Production Profile Interpretation Model And Its Software Development Based On DTS Data For Horizontal Well In Bottom Water Gas Reservoir

For horizontal gas wells,water production in a gas well will quickly cause its to be flooded.Therefore,the technology to find and plug water in horizontal gas well has become the key technology for efficiency gas reservoir development.However,the difficult to find water has become the main factor restricting the efficient development of gas reservoirs,how to find out the position of water in the horizontal well and then targeted to the implementation of water control measures?This is the thorny problem that plague the field production at present.With the rapid development of optical fiber technology in recent years,distributed optical fiber temperature measurement technology is becoming more and more mature,it can be used to test the temperature and pressure profile data of the horizontal well in a continuous and accurate way,then the distribution of the permeability of the horizontal well along the wellbore can be obtained by the inversion of the temperature and pressure profile.If the water production position can be found out,the difficulties,long time-consuming and high cost of the conventional production logging injection test can be avoided.Thus,this thesis studies the theory and method of the horizontal gas well production profile interpretation based on DTS data,which provides technical support for solving the difficulty of finding and controlling water in horizontal gas wells in oil fields for several years.Starting from the thermodynamic mechanism of gas reservoir and wellbore,and according to the law of pipe flow and seepage,on the basis of the law of conservation of mass,the law of conservation of momentum and the law of conservation of energy,the effects of thermal expansion,heat convection,heat conduction,viscous dissipation,Joule-Thomson effect and friction effect are considered.At the same time,the factors such as drilling skin,heterogeneity and non-Darcy effect are taken into consideration,the flow and thermod-ynamics models of wellbore and formation are established.On the basis of the above models,a coupled temperature forward prediction model between the formation and horizontal wellbore has been established,and the solving method and steps of the coupling model have been given.Then the effects of formation permeability,gas well production,horizontal well conditions(well diameter,wellbore roughness,etc.)and fluid properties on the results are analyzed.On the basis of the forward model,using the Levenberg-Marquardt(LM)algorithm and adaptive multi strategy differential evolution(SMDE)algorithm as well as temperature profile test data,the inversion models of horizontal well production profile were established.According to the temperature profile data and the average permeability of the formation,a set of method for calculating the initial value of the permeability distribution in the wellbore has been given,thus the efficiency of inversion is accelerated.In view of the characteristics of buttom water gas reservoir,a set of complete inversion interpretation process and method for horizontal well production profile is established.It lays the foundation for high efficiency to obtain the distribution of permeability along the horizontal well and the distribution of the wellbore production profile.Using the C Sharp(C#)language and the Visual Studio development environment,the interpretation software system is developed for the positive and inverse model.Then using the developed interpretation system software,the inversion interpretation of the permeability and production profile of a given horizontal well is calculated,the inversion results show that both the horizontal well temperature profile and the permeability distribution are in good agreement with the actual data,and the production profile interpretation results are also very accurate.The software of inversion interpretation is verified by the example data of the literature,the result shows that the software can make a good analysis of the contribution of each section of the horizontal well and the water production position.The results of this thesis can provide a new idea for comprehensive evaluation of horizontal well completion in domestic gas reservoir,it is of great practical significance to the popularization of DTS testing technology and the realization of the efficient development of gas reservoir.