefficients by comprehensive fluidity coefficient ratios and so on,so as to realize the prediction of oil well production.The results show that the average error of results predicted by the new model is less than 5%,which fully demonstrated the reliability of the prediction results of the new model.