Gas Well Downhole Foam Flow Throttling Mechanism Research

With the advantages of foam drainage gas recovery technology such as low cost,simple operation and quick effect which becomes the first selection of drainage gas recovery.But because of some gas field gas well under common throttling mouth,to the implementation of the foam drainage gas recovery technology has brought a certain degree of limitation.Some throttle gas well after the foam drainage measures effect is very poor and even invalid,bubble row agent into flow in the wellbore has been very difficult to determine,after the existence of throttling mouth has resulted in a more complex flow law of wellbore,the gas bubble row of the implementation of the throttling process caused great difficulties.Throttling pressure drop model for air water two phase study more,but for bubble row throttling pressure drop model is very few,and there are a lot of model calculation bubble row throttling is conducted on the gas water model correction,and does not take into account the foam fluid and gas water throttling of different nature.On the basis of a large number of literature investigation,this paper carried out the gas conduit flow,bubble drain pipe flow,gas throttling and bubble row of throttling four categories a total of 105 groups of experiments,observe changes within the wellbore flow pattern,flow pattern,analysis the throttling mouth such as pressure,gas flow rate,liquid flow before and after test data,using two kind of different concentrations of bubble row and comparative experiments.Stress analysis of a single bubble,bubbles in the wellbore is arranged by considering the characteristics of a new kind of foam fluid density calculation model is established,through the new model of foam density correction throttling pressure drop model,using the experiment of Perkins model,Ashford model,Sachdeva model and bubble throttling correction model was evaluated,the selection of suitable for bubble fluid wellbore temperature distribution model and pressure distribution model,establish a bubble row throttling wellbore pressure and temperature field coupling model for calculation and verify the field data,compiled according to the bubble of downhole throttling theoretical calculation of typical chart.