Researches On The Instrument Response Of Oil/gas/water Three Phase Flow In Vertical Wells

The daqing oilfield has already got into a high water cut stage, and most of productionwells produce nature gas, which cause oil, gas and water three-phase fluid distribute in oilwells and makes it difficult to production profile well logging.Aiming at the characteristic of response of flow rate and water cut measurement inthree-phase flow,the research was proposed in the paper. The device realizes the pipe sectionof oil gas water three phase flow measurement and control, as well as the oil gas waterseparation. Experimental device for simulating well pipe with the same diameter, internalimpedance watercut meter, conductivity correlation flowmeter and the turbine flowmeter anddifferential pressure density and temperature measuring sensor, each part uses short circuitconnection, used for measuring multiphase fluid flow, moisture content, temperature, pressureand other parameters.A special experiment equipment of three-phase flow in vertical well wasdesigned. The experiments adopted widely used impedance water holdup meter, turbine flowmeter and differential pressure density meter. The flow pattern and flow state of fluid flowingthrough the transparent pipe were recorded by high speed camera.Daqing oilfield development reservoir presents the oil-water two phase, gas water twophase condition, this thesis proposed three-phase flow apparatus separately completed theoil-water two phase, gas water two phase measurement response analysis. The results wereunder below.The experiment of turbine flow meter gas-water two phase flow shows that the turbineflow meter has different response regulations at low flow rate and high flow rate. When thewater flow rate is high and the gas flow rate is constant, the response of turbine flow rate isliner to the water flow rate.when the total flow rate is low, the response of turbine flow rate ismore sensitive to gas flow rate and when the gas flow rate is more than20m3/d, the turbineflow meter even losts its resolution.The experiment results of cross-correlation conductance flow meter in gas/water twophase flow have shown that the response of cross-correlation conductance flow meter can bevery good when the total flow rate above20m3/d. Otherwise the measurement results ofcorrelation flow meter are greatly affected by gas slippag when the total flow rate is lowerthan20m3/d. The experiment of the impedance water cut meter has shown that the response ofinstruments has a good relations to the watercut. The higher the flow rate is, the better theresolution is. In the water/oil two phase flow.the instruments response is only affected bywatercut and the more the total flow rate is, the better the response is Gas slippage effect willbecome more obvious along with the flow rate increasing.