US5018576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for in situ decontamination of subsurface soil and groundwater
Assignee: University of California
•
Filing: 1989-08-16
•
Granted: 1991-05-28
•
Expires: 2009-08-16
Abstract
Abstract A method is provided for in situ decontamination of contaminated subsurface area by injection of steam into injection wells and withdrawing liquids and vapors from extraction wells under subatmospheric pressure whereby steam is passed through the contaminated area in an essentially horizontal direction. After a substantial portion of the contamination has been removed in this manner, the injection of steam is ceased, but the extraction at subatmospheric pressure is continued, to volatilize and remove the residual water and contaminants trapped in the pores of the soil. The steam injection may be periodically resumed to reheat the area and to replenish the water in the pores.
Inventors
- 👤 Kent S. Udell
- 👤 Nicholas Sitar
- 👤 James R. Hunt
- 👤 Lloyd D. Stewart, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:29
CPC Classifications
E; E02; E02D; E02D3/00; E02D3/11; B; B09; B09C; B09C1/00; B09C1/005; B09C1/02; B09C1/06; E21; E21B; E21B43/00; E21B43/16; E21B43/24; B09C2101/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
A process for in situ decontamination of a contaminated subsurface area containing volatile contaminants, nonvolatile aqueous soluble contaminants and nonvolatile nonaqueous volatile contaminants, comprising the steps of: (a) constructing an injection well system comprising a plurality of injection wells proximate to the periphery of and/or located within said contaminated area; (b) constructing at least one extraction well disposed within said contaminated area and spaced apart from said injection wells; (c) concurrently injecting steam into said injection well system and applying subatmospheric pressure to said extraction well whereby steam is drawn in a substantially horizontal direction through said contaminated subsurface area to thereby heat said area, volatilize, and extract a substantial amount of said volatile contaminants from said area; whereby water, nonvolatile and volatile contaminants are withdrawn through said extraction well; (d) ceasing injection of said steam into said injection well system and continuing the application of subatmospheric pressure at said extraction well to withdraw residual steam and gases, and residual liquids from said subsurface area, which gases and steam are volatilized by the residual heat in said subsurface area.
Claim 2
Dependent Claim
179 words
A process for in situ decontamination of a contaminated subsurface area containing volatile contaminants, nonvolatile aqueous soluble contaminants and nonvolatile nonaqueous volatile contaminants, comprising the steps of: (a) constructing an injection well system comprising a plurality of injection wells proximate to the periphery of and/or located within said contaminated area; (b) constructing at least one extraction well disposed within said contaminated area and spaced apart from said injection wells; (c) concurrently injecting steam into said injection well system and applying subatmospheric pressure to said extraction well whereby steam is drawn in a substantially horizontal direction through said contaminated subsurface area to thereby heat said area, volatilize, and extract a substantial amount of said volatile contaminants from said area; whereby water, nonvolatile and volatile contaminants are withdrawn through said extraction well; (d) ceasing injection of said steam into said injection well system and continuing the application of subatmospheric pressure at said extraction well to withdraw residual steam and gases, and residual liquids from said subsurface area, which gases and steam are volatilized by the residual heat in said subsurface area.
Claim 3
Dependent Claim
29 words
A process according to claim 1 wherein said step (c) is conducted for a period of time sufficient to remove a substantial amount of said contaminants from said area.
Claim 4
Dependent Claim
26 words
A method according to claim 1 further comprising the step (e) of introducing to said area biota and nutrients therefor for biodegradation of any residual contamination.
Claim 5
Dependent Claim
13 words
A process according to claim 1 comprising repeating said steps (c) and (d).
Claim 6
Dependent Claim
170 words
A process for in situ decontamination of a contaminated subsurface area containing volatile contaminants, nonvolatile aqueous soluble contaminants and nonvolatile nonaqueous volatile contaminants, comprising the steps of: (a) concurrently injecting steam into an injection well system, said system comprising a plurality of injection wells proximate to the periphery of and/or located within said contaminated area, and applying subatmospheric pressure to at least one extraction well disposed within said contaminated area and spaced apart from said injection wells, whereby steam is drawn in a substantially horizontal direction through said contaminated subsurface area to thereby heat said area, volatilize, and extract a substantial amount of said volatile contaminants from said area; whereby water, nonvolatile and volatile contaminants are withdrawn through said extraction well; (b) ceasing injection of said steam into said injection well system and continuing the application of subatmospheric pressure at said extraction well to withdraw residual steam and gases, and residual liquids from said subsurface area, which gases and steam are volatilized by the residual heat in said subsurface area.
Claim 7
Dependent Claim
170 words
A process for in situ decontamination of a contaminated subsurface area containing volatile contaminants, nonvolatile aqueous soluble contaminants and nonvolatile nonaqueous volatile contaminants, comprising the steps of: (a) concurrently injecting steam into an injection well system, said system comprising a plurality of injection wells proximate to the periphery of and/or located within said contaminated area, and applying subatmospheric pressure to at least one extraction well disposed within said contaminated area and spaced apart from said injection wells, whereby steam is drawn in a substantially horizontal direction through said contaminated subsurface area to thereby heat said area, volatilize, and extract a substantial amount of said volatile contaminants from said area; whereby water, nonvolatile and volatile contaminants are withdrawn through said extraction well; (b) ceasing injection of said steam into said injection well system and continuing the application of subatmospheric pressure at said extraction well to withdraw residual steam and gases, and residual liquids from said subsurface area, which gases and steam are volatilized by the residual heat in said subsurface area.
Claim 8
Dependent Claim
29 words
A process according to claim 5 wherein said step (b) is conducted for a period of time sufficient to remove a substantial amount of said contaminants from said area.
Claim 9
Dependent Claim
26 words
A process according to claim 5 further comprising the step (c) of introducing to said area biota and nutrients therefor for biodegradation of any residual contamination.
Claim 10
Dependent Claim
13 words
A process according to claim 5 comprising repeating said steps (a) and (b).
References Cited (Backward Citations)
US3796262A
Cited
US4288174A
Cited
US4323122A
Cited
US4401569A
Cited
US4597443A
Cited
US4660639A
Cited
US4593760A
Cited
US4593760B1
Cited
US4526692A
Cited
US4608163A
Cited
US4761225A
Cited
US4730672A
Cited
US4838079A
Cited
US4765902A
Cited
US4842448A
Cited
US4832122A
Cited
US4848460A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-27 | 1994-11-26 | 1995-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-27 | 1998-11-26 | 1999-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-27 | 2002-11-26 | 2003-05-28 | $7700.00 | Window Closed / Lapsed |