Simulation Experiment Of New Drainage And Gas Recovery Technology In Horizontal Gas Well

The current drainage gas production process in the horizontal gas well is formed by the liquid backflow bottom,which not only loses the original gravity potential energy of the lifting liquid,but also reduces the gas production because of the increase of the back pressure of the stratum,and loses the liquid energy of the formation gas.In this paper,a new type of drainage gas production device is designed for this problem.In order to carry out the laboratory test,the device is partially simplified.On this basis,a new drainage gas extraction process simulation experiment for horizontal gas wells is carried out.The specific work is as follows:(1)To simplify the design of the new drainage gas production process,and to design the main parts of the process,and to build the physical simulation experiment device of the horizontal well by using the visual organic glass tube.The total length of the device is 13m.The inner diameter of the pipe is 50mm,and the inner wall is 5mm thick.There are pressure sensors around the nozzle at the vertical section,which provides data support for large diameter throttling experiment.(2)The air and water experiments of 14,16,18 and 20mm under the mouth diameter,gas flow rate 30～110m3/h and liquid flow rate 0.1～0.3m3/h were carried out by using the experimental device.Using the digital camera to capture the change of the flow state in the wellbore,the flow pattern and pressure change law of the air water experiment are analyzed,and the regularity of the reflux and the carrying law of the liquid are analyzed.(3)In order to study the liquid carrying capacity of the new device,the four droplet rate models of Wallis,Oliemans,Ishii-Mishima and Liu Tong model were evaluated by the experimental data of clear water,and the results of the four models were not quite different.The results of Liu Tong model were lower than those of the other three models.The average number of the predicted values of the four models was calculated,and the liquid film carrying rate was calculated.The multi parameter fitting of the liquid film carrying rate was carried out.Finally,the relationship between the liquid film carrying rate and the nozzle diameter,gas volume and liquid volume was finally obtained.(4)Using the experimental data to evaluate and optimize the two phase flow pressure drop model of the elbow section of the experimental device,and evaluate the best prediction effect of the Duns-Ros model,and use the Duns-Ros model to calculate the DXHW172 well in KLA beautiful gas field.(5)Developing field application,giving specific process parameters for target wells,and obtaining a complete set of process parameters for drainage and gas production.Based on the experimental setup,the experimental device is optimized and improved.Make the process more perfect.In this paper,a new type of drainage gas production device is designed to carry out a new type of drainage gas extraction experiment,which enriches the means of drainage and gas extraction technology,and has a certain reference value for the development of the new process of drainage gas production.