Non-cryogenic production of nitrogen for on-site injection in well clean out

• US 6,494,262 B1
• Filed: 08/18/2000
• Issued: 12/17/2002
• Est. Priority Date: 08/18/2000
• Status: Expired due to Term

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Weatherford/Lamb Incorporated (Weatherford International PLC)
• Inventors: Chitty, Gregory H.
• Primary Examiner(s): Neuder, William
• Assistant Examiner(s): BATES, ZAKIYA W
• Application Number:
  US09/642,447
• Time in Patent Office: 851 Days
• Field of Search: 166/270.1, 166/401, 166/311, 166/312, 166/309, 166/372, 166/301, 166/90.1, 166/75.12, 166/56, 175/71, 95/47, 951/38
• US Class Current: 166/311
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2257/104 Oxygen
• CPC Class Codes: B01D 2259/40052 Recycled product or process gas
• CPC Class Codes: B01D 2259/402 using two beds
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: B01D 53/053 with storage or buffer vessel
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: E21B 37/06 using chemical means for preventing or limiting , e.g. eliminating, the deposition of paraffins or like substances

Abstract

There is disclosed a method for cleaning out of a well in which a compressed inert gas, produced by the non-cryogenic separation of air is delivered to the region of the well where particulate matter has collected that inhibits the ability of the well to produce.

Claims

1. A method for cleaning out a well in which production is inhibited, comprising:

(a) removing at least a substantial portion of the oxygen contained within a feed stream of air at the site of said well to produce an inert rich gas and an oxygen enriched waste gas, wherein the inert rich gas is nitrogen rich gas, and wherein oxygen is removed by passing a feed stream of air through a membrane which preferentially separates nitrogen gas from the other gaseous components of air; and

(b) delivering the inert rich gas to the area of the well to be cleaned out, whereby material inhibiting the production of the well is relocated.

2. The method of claim 1, wherein the nitrogen rich gas contains at least 85 percent volume of nitrogen.

3. The method of claim 1, wherein the nitrogen rich gas contains at least 95 percent volume of nitrogen.

4. The method of claim 1, further comprising raising the pressure of the nitrogen rich gas to at least 1000 psig before delivering the nitrogen rich gas to the area of the well to be cleaned out.

5. The method of claim 1, wherein the pressure of the nitrogen rich gas is raised to about 1,000 to 2,000 psig.

6. The method of claim 1, wherein the inert rich gas is delivered with an additive.

7. The method of claim 6, wherein the additive is a surfactant.

8. The method of claim 7, wherein the inert rich gas is delivered with foam.

9. A method for cleaning out a well in which production is inhibited, comprising:

(a) removing at least a substantial portion of the oxygen contained within a feed stream of air at the site of said well to produce an inert rich gas and an oxygen enriched waste gas;

(b) varying the oxygen content of the inert rich gas; and

(c) delivering the inert rich gas to an area of the well to be cleaned out, whereby material inhibiting the production of the well is relocated.

10. A method for cleaning out a well in which production is inhibited, comprising:

(a) removing at least a substantial portion of the oxygen contained within a feed stream of air at the site of said well to produce an inert rich gas and an oxygen enriched waste gas, wherein the inert rich gas is nitrogen rich gas, and wherein oxygen is removed by passing a feed stream of air through a pressure swing adsorption unit containing an absorbent which preferentially adsorbs oxygen and other gases contained within the feed stream of air to form the nitrogen rich gas;

(b) raising the pressure of the nitrogen rich gas to about 1,000 to 2,000 psig; and

(c) delivering the inert rich gas to the area of the well to be cleaned out, whereby material inhibiting the production of the well is relocated.

11. A method for cleaning out a well in which production is inhibited, comprising:

(a) removing at least a substantial portion of the oxygen contained within a feed stream of air at the site of said well to produce an inert rich gas and an oxygen enriched waste gas; and

(b) delivering the inert rich gas in coiled tubing to an area of the well to be cleaned out, whereby the coiled tubing is delivered to an area inside of production tubing and the material inhibiting the production of the well is relocated, whereby the material is circulated towards the surface of the well through an annulus between the coiled tubing and the production tubing.

12. The method of claim 11, wherein the method includes the step of moving the lower end of the coiled tubing up and downwards in the production tubing in order to agitate the particulate matter.