System and process for reducing the flowing bottom hole pressure in a natural gas well

• US 6,315,048 B1
• Filed: 09/17/1999
• Issued: 11/13/2001
• Est. Priority Date: 09/17/1999
• Status: Expired due to Fees

• Current Assignee: T-RAD Enterprises, LLC
• Original Assignee: T-RAD Enterprises, LLC
• Inventors: Etzkorn, Timothy E.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): GAY, JENNIFER HAWKINS
• Application Number:
  US09/398,730
• Time in Patent Office: 788 Days
• Field of Search: 166/369, 166/370, 166/267, 952/43, 952/53, 952/54, 961/82, 961/83, 961/84, 962/07, 962/15
• US Class Current: 166/370
• CPC Class Codes: E21B 43/121 Lifting well fluids monitoring of down-hole pump systems E21B47/008

Abstract

A system and process for reducing the flowing bottom-hole pressure in a natural gas well has a first discrete fluid flow path extending from the surface well head through a valve to an inlet of a separator, the valve being actuable between a closed condition and an open condition, and a second discrete gas flow path extending from an outlet of the separator to an inlet of a compressor, the compressor maintaining a near or below zero PSIG pressure at the separator inlet. When the valve is in the closed condition, positive pressure builds on the well head side of the valve and, when the valve is in the open condition, the near or below zero PSIG pressure of the separator is applied to the well head. In applications for receiving a fluid column of gas and liquid loading a plunger in the production line of a natural gas well, when the negative pressure is applied to the well head, the fluid column is transferred along the fluid flow path into the separator and the gas is transferred along the gas flow path from the separator to the compressor.

Claims

1. For use in increasing a downhole to well head pressure differential of a natural gas well, a process comprising the steps of:

providing a discrete fluid flow path from a well head end of the well through a valve to an inlet of a separator;

providing a discrete gas flow path from an outlet of the separator to an inlet of a compressor;

operating the compressor to maintain near zero or below PSIG pressure at the separator inlet;

opening the valve to reduce the pressure at the well head.

2. The process of claim 1 said operating step comprising the substeps of:

sensing the compressor inlet pressure; and

varying at least one of;

(a) the rpm of the compressor prime mover;

(b) the external loading on the compressor; and

(c) the gear ratio between the prime mover and the compressor.

3. For use in removing a fluid column of liquid and gas loading a plunger in a production line of a gas well having a positive downhole pressure, a process comprising the steps of:

providing a discrete fluid flow path from a well head end of the production line through a valve to an inlet of a separator;

providing a discrete gas flow path from an outlet of the separator to an inlet of a compressor;

operating the compressor to maintain near zero or below PSIG pressure at the separator inlet;

opening the valve to allow the plunger to rise in the production line and convey the fluid column along the fluid flow path into the separator; and

continuing to operate the compressor to maintain a near or below zero PSIG pressure at the separator inlet to convey the gas along the gas flow path from the separator to the compressor.

4. For use in removing a fluid column of liquid and gas loading a plunger in a production line of a gas well having a positive downhole pressure, a process comprising the steps of:

providing a discrete fluid flow path from a well head end of the production line through a valve to an inlet of a separator;

providing a discrete gas flow path from an outlet of the separator to an inlet of a compressor;

operating the compressor to maintain a near or below zero PSIG pressure at the separator inlet;

closing the valve to build positive pressure on a well head side of the valve to resist upward movement of the plunger;

opening the valve to allow the plunger to rise in the production line and vent the fluid column along the fluid flow path into the separator; and

continuing to operate the compressor to maintain a near or below zero PSIG pressure at the separator inlet to convey the gas along the gas flow path from the separator to the compressor.

5. A system for increasing a differential between downhole and well head pressure in a natural gas well comprising:

a separator;

a discrete fluid flow path extending from a well head of the natural gas well through a valve to an inlet of said separator, said valve being actuable between a closed condition and an open condition;

a compressor;

a discrete gas flow path from an outlet of said separator to an inlet of said compressor;

said compressor maintaining a near or below zero PSIG pressure at said separator inlet,

whereby, when said valve is in said closed condition, positive pressure builds on a well head side of said valve and, when said valve is in said open condition, the near or below zero PSIG pressure of said separator is applied to the well head.

6. A system according to claim 5, said compressor having at least one of:

a variable speed prime mover;

a variable internal loading; and

a variable gear ratio between said prime mover and said compressor.

7. A system for removing a fluid column of liquid and gas loading a plunger in a production line of a gas well having a positive downhole pressure comprising:

a separator;

a discrete fluid flow path extending from a well head end of the production line through a valve to an inlet of said separator, said valve being actuable between a closed condition and an open condition;

a compressor;

a discrete gas flow path from an outlet of said separator to an inlet of said compressor;

said compressor maintaining a near or below zero PSIG pressure at said separator inlet,

whereby, when said valve is in said closed condition, positive pressure builds on a well head side of said valve opposing upward movement of the plunger and, when said valve is in said open condition, the plunger rises in the production line and the fluid column is transferred along said fluid flow path into said separator and the gas is transferred along said gas flow path from said separator to said compressor.

8. A system according to claim 7, said separator having a gravity discharge for exhausting the liquid therefrom.