Prediction Of Injection-Production Wells And Optimization Of Perforation Parameters For Controlling Production

After the oil field enters the period of medium and high water cut,the problem of water treatment becomes more and more serious.The separated water is pumped back into the oil layer by injection pump,while the oil-water mixture with higher oil content is lifted to the surface by production pump.But once we implement the channel sealing for the output layers,the liquid producing capacity of sealing channeling layers can not be judged,it can no longer be given reasonable proration of injection-production interval,the normal production in the process of the production string becomes not normal,and it is difficult to determine fluid producing ability after sealing channeling by using the method of logging.Therefore,it is necessary to study the fluid production capacity of injection-production wells after well sealing and channeling operation according to the method of reservoir engineering,so as to provide a theoretical basis for rational production allocation on site.In this paper,four kinds of conventional calculation methods are compared according to the actual situation in the field.It is found that because the selection of relevant data of the formation is relatively long and the accuracy of the data is difficult to guarantee,the four methods can not accurately predict the fluid production after sealing and channeling.Finally,IPR curve method was used to calculate the liquid yield after sealing and channeling by using Matlab or Pipesim software to fit with Vogel equation.And then,the paper uses formation coefficient method,test data injection method,IPR curve method,injection well bottom-hole pressure and production data to analyze the accuracy of the calculation fluid productivity index method.From the scene of the prediction accuracy of produced fluid volume and actual conditions,found by using IPR curve method to calculate the fluid productivity index and fluid producing are the most accurate and practical.At the same time,it is also clear that the bottom-hole pressure of adjacent injection well should be used as the boundary pressure when calculating the liquid production.After the IPR curve fitting method is used to determine the liquid yield,it is found that the sealing channel method is not enough to control the liquid yield.Therefore,the method of re-perforation is considered.Take layers of PI 1 and PI 2 of well B1-4-p44 for example,Comsol software is used for finite element analysis to simulate the influence of different perforation number and perforation density on the pressure drop in the near-well zone.Combined with the difference requirement between the actual liquid production and the expected liquid production,the number of re-perforations in PI1 and PI2 layers when the perforation diameter and perforation depth are 8.2mm and 436 mm,respectively,is calculated as 1 hole and 2 holes.It is also found that the perforation density has little influence on the pressure at 1m near the well radius under the same number of perforations.