Extended isenthalpic and/or isothermal flash calculation for hydrocarbon components that are soluble in oil, gas and water

Patent metadata

Field	Value
Publication number	US-10767475-B2
Application number	US-201615557800-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Mar 23, 2015
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A method, apparatus, and program product to determine distribution of a plurality of components amongst a plurality of phases for a multi-component, multi-phase system including a multi-component, multi-phase fluid. A plurality of phase boundaries of the multi-component, multi-phase fluid and a vapor-liquid equilibrium (VLE) are determined based on a plurality of geophysical parameters associated with an oilfield and using one or more computer processors, including by determining hydrocarbon partitioning in a water phase, based in part on applying empirical equilibrium multi-phase mole fraction ratios (K-values) of the multi-component, multi-phase system that are functions of temperature and pressure only. In addition, an amount of at least one fluid component distributed in a plurality of phases of the multi-component, multi-phase system is predicted by solving a set of flash equations with the one or more computer processors based on the plurality of phase boundaries.

First claim

What is claimed is:

1. A method of determining distribution of a plurality of components among a plurality of phases for a multi-component, multi-phase system including a multi-component, multi-phase fluid, the method comprising:
determining a plurality of phase boundaries of the multi-component, multi-phase fluid and a vapor-liquid equilibrium (VLE) based on a plurality of geophysical parameters associated with an oilfield and using one or more computer processors, including determining hydrocarbon partitioning in a water phase, based in part on applying empirical equilibrium multi-phase mole fraction ratios (K-values) of the multi-component, multi-phase system that are functions of temperature and pressure only, wherein applying empirical equilibrium multi-phase mole fraction ratios of the multi-component, multi-phase system that are functions of temperature and pressure only includes, for a first hydrocarbon component in the multi-component, multi-phase fluid that is soluble in liquid, water and vapor phases:
applying a first empirical equilibrium multi-phase mole fraction ratio (K-value) for equilibrium between the liquid (L) and vapor (V) phases of the first hydrocarbon component; and
applying a second empirical equilibrium multi-phase mole fraction ratio (K-value) for equilibrium between the water (A) and vapor (V) phases of the first hydrocarbon component; and

predicting an amount of at least one fluid component distributed in a plurality of phases of the multi-component, multi-phase system by solving a set of flash equations with the one or more computer processors based on the plurality of phase boundaries.

2. The method of claim 1 , further comprising performing an oilfield operation based upon the predicted amount.

3. The method of claim 1 , further comprising modeling an oilfield operation using at least one computer-implemented simulator, wherein at least a portion of the oilfield is represented by a plurality of grid blocks in the simulator, wherein the plurality of phase boundaries are determined and the amount of the at least one fluid component distributed in the plurality of phases is predicted for each of the plurality of grid blocks.

4. The method of claim 3 , further comprising determining phase states, phase splits, and phase mole fractions associated with each of the plurality of grid blocks.

5. The method of claim 1 , wherein determining hydrocarbon partitioning is based in part on phase behavior and enthalpy of water described by a steam table that is a function of temperature and pressure.

6. The method of claim 1 , wherein the plurality of geophysical parameters includes geophysical parameters selected from the group consisting of global mole fractions of one or more volatile hydrocarbon (VHC) components of oil, global mole fractions of one or more non-volatile hydrocarbon (NVHC) components of oil, global mole fractions of one or more non-condensable hydrocarbon (NCHC) components of oil, global mole fractions of one or more water components, a pressure of the inlaid-component, multi-phase fluid, an enthalpy of the multi-component, multi-phase fluid, a temperature of the multi-component, multi-phase fluid, a fluid phase saturation, a fluid phase density, a component density, and a component fraction by volume or mole in a particular phase.

7. The method of claim 1 , wherein determining the plurality of phase boundaries includes:
determining at least one first temperature at which a first liquid phase associated with the plurality of phase boundaries disappears;
determining at least one second temperature at which a second liquid phase associated with the plurality of phase boundaries disappears; and
determining at least one third temperature at which the gaseous phase appears.

8. The method of claim 7 , wherein the first liquid phase is present when the second liquid phase disappears, wherein the second temperature is determined based on the first temperature and is lower than or equal to the first temperature, wherein the third temperature is determined based on the second temperature and is lower than or equal to the second temperature, and wherein the at least one first, at least one second, and at least one third temperatures are determined in part by using pressure and temperature dependent empirical equilibrium multi-phase mole fraction ratios (K-values) of the multi-component, multi-phase system.

9. The method of claim 7 , wherein determining the plurality of phase boundaries includes determining a succession of temperatures where a liquid phase may disappear and/or reappear one or more times.

10. The method of claim 7 , further comprising one or both of determining at least one temperature at which an additional liquid phase disappears or determining at least one temperature at which an additional gaseous phase appears.

11. The method of claim 7 , wherein determining the at least one first temperature at which the first liquid phase disappears includes determining the at least one first temperature at which oil disappears before water.

12. The method of claim 7 , wherein determining the at least one first temperature at which the first liquid phase disappears includes determining the at least one first temperature at which water disappears before oil.

13. The method of claim 1 , wherein predicting the amount of an at least one fluid component distributed in a plurality of phases of the multi-component, multi-phase system includes predicting the amount of a hydrocarbon component in liquid, water and gas phases.

14. An apparatus, comprising:
one or more computer processors; and
a memory having instructions that when executed by the one or more computer processors determine distribution of a plurality of components among a plurality of phases for a multi-component, multi-phase system including a multi-component, multi-phase fluid, the instructions including:
instructions to determine a plurality of phase boundaries of the multi-component, multi-phase fluid and a vapor-liquid equilibrium (VLE) based on a plurality of geophysical parameters associated with an oilfield, including instructions to determine hydrocarbon partitioning in a water phase, based in part on applying empirical equilibrium multi-phase mole fraction ratios (K-values) of the multi-component, multi-phase system that are functions of temperature and pressure only, wherein applying empirical equilibrium multi-phase mole fraction ratios of the multi-component, multi-phase system that are functions of temperature and pressure only includes, for a first hydrocarbon component in the multi-component, multi-phase fluid that is soluble in liquid, water and vapor phase;
applying a first empirical equilibrium multi-phase mole fraction ratio (K-value) for equilibrium between the liquid (L) and vapor (V) phases of the first hydrocarbon component; and
applying a second empirical equilibrium multi-phase mole fraction ratio (K-value) for equilibrium between the water (A) and vapor (V) phases of the first hydrocarbon component; and

instructions to predict an amount of at least one fluid component distributed in a plurality of phases of the multi-component, multi-phase system by solving a set of flash equations based on the plurality of phase boundaries.

15. A program product, comprising:
a non-transitory computer readable medium; and
program code stored on the non-transitory computer readable medium and configured upon execution by one or more computer processors to determine distribution of a plurality of components among a plurality of phases for a multi-component, multi-phase system including a multi-component, multi-phase fluid, t

Assignees

• Schlumberger Technology Corp
• Chevron Usa Inc
• Total Sa

Inventors

• Stone Terry Wayne
• Chang Yih-Bor
• Bennett James

Classifications

• E21B43/00 Primary

  Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) · CPC title

• E21B2200/20

  Computer models or simulations, e.g. for reservoirs under production, drill bits · CPC title

• G01V1/48

  Processing data · CPC title

• G06F17/10

  Complex mathematical operations {(function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544)} · CPC title

• E21B43/16 Primary

  Enhanced recovery methods for obtaining hydrocarbons · CPC title