Characterization Method And Application Of The Heating Range Of Multi-thermal Fluid Huff And Puff For Heavy Oil

As an effective method of increasing heavy oil production and enhancing oil recovery,the multi-thermal fluid stimulation technology has achieved good application effect in the field.However,compared with steam huff and puff,its heat transfer mechanism and fluid composition are more complex,so the effective characterization of its heating shape is very important for the calculation of its heating area,the evaluation of its production capacity and the formulation of the subsequent development plan.In this paper,the injection of multi-thermal fluid through the horizontal well is taken as the research object.Firstly,the two-dimensional heating shape along the horizontal well profile is characterized.Considering the influence of overlap caused by density contrast between injected fluids and formation fluids,the local thermal equation,momentum conservation equation and other balance equations are established.The heating shape under the conditions of hot water and steam based multi-thermal fluid are characterized and solved respectively.A further sensitivity analysis of the heating shape with different parameters is made.Then,on the premise of considering the coupling relationship between the formation and wellbore and variable mass flow,the mass transfer and heat transfer model along the wellbore is established,and the thermal physical parameters such as pressure,temperature and fluid parameters are accurately solved by node analysis method and iterative method,and a new method for calculating the heating area is proposed.Then,based on the theoretical results of those two models,the relevant formulas for productivity calculation in different heat injection stages are derived.In addition,a new piece of calculation software has been developed and the accuracy of the software calculation results under the condition of actual oilfield parameters was verified.Finally,from four aspects including non-condensable gas composition,injection rate and multi-thermal fluid composition,the influence rules of different parameters on the development effect are discussed,so as to provide theoretical and computational basis for the field injection production parameter setting and development plan formulation.The theoretical model and software achievements of this paper have certain practical guiding significance for the actual production of the mine.