Multiphase flow calculation software
AssigneeBechtel BWXT Idaho, LLC
InventorJames R. Fincke
Life of this patent
Estimating the term…
Abstract
Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.
Claims51
In a computer in communication with a differential pressure flow meter having at least three pressure measuring points, the first pressure measuring point being located at an entrance of the differential pressure flow meter, a second pressure measuring point being located at a proximal end of the extended throat, and a third pressure measuring point being located at a distal end of the extended throat, and the differential pressure flow meter further including an interior wall and having a contraction and an extended throat, a method for determining a flow rate of a liquid phase and a gas phase of a multiphase flow, the method comprising the steps for:
- (a) determining a density rhogw of the gas phase of the multiphase flow;
- (b) determining a normalized gas phase mass flow rate mgm;
- (c) determining an actual gas phase mass flow rate mg based upon said normalized gas phase mass flow rate mgm and said density rhogw;
- (d) determining a gas phase velocity ug in the extended throat based upon said actual gas phase mass flow rate mg;
- (e) determining a pressure drop ΔPgl3 experienced by the gas phase in accelerating the liquid phase between the first and third pressure measuring points based upon said density rhogw and said estimated gas phase velocity ug;
- (f) determining a liquid phase velocity ul in the extended throat based upon a wall friction constant gcfw and said pressure drop ΔPgl3;
- (g) determining friction between the liquid phase and the interior wall based upon said wall friction constant gcfw and said estimated liquid phase velocity ul;
- and
- (h) determining a mass flow rate mt of the multiphase flow based upon said friction f and said estimated gas phase velocity ug.
In a computer in communication with a differential pressure flow meter having at least three pressure measuring points, the first pressure measuring point being located at an entrance of the differential pressure flow meter, a second pressure measuring point being located at a proximal end of the extended throat, and a third pressure measuring point being located at a distal end of the extended throat, and the differential pressure flow meter further including an interior wall and having a contraction and an extended throat, a method for determining a flow rate of a liquid phase and a gas phase of a multiphase flow, the method comprising the acts of:
- (a) calculating a density rhogw of the gas phase of the multiphase flow using a reference gas density rhog, a pressure P of the multiphase flow at the entrance of the differential pressure flow meter, and a temperature T of the multiphase flow at the entrance of the differential pressure flow meter;
- (b) calculating a normalized gas phase mass flow rate mgm using experimentally determined constants A, B, and C, a measured pressure differential ΔP3 across the contraction, and a measured pressure differential ΔP2 across the extended throat;
- (c) calculating an actual gas phase mass flow rate mg using said normalized gas mass flow rate mgm, an area At of the extended throat in square inches, a contraction ratio β, and said density rhogw of the gas phase;
- (d) estimating a gas phase velocity ug in the extended throat using said actual gas phase mass flow rate mg, said reference gas density rhog, and said area At of the extended throat;
- (e) calculating a pressure drop ΔPgl3 experienced by the gas phase in accelerating the liquid phase between the first and third pressure measuring points, using said measured pressure differential ΔP3 across the contraction, said gas phase density rhogw, said estimated gas phase velocity ug in the extended throat, and said contraction ratio β;
- (f) estimating a liquid phase velocity ul in the extended throat using said measured pressure differential ΔP3 across the contraction, said pressure drop ΔPgl3, a density rhol of the liquid phase, a wall friction constant gcfw, and said contraction ratio β;
- (g) calculating friction f between the interior wall and the liquid phase using said wall friction constant gcfw, said density rhol of the liquid phase, and said estimated liquid phase velocity ul in the extended throat;
- and
- (h) calculating the mass flow rate mt of the multiphase flow using said measured pressure differential ΔP3 across the contraction, said contraction ratio β, said estimated gas phase velocity ug in the extended throat, said area At, and said friction f.
In a computer in communication with a differential pressure flow meter having at least three pressure measuring points, the first pressure measuring point being located at an entrance of the differential pressure flow meter, a second pressure measuring point being located at a proximal end of the extended throat, and a third pressure measuring point being located at a distal end of the extended throat, and the differential pressure flow meter further including an interior wall and having a contraction and an extended throat, a computer program product for implementing a method for determining a flow rate of a liquid phase and a gas phase of a multiphase flow, the computer program product comprising:
- a computer readable medium carrying computer executable instructions for performing the method, wherein the method comprises the steps for:
- (a) determining a density rhogw of the gas phase of the multiphase flow;
- (b) determining a normalized gas phase mass flow rate mgm;
- (c) determining an actual gas phase mass flow rate mg based upon said normalized gas phase mass flow rate mgm and said density rhogw;
- (d) determining a gas phase velocity ug in the extended throat based upon said actual gas phase mass flow rate mg;
- (e) determining a pressure drop ΔPgl3 experienced by the gas phase in accelerating the liquid phase between the first and third pressure measuring points based upon said density rhogw and said estimated gas phase velocity ug;
- (f) determining a liquid phase velocity ul in the extended throat based upon a wall friction constant gcfw and said pressure drop ΔPgl3;
- (g) determining friction between the liquid phase and the interior wall based upon said wall friction constant gcfw and said estimated liquid phase velocity ul;
- and
- (h) determining a mass flow rate mt of the multiphase flow based upon said friction f and said estimated gas phase velocity ug.
In a computer operatively connected to a differential pressure flow meter including an interior wall and having a contraction and an extended throat, and wherein a first pressure measuring point is located upstream of the differential pressure flow meter, a second pressure measuring point is located at a proximal end of the extended throat, and a third pressure measuring point is located at a distal end of the extended throat, a computer program product for implementing a method for determining a flow rate of a liquid phase and a gas phase of a multiphase flow, the computer program product comprising:
- a computer readable medium carrying computer executable instructions for performing the method, wherein the method comprises the acts of:
- (a) calculating a density rhogw of the gas phase of the multiphase flow using a reference gas density rhog, a pressure P of the multiphase flow at the entrance of the differential pressure flow meter, and a temperature T of the multiphase flow at the entrance of the differential pressure flow meter;
- (b) calculating a normalized gas phase mass flow rate mgm using experimentally determined constants A, B, and C, a measured pressure differential ΔP3 across the contraction, and a measured pressure differential ΔP2 across the extended throat;
- (c) calculating an actual gas phase mass flow rate mg using said normalized gas mass flow rate mgm, an area At of the extended throat in square inches, a contraction ratio β of said extended throat area At to the entrance area A0, and said density rhogw of the gas phase;
- (d) estimating a gas phase velocity ug in the extended throat using said actual gas phase mass flow rate mg, said reference gas density rhog, and said area At of the extended throat;
- (e) calculating a pressure drop ΔPgl3 experienced by the gas phase in accelerating the liquid phase between the first and third pressure measuring points, using said measured pressure differential ΔP3 across the contraction, said gas phase density rhogw, said estimated gas phase velocity ug in the extended throat, and said contraction ratio β;
- (f) estimating a liquid phase velocity ul in the extended throat using said measured pressure differential ΔP3 across the contraction, said pressure drop ΔPgl3, a density rhol of the liquid phase, a wall friction constant gcfw, and said contraction ratio β;
- (g) calculating friction f between the interior wall and the liquid phase using said wall friction constant gcfw, said density rhol of the liquid phase, and said estimated liquid phase velocity ul in the extended throat;
- and
- (h) calculating the mass flow rate mt of the multiphase flow using said measured pressure differential ΔP3 across the contraction, said contraction ratio β, said estimated gas phase velocity ug in the extended throat, said area At, and said friction f.
In a computer operatively connected to a differential pressure flow meter including an interior wall and having a contraction and an extended throat, and wherein a first pressure measuring point is located upstream of the differential pressure flow meter, a second pressure measuring point is located at a proximal end of the extended throat, and a third pressure measuring point is located at a distal end of the extended throat, a method for determining a flow rate of a liquid phase and a gas phase of a multiphase flow originating from a well, the method comprising the acts of:
- (a) calculating a density rhogw of the gas phase of the multiphase flow using the equation:
- rho gw = rho g ( P + 14.7 14.7 ) ( 60 + 459.67 T + 459.67 )
- wherein,
- rhog is methane density at standard temperature and pressure for a specific well;
- P is a pressure of the multiphase flow at the entrance of the multiphase flow meter;
- and
- T is a temperature of the multiphase flow at the entrance of the multiphase flow meter;
- (b) calculating a normalized gas phase mass flow rate mgm using the equation:
- mgm=A+B{square root over (Δ)}P3+C{square root over (Δ)}P2
- wherein,
- A, B, and C are experimentally determined constants required to calculate gas phase mass flow rate;
- ΔP3 is a measured pressure differential across the contraction;
- and
- ΔP2 is a measured pressure differential across the extended throat;
- (c) calculating an actual gas phase mass flow rate mg using the equation:
- m g = mgm · A t · rho gw 1 - β 4
- wherein,
- mgm is the normalized gas phase mass flow rate;
- At is an area of the extended throat;
- and
- β is a contraction ratio of At to the entrance area A0;
- (d) estimating a gas phase velocity ug in the extended throat using the equation:
- u g = m g rho g · A t
- wherein,
- mg is the gas phase mass flow rate;
- rhog is a gas phase density for a specific well;
- and
- At is an area of the extended throat;
- (e) calculating a pressure drop ΔPgl3 experienced by the gas phase in accelerating the liquid phase between the first and third pressure measuring points,
- using the equation:
- Δ P g13 = - Δ P 3 - 1 2 · rho gw · u g 2 · ( 1 - β 4 )
- wherein,
- ΔP3 is a measured pressure differential across the contraction;
- rhogw is the gas phase density at the well;
- ug is the gas phase velocity in the extended throat;
- and
- β is a contraction ratio of At to the entrance area A0;
- (f) estimating a liquid phase velocity ul in the extended throat using the equation:
- u 1 = 2 ( Δ P 3 - Δ P g13 ) rho 1 · [ ( 1 + β 4 ) + gcfw ]
- wherein,
- ΔP3 is a measured pressure differential across the contraction;
- ΔPgl3 is the pressure drop experienced by the gas phase due to work performed by the gas phase on the liquid phase;
- rhol is the liquid phase density;
- and
- gcfw is a wall friction constant;
- (g) calculating friction f between the interior wall and the liquid phase using the equation:
- f = gcfw · 1 2 · rho 1 · uu 1 2
- wherein,
- gcfw is a wall friction constant;
- rhol is the liquid phase density;
- and
- ul is the estimated liquid phase velocity in the extended throat;
- and
- (h) calculating the mass flow rate mt of the multiphase flow using the equation:
- m t = 2 ( Δ P 3 - f ) ( 1 - β 4 ) · u g · A t
- wherein,
- ΔP3 is a measured pressure differential across the contraction;
- β is a contraction ratio of At to the entrance area A0;
- and
- ug is the estimated gas phase velocity in the extended throat.
In a computer operatively connected to a differential pressure flow meter including an interior wall and having a contraction and an extended throat, and wherein a first pressure measuring point is located upstream of the differential pressure flow meter, a second pressure measuring point is located at a proximal end of the extended throat, and a third pressure measuring point is located at a distal end of the extended throat, a method for determining a flow rate of a liquid phase and a gas phase of a multiphase flow originating from a well, the method comprising the acts of:
- (a) calculating a density rhogw of the gas phase of the multiphase flow using the equation:
- rho gw = rho g ( P + 14.7 14.7 ) ( 60 + 459.67 T + 459.67 )
- wherein,
- rhog is methane density at standard temperature and pressure for a specific well;
- P is a pressure of the multiphase flow at the entrance of the multiphase flow meter;
- and
- T is a temperature of the multiphase flow at the entrance of the multiphase flow meter;
- (b) calculating a normalized gas phase mass flow rate mgm using the equation:
- mgm=A+B{square root over (Δ)}P3+C{square root over (Δ)}P2
- wherein,
- A, B, and C are experimentally determined constants required to calculate gas phase mass flow rate;
- ΔP3 is a measured pressure differential across the contraction;
- and
- ΔP2 is a measured pressure differential across the extended throat;
- (c) calculating an actual gas phase mass flow rate mg using the equation:
- m g = mgm · A t · rho gw 1 - β 4
- wherein,
- mgm is the normalized gas phase mass flow rate;
- At is an area of the extended throat;
- and
- β is a contraction ratio of At to the entrance area A0;
- (d) estimating a gas phase velocity ug in the extended throat using the equation:
- u g = m g rho g · A t
- wherein,
- mg is the gas phase mass flow rate;
- rhog is a gas phase density for a specific well;
- and
- At is an area of the extended throat;
- (e) calculating a pressure drop ΔPgl3 experienced by the gas phase in accelerating the liquid phase between the first and third pressure measuring points,
- using the equation:
- Δ P g13 = - Δ P 3 - 1 2 · rho gw · u g 2 · ( 1 - β 4 )
- wherein,
- ΔP3 is a measured pressure differential across the contraction;
- rhogw is the gas phase density at the well;
- ug is the gas phase velocity in the extended throat;
- and
- β is a contraction ratio of At to the entrance area A0;
- (f) estimating a liquid phase velocity ul in the extended throat using the equation:
- u 1 = 2 ( Δ P 3 - Δ P g13 ) rho 1 · [ ( 1 + β 4 ) + gcfw ]
- wherein,
- ΔP3 is a measured pressure differential across the contraction;
- ΔPgl3 is the pressure drop experienced by the gas phase due to work performed by the gas phase on the liquid phase;
- rhol is the liquid phase density;
- and
- gcfw is a wall friction constant;
- and
- (g) calculating a mass flow rate ml of the liquid phase using an equation:
- ml=(1−α)·rhol·ul·Apipe
- wherein,
- α is a measured void fraction of the multiphase flow;
- rhol is a liquid phase density;
- ul, is a liquid phase velocity;
- and
- Apipe is a cross-sectional area of a conduit wherein said void fraction is measured.
Dependencies are inferred from the claim text.