Experimental device and method for solubility determination of methane in oil-based drilling fluid

Patent metadata

Field	Value
Publication number	US-12332231-B2
Application number	US-202318346259-A
Country	US
Kind code	B2
Filing date	Jul 2, 2023
Priority date	Apr 24, 2023
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

Disclosed is an experimental device and method for solubility determination of methane in oil-based drilling fluid, comprising a pressure-resistant gas chamber and an equilibrium still both arranged in a constant-temperature oil bath heating oven, a gas booster pump, and a vacuum system used for vacuuming the pressure-resistant gas chamber and the equilibrium still, and a data acquisition device for collecting temperature and pressure signals; the gas booster pump is connected to drive air source inlet, a gas check valve is arranged on the pipe between the pressure-resistant gas chamber and the gas booster pump that is also connected with a high-pressure gas cylinder, the equilibrium still is divided into a dissolution equilibrium chamber at the top and a hydraulic oil chamber at the bottom by a high-pressure dynamic seal structure, the dissolution equilibrium chamber is connected to a liquid inlet funnel through the fourth globe valve.

First claim

What is claimed is:

1. An experimental device for solubility determination of methane in oil-based drilling fluid comprises; a pressure-resistant gas chamber ( 15 ) and an equilibrium still ( 25 ) both arranged in a constant-temperature oil bath heating oven ( 26 ), and a gas booster pump ( 4 ) connected to the pressure-resistant gas chamber ( 15 ), wherein the gas booster pump ( 4 ) is connected to drive air source inlet ( 5 ), a gas check valve ( 10 ) is arranged on a pipe between the pressure-resistant gas chamber ( 15 ) and the gas booster pump ( 4 ), the gas booster pump ( 4 ) is also connected with a high-pressure gas cylinder ( 1 ), the equilibrium still ( 25 ) is divided into a dissolution equilibrium chamber at the top and a hydraulic oil chamber ( 27 ) at the bottom by a high-pressure dynamic seal structure ( 20 ), the dissolution equilibrium chamber is connected to a liquid inlet funnel ( 21 ) through the fourth globe valve ( 22 ), and the hydraulic oil chamber ( 27 ) is connected to a high-pressure metering pump ( 23 ) for replenishing hydraulic oil inside; wherein the experimental device further comprises a vacuum system ( 30 ) used for vacuuming the pressure-resistant gas chamber ( 15 ) and the equilibrium still ( 25 );
wherein a first temperature sensor ( 13 ) and a first pressure sensor ( 14 ) are provided in the pressure-resistant gas chamber ( 15 ) for collecting temperature and pressure signals; a second temperature sensor ( 17 ) and a second pressure sensor ( 24 ) are provided in the dissolution equilibrium chamber for collecting temperature and pressure signals; the first temperature sensor ( 13 ), the first pressure sensor ( 14 ), the second temperature sensor ( 17 ), and the second pressure sensor ( 24 ) are connected to the data acquisition device ( 31 ).

2. The experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , wherein a gas filter ( 6 ), a first relief valve ( 7 ), a second pressure gauge ( 8 ) and an electric valve ( 9 ) are installed on the pipe between the air source inlet ( 5 ) and the gas booster pump ( 4 ).

3. The experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , the experimental device further comprises a first pressure gauge ( 2 ) for measuring the pressure of the high-pressure gas cylinder ( 1 ) and a first globe valve ( 3 ) for controlling its switch.

4. The experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , wherein the pipe between the pressure gas chamber ( 15 ) and the gas booster pump ( 4 ) is also provided with a second relief valve ( 11 ) and a second globe valve ( 12 ).

5. The experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , wherein an agitator blade ( 19 ) for agitation is set inside the dissolution equilibrium chamber, and is connected with an agitator motor ( 18 ).

6. The experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , wherein the vacuum system ( 30 ) is composed of a vacuum pump ( 29 ), with a fifth globe valve ( 28 ) set between the vacuum pump ( 29 ) and the equilibrium still ( 25 ), and a third globe valve ( 16 ) set between the pressure-resistant gas chamber ( 15 ) and the equilibrium still ( 25 ).

7. The experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , wherein the data acquisition device ( 31 ) is connected to a controller ( 32 ).

8. A method using the experimental device for solubility determination of methane in oil-based drilling fluid according to claim 1 , comprising the following steps:
Step 1: Calibrate and verify the experimental device and pipe;
Step 2: Clean the equilibrium still ( 25 ), turn on the vacuum system ( 30 ) to vacuum, and test the air tightness of the experimental device;
Step 3: Heat the pressure-resistant gas chamber ( 15 ) and the equilibrium still ( 25 ) to the target temperature, turn on the vacuum system ( 30 ) for vacuuming, and inject the required drilling fluid into the dissolution equilibrium chamber in the equilibrium still ( 25 ) through the feed funnel ( 21 );
Step 4: Fill a certain amount of methane into the pressure-resistant gas chamber ( 15 ), heat the pressure-resistant gas chamber ( 15 ) to the target temperature, and obtain the temperature T 1 and pressure P 1 of the methane in the pressure-resistant gas chamber ( 15 ) after the pressure is stabilized;
Step 5: Inject methane from the pressure-resistant gas chamber ( 15 ) into the dissolution equilibrium chamber of the equilibrium still ( 25 ) until it reaches the set pressure, and obtain the temperature T 2 and pressure P 2 as the gas is released from the pressure-resistant gas chamber ( 15 ) after the pressure is stabilized;
Step 6: Adjust the constant-temperature oil bath heating oven ( 26 ) to reach the required temperature, and observe the pressure change in the dissolution equilibrium chamber in real time; If the pressure decreases, inject hydraulic oil into the hydraulic oil chamber ( 27 ) through the high-pressure metering pump ( 23 ) until reaching the set pressure, and record T 3 and P 3 in the equilibrium still ( 25 ) after the pressure is stabilized;
Step 7: Calculate the solubility of methane in oil-based drilling fluid based on the measured parameters.

9. The method for solubility determination of methane in oil-based drilling fluid according to claim 8 , wherein the solubility R S of methane in oil-based drilling fluid is calculated as follows:

n
=

Δ
⁢

n
g

-

n

g
⁢
3

=

(

n

g
⁢
1

-

n

g
⁢
2

)

-

n

g
⁢
3

Where, n is the mole fraction of methane dissolved in the oil-based drilling fluid; n g3 is the mole number of methane in the equilibrium still ( 25 ) after the dissolution equilibrium is reached; Δn g is the mole number of methane released from the pressure-resistant gas chamber ( 15 ) into the equilibrium still ( 25 ); n g1 is the mole number of methane in the pressure-resistant gas chamber ( 15 ) before it is released into the equilibrium still ( 25 ); n g2 is the mole number of methane in the pressure-resistant gas chamber ( 15 ) after it is released into the equilibrium still ( 25 );
The solubility R S is:

Assignees

• Univ Southwest Petroleum

Inventors

• Zhang Jie
• Sun Xuefeng
• Xue Qiulai
• Li Cuinan
• Wei Qiang
• Li Zhilin
• Duan Mubai
• He Xianjie

Classifications

• G01N33/2823

  Raw oil, drilling fluid or polyphasic mixtures · CPC title

• G01N13/00 Primary

  Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects (scanning-probe techniques or apparatus G01Q) · CPC title

• G01N33/2841 Primary

  Gas in oils, e.g. hydrogen in insulating oils · CPC title

• G01N33/0047 Primary

  Organic compounds · CPC title