Research On The Mechanism Of Penetration In Gas Reservoir Under High Temperature And High Pressure And The Productivity Of Horizontal Well

In the development of high temperature and high pressure gas reservoir,the development of global offshore natural gas has been gradually promoted.According to incomplete statistics,the abnormal high pressure gas reservoir accounts for about 1/3.The high temperature and high pressure gas reservoirs in the sedimentary basins are abundant in the world.Due to the high temperature and pressure,the complex geological conditions and the changing of seepage,the exploration and development of natural gas in the region is a worldwide problem.Therefore,the study on the characteristics of high temperature and high pressure gas reservoir,the seepage mechanism,the distribution of temperature and pressure in the wellbore and the influence of the temperature and pressure changes on the gas well productivity becomes more and more important.Based on large number of domestic and foreign literature researches,this paper dwelled on researching the basic features for a gas reservoir,percolation mechanism and the temperature and pressure calculation model coupled horizontal well productivity model was studied.Firstly,the basic research and seepage mechanism of high temperature and high pressure gas reservoir to a high awareness of the presence of non-Darcy flow effect stress sensitivity,gas slippage effect and near wellbore formation,studied the influence of temperature on the porosity and permeability;Secondly,this paper considered the Joule Thompson effect,used energy conservation,material balance equation and momentum conservation law,established a high temperature and high pressure gas-water two-phase temperature and pressure coupling model,through the example data to verify the model;Secondly,the application of conformal transformation method,three-dimensional horizontal wells seepage into two-dimensional flow problem,consider the establishment of the reservoir to obtain stress sensitivity,gas slippage effect,near wellbore area high-speed non-Darcy flow effect,pressure gradient under the influence of a single-phase horizontal well productivity model;Furthermore,considered the effect of gas-water miscible seepage under high temperature and pressure conditions,the establishment of a new gas-water motion equation of gas-water two-phase generalized pseudo-pressure,and on the basis of capacity model single-phase horizontal wells,the deduced temperature;Finally,the horizontal wellbore is dispersed and the calculation program is compiled to couple the formation seepage with the wellbore flow to obtain the horizontal well in the high temperature and high pressure gas reservoir.The two-phase capacity coupling under the influence of temperature and pressure is considered.Used the example data verification utility and the accuracy of the production model,and Effects of air and water were analyzed with the production capacity of horizontal well productivity factors,we obtained the degree of influence of various factors on the energy gas wells.This paper obtained the temperature and pressure of gas water two-phase coupling model of a complete to meet the conditions of high temperature and high pressure,can effectively predict the wellbore temperature and pressure distribution,to provide reliable basic data analysis to high temperature and high pressure gas well production dynamic.