Gas assisted chemical injection system

Patent metadata

Field	Value
Publication number	US-10671099-B2
Application number	US-201815866055-A
Country	US
Kind code	B2
Filing date	Jan 9, 2018
Priority date	Jan 9, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A system and method for dispensing an injection material to an injection point. The injection material is stored in a tank and disposed to parallel piped vessels. An orifice is disposed in piping connected to discharge ends of the vessels, and has an opening with a designated cross sectional area. A high pressure fluid drives the injection material to the injection point; the pressure of the high pressure fluid is regulated with a pressure control valve. Valves in the inlet and discharge piping connected to the vessels are selectively opened and closed so that injection material flows to and from the vessels. Vessels vent to a recycle/recovery system to reduce vessel pressure enabling refilling with injection material. Valves in the pressurizing and depressurizing lines are selectively opened and closed to depressurize and refill the vessels to have continuous chemical injection to the injection location.

First claim

What is claimed is:

1. A method of dispensing an injection material comprising:
a. directing injection material into a first vessel;
b. pressurizing the first vessel to a specified pressure;
c. discharging a designated amount of the injection material from the first vessel and through a discharge line coupled with the first vessel;
d. controlling a rate of the injection material being discharged from the first vessel by introducing a pressure drop in the discharge line;
e. directing the injection material from the first vessel to an injection location;
f. depressurizing the first vessel; and
g. repeating steps (a)-(f) using a second vessel.

2. The method of claim 1 , further comprising regulating a flow of the injection material directed from the first vessel with a planar orifice having an opening with a designated cross sectional area, and that is disposed in the discharge line.

3. The method of claim 1 , wherein pressurizing the first vessel comprises providing fluid to the first vessel through an injection pressure inlet line, and wherein the injection pressure inlet line is in communication with the discharge line through a single path that extends through the first vessel.

4. The method of claim 3 , wherein pressure in the injection pressure inlet line is greater than a pressure in the discharge line.

5. The method of claim 4 , where an inlet piping circuit provides fluid communication between a tank in which injection material is stored and the first and second vessels, and a discharge circuit provides fluid communication between the first and second vessels and the injection location.

6. The method of claim 5 , where valves are provided in the inlet piping circuit and the discharge circuit that are selectively opened and closed to selectively direct injection material from and to the vessels.

7. The method of claim 6 , further comprising using a controller to direct command signals to actuators mounted to the valves for opening and closing the valves.

8. The method of claim 1 , further comprising venting pressurized fluid from one of the first or second vessels to a recycle/recovery system.

9. The method of claim 1 , wherein the injection material flows to the injection location continuously and uninterrupted, wherein the first vessel is pressurized with a pressure source that is at a fixed pressure, and wherein the injection location is at a fixed pressure.

10. The method of claim 1 , further comprising venting pressurized fluid between the first and second vessels.

11. A method of dispensing an injection material comprising:
a. directing injection material into a vessel;
b. directing pressurized fluid across a pressure control valve and to the vessel to pressurize the vessel to a specified pressure;
c. discharging a designated amount of the injection material from the vessel to an injection location; and
d. controlling the amount of injection material flowing from the vessel at the designated amount by flowing the injection material through an orifice having an opening with a particular cross sectional area in conjunction with maintaining a pressure of the pressurized fluid directed across the pressure control valve at the specified pressure.

12. The method of claim 11 , wherein the vessel comprises a first vessel, the method further comprising depressurizing the first vessel; and repeating steps (a)-(d) using a second vessel.

13. The method of claim 11 , further comprising estimating a rate that the injection material flows through the orifice with the following equation:

Q
=

(
C
)

*

(

A
o

)

=

2
⁢
Δ
⁢

⁢

p
/
ρ

1
-

(

Ao
A

)

2

;

where:
Q=flow rate of fluid flowing through orifice,
Δp=pressure drop across orifice,
ρ=density of the fluid flowing through the orifice,
A o =the cross sectional area of the opening in the orifice,
A=area of the pipe in which the orifice is disposed, and
C o =the flow coefficient across the orifice.

14. A system for dispensing injection material comprising:
a vessel that selectively contains injection material;
a pressure control valve having in inlet in communication with a pressure source, and an outlet in communication with the vessel having a varying pressure so that pressure in the vessel is at a designated value;
a piping circuit having ends connected to the vessel and to an injection location so that the vessel and injection location are in communication through the piping circuit;
an orifice in the piping circuit having an opening with a particular cross sectional area; and
a controller in signal communication with the pressure control valve and a flow-meter in the piping circuit that provides commands to the pressure control valve based on a comparison of a rate of flow of the injection material measured by the flowmeter and a designated rate of flow of the injection material.

15. The system of claim 14 , where the particular cross sectional area of the opening in the orifice is strategically sized, so that the rate of flow of injection material is substantially the same as the designated amount of injection material is metered to the injection location when pressure at the pressure control valve outlet is substantially at the designated value.

16. The system of claim 14 , where the vessel comprises a first vessel, and where the system comprises a second vessel.

17. The system of claim 16 , where the piping circuit further comprises inlet piping in communication with inlets formed in the first and second vessels and also in communication with a tank in which injection material is stored.

18. The system of claim 14 , further comprising a pressure discharge lead having an end attached to the vessel and that is in communication with a recycle/recovery system and a pressure inlet lead having an end connected to the vessel and that is in communication with the pressure source, and wherein a portion of the pressure discharge lead and the pressure inlet lead share a common length of piping.

19. The system of claim 14 , where the injection location comprises a position that is selected from the group consi

Assignees

• Saudi Arabian Oil Co

Inventors

• Ansari Nisar Ahmad K
• Salu Samusideen Adewale
• Al-Zahrani Talal
• Soliman Mohamed

Classifications

• F04F1/06

  the fluid medium acting on the surface of the liquid to be pumped (F04F1/02 takes precedence) · CPC title

• B01J4/008

  Feed or outlet control devices · CPC title

• G05D7/0658 Primary

  the plurality of throttling means being arranged for the control of a single flow from a plurality of converging flows (G05D7/0652 takes precedence; ratio control G05D11/13) · CPC title

• F17C13/04

  Arrangement or mounting of valves (valves per se F16K {; snap-coupling of nipples F16L37/00}) · CPC title

• G05D11/132 Primary

  by controlling the flow of the individual components (G05D11/133 takes precedence) · CPC title