Research On Flow Pattern Of Liquid In Variable Area Water Nozzle

Daqing Oilfield have entered extra high water cut production periodafter40years of waterflood development, oil field water injection havegradually developed into separate zone water injection and separateminilayer water injection and separate minilayer water injection and finewater injection from commingled water injection to satisfy the needs ofoil field develops.The diameter of traditional water nozzle in packer is fixed duringzonal injection. The water nozzle of the layer must be taken out if thediameter of the water nozzle is changed and corresponding injection rateis adjusted. Workload is large, and dropping and sticking accident occurseasily.Variable area water nozzle is studied in the paper, the section area ofwater crossing of the water nozzle can be changing when the water nozzleis downhole. Running and pulling is needless, testing efficiency isincreased much. Testing time is shortened, and the frequency of droppingand sticking is decreased during running and pulling.The variable relation between the rotation angle of variable areawater nozzle and the section area of water crossing is analyzed. Based onthe method of dimensional analysis, the criterion equation of flow of fluidthrough the variable area water nozzle is established. With the experiment data provided by oilfield and the criterion equation mentioned above, thecorrelation formula of pressure drop of flow of fluid through the variablearea water nozzle is obtained through the regression analysis usingmulti-variety linear regression program. The drawdown curves areplotted.The results mentioned above can guide optimum of the structuralsize and the flow parameters of the variable area water nozzle.