A New Method And Its Application Of Steamlfooding Dynamic Prediction

Steamflooding is the most widely applied and best economic technique for heavy oilreservoirs. When switching to steamflooding, it is the main issue that how to realize therational development of oilfield and scientific management, which should be faced by oil fieldworkers. In addition to the numerical simulation method for predicting dynamic production ofsteamflooding, there are the experience formula method and analytical model method.Although the accuracy of numerical simulation is higher, the numerical simulation needsmore workload and investment. It is almost impossible to simulate strictly reservoirconditions by analytical model. The method used commonly is to simplify the acturalconditions to simulate some extreme oil production process, and up to now there are aboutscores of the models formed.On the basis of summarizing the research progress of dynamic steamflooding productionprediction, this paper briefly studies some theories about heat conduction and convection heattransfer in and near the pay layer, gives some heat conduction equations for heat diffusionarea and steam frontier and some formulas to calculate heat efficiency for steam injection.This paper does some research for Jones model and Miller-Leung model respectively,gives the computer programs of both models, and fits the oilfield production history data byusing the programs. The result shows that there are two conclusions from the prediction resultof Jones model:(1) the predict result of oil production speed will soon reach a maximum, andthen decrease with a bit gentle speed;(2) for cumulative production, the difference betweenpredict result and actural data is large at the beginning, and the difference will be smaller overtime. The prediction result of oil production speed is a smooth curve through the applicationof Miller-Leung’s model, and there is no such maximum inflection point as Jones’steamflooding model in the curve.By upgrading the methods of both Jones model and Miller-Leung model, this paperestablishes a new method to predict steamflooding dynamic production by using Vectormethod to analyse dynamic changes of the interface between steam and fluid duringsteamflooding process, and gives computer program of the new method. The prediction resultof the new method is more anastomosis with the field data, and it can be used for the dynamicprediction of production.The adjustment coefficient used in the new method of steamflooding dynamic productionprediction can act as an assistant tool to judge the means of production. When the adjustmentcoefficient q>0.5, steamflooding should be given priority as a method for reservoirdevelopment; When q<0.5, it is suggested other methods should be used to develop thereservoir, and gravity drainage is the main mechanism for such methods.