Determination of steam quality in thermal injection wells
AssigneeShell Oil Company
InventorsBoyd B. Moore, Moye Wicks, III
Life of this patent
Estimating the term…
Abstract
A method and apparatus for measuring the quality rate of the steam injected into a hydrocarbon formation in a thermal recovery process. The method measures the density and flow rate of the steam downhole using a mechanical/electrical apparatus. The quality of the steam is calculated from the measured density and flow rate. The apparatus comprises an electric motor-generator and turbine wheel combination, the no-load speed of the motor being related to velocity of the steam while the stall torque is related to density of the steam.
Claims14
A method for determining the quality of the steam being injected into a hydrocarbon bearing formation surrounding a well in a thermal recovery process, said method comprising:
- positioning a bladed rotating member downhole;
- measuring the free rotational speed S.sub.o of the rotating member;
- measuring the torque T.sub.o required to stall the rotating member;
- determining the density of the liquid and vapor phases of the steam;
- determining the density .rho. of the steam from the expression T.sub.o =K*V.sup.2 *.rho. where K is a proportionality constant for a particular rotating member and V is the flow velocity of the steam;
- and
- determining the steam quality using the density .rho. and the density of the liquid and vapor phases.
An apparatus for determining the density of a two-phase flow of liquid and vapor comprising:
- a direct current motor-generator;
- a rotating member having at least one blade, said rotating member being secured to the shaft of said motor-generator;
- circuit means coupled to said motor-generator to both supply electrical power to the motor-generator and measure the rotational speed of the motor-generator;
- and
- means for mounting said motor-generator and rotating member in the two-phase flow to determine the speed versus load characteristics of the motor-generator.
A method for measuring two-phase flow and determining the percentage of each phase, said method comprising:
- positioning a combination rotating and drag member in the two-phase flow;
- measuring the free rotational speed of the member and the torque produced by the member at zero rotational speed;
- converting the measured rotation to velocity value;
- converting the measured torque to density value;
- and
- using the velocity and density values to determine the flow rate and percent of each phase in the two-phase flow.
Dependencies are inferred from the claim text.