Research On Development Evaluation And Remaining Oil Potential Tapping In Mideng Middle-low Porosity & Permeability Reservoir

In China, we are abundant in medium-low permeability oil and gas reservoirwhich have great potential of exploration and development. Both amount of the newproved reserves and the remaining oil and gas resource indicate that medium and lowpermeability oil and gas resources will become main object of the exploitation anddevelopment in the future and have important meaning to the national energy security.In this paper, the author used the theories of reservoir geology and engineering tostudy on the law of the development trend index and the reasonable value ofproduction index in the Mideng block. Because of the need of enhancing the effect ofsecondary exploitation, the theory for the evaluation of the block development systemand the effect of geological exploration was established by combining the method ofgray correlation and multiple correlation analysis method, and was used to finish thequalitative and quantitative analysis to the horizontal and longitudinal distribution ofthe remaining oil and had comprehensive adjustment research by combining thetheory with the commonly used measures of increasing production. The researchachievements mainly focus on the following five aspects.1. The research screened the development trend indicator by using the graycorrelation method, especially studying on the production decline, changes in watercontent and water injection utilization. The rule of single well production decline canbe divided into four different categories which are index, hyperbolic, harmonic andlinear. Composite water cut and recovery degree curve show S type curves whichillustrate that the block is good at storing water.2. Especially analyzed the indexes of measure effect, well pattern adaptation andreasonable injection-production and received the reasonable value. Fracturing andacidizing measures have best effect on cumulative oil production. After that areperforation adding and formation change. The value of water flooding controllingreserve is 0.5860 which is poor. The reasonable well spacing density of Mideng blockis 8.809/ km². The present Injection-Production Ratio is a little higher than the theoretical value, so the amount of injection water should be cut down.3. 7 indicators of evaluation of geological conditions and 8 indicators of theevaluation of development effects have been received by using the multiplecorrelation method. The weights of evaluation index of the development effect wereensured through combining the multiple correlation coefficient method and variationcoefficient method. Result of the calculation shows that the Mideng block still haspotential to increase its development effect.4. The qualitative analysis and quantitative calculation on remaining oildistribution have been finished by using a variety of reservoir engineering methods.Block recoverable reserves is relatively rich in the central block. The remainingrecoverable reserve is mainly concentrated in the central and western area. Vertically,the J₂^s2 layer has the most amount of remaining recoverable reserve.5. Research to development adjustment measures for improving developmenteffect. The formulating of integrated adjusting measures of improving the effect ofmiddle-low permeability reservoir development were based on the study of theremaining oil distribution, integrating commonly used measures of adjustment in thefield and analysis to the effect of enhancing development in terms of infill well,profile control and water shutoff and perforations adding.