Study On The Capacity Of Gas Well Liquid Carrying By Physical Simulation

Formation water or condensate liquid produced in the development process for most of the gas reservoir in Sebei gas field. If the produced fluid can not be drainage in time, which caused bottom hole liquid loading, eventually led to gas well died. In the actual production, it is necessary to predict the critical points of liquid loading for gas well. Thus the working system can be timely adjusted or gas well normally production without liquid. However, with the continuation of the gas well development and the growing number of complex wells, such as the directional well, horizontal well,complex wells and so on, which led to the traditional model of critical liquid carrying flow rate lost its wide range of applicability.So the prediction results have a large difference as compared to the actual data, In addition, the liquid loading is inevitably because of gas reservoir pressure and gas well production decline. For liquid loaded in gas wells, it is a problem demanding resolved urgently in the field that how much volume of gas should be injected for liquid loading in gas wells discharging from the wellbore. Therefore, studying of the fluid-carrying capability and establishing the calculation model of critical liquid carrying flow rate and calculation model of critical gas stripping flow rate,which are universally applicable for the all kinds of gas well, have a very significance for the efficient development of water-producing gas wells.This paper conducts the following research in order to analyse the gas well liquid carrying capacity:(1) Investigated and compared all kinds of the calculation model of critical carrying fluid flow for vertical and inclined gas wells. And then, the relations and differences between the various models are summarized. The initial error analysis for each model that is combined with field data is conducted. On the basis of the analysis, two ideas for building a new liquid carrying model is proposed.(2) Critical carrying liquid simulation experiment for gas wells is promoted. The actual formation water regarded as a simulation liquid medium; compressed air regarded as the gas medium; plexiglass tube as an experimental pipe section are to achieve the purpose of visualization experiments. The pipe section installed with a pressure sensor, pressure drop sensor, flow meters and digital thermometers and other advanced equipment.(3) For specific experimental phenomenon and the experimental data analysis results, this paper selected ellipsoid model and the BF model as the basic model respectively. Experimental data fitting and correction method is adopted to build the calculation section model of critical carrying fluid flow for vertical and inclined gas wells. BF model as the basic model in combination with the whole correction method is selected to build unified critical carrying fluid flow calculation model for vertical and inclined gas wells which has a wide range of applicability. Using the Sebei gas wells field data conducted the error analysis of the applicability of the two models, and finally identified a new model that will be used to calculate gas wells’critical carrying fluid flow rate.(4) This paper has deduced the calculation model of critical gas stripping flow rate in theory. Conducted the simulation experiment of gas carrying the still liquid column, combining with specific experimental data to conduct error analysis for the equation. Finally, the error accuracy is in the allowable range of engineering, so the model can basically meet the engineering application needs.The paper established the new calculation model of critical carrying fluid flow rate, which can be used to calculate the critical carrying fluid flow rate for the vertical gas wells and horizontal gas wells. And the applicability is better than several traditional models, which are more suitable for the SeBei gas field production applications. The calculation model of critical gas stripping flow rate can guide to determine the minimum injection gas volume for loading liquid and flow back in gas wells reasonably. It has a high application value.