METHOD AND DEVICE FOR REAL-TIME ACOUSTIC MONITORING PROPERTIES OF FOAM AND AERATED LIQUIDS Russian patent published in 2009 - IPC E21B47/00 G01N29/00 

FIELD: physics; measurement.

SUBSTANCE: present invention pertains to the method and device for real time acoustic monitoring properties of foam and aerated multiphase liquids with complex rheology. The method and device can be used for determining gas content in liquids containing gas, particularly in the oil industry, when servicing wells, as well as cementing wells or hydraulic fracturing. For acoustic monitoring quality of foam, at least one emitter-receiver pair is placed in close proximity to the stream of foam and at least one acoustic pulse is emitted. The time for which the acoustic pulse travels from the emitter to the receiver is recorded, and the speed of the acoustic pulse (speed of sound) is determined by analysing acoustic response of the receiver. Pressure in the foam in the region between the emitter and the receiver is then determined and the quality G, of the foam is calculated from the equation: where C_fm is the speed of sound in the foam, p is pressure, ρ_fi is the density of the liquid, G is the quality of foam, and N is the polytropic expansion coefficient. N=1 for an isothermal process. N=1.4 for an adiabatic process if the foam consists of an ideal gas and an ideal fluid. If the quality of foam is considerably less than ½ or considerably greater than ½, choice of the sign in the formula should be "-" and "+" respectively, and if both values of G are close to ½, both quality values should be considered possible. In more complex situations, the quality value is found from a table of values.

EFFECT: increased efficiency of acoustic monitoring quality of foam in real time.

10 cl, 11 dwg