Patent US3650327A successfully refreshed from Google Patents.
US3650327A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal insulation of wells
Assignee: Shell USA Inc
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Filing: 1970-07-14
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Granted: 1972-03-21
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Expires: 1990-07-14
Abstract
Abstract A method for thermally insulating a well, such as a steam injection well or a well which produces oil through perma-frost formations, by filling an annular space between two strings of casing in the wells with heat insulating vermiculite slurry.
Inventors
- 👤 Floyd D Burnside
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:06
CPC Classifications
E; E21; E21B; E21B36/00; E21B33/00; E21B33/10; E21B36/003; Y; Y10; Y10S; Y10S166/00; Y10S166/901
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
136 words
A method for insulating a well through which a fluid passes between a sub-surface earth formation and the surface of the earth comprising the steps of: drilling a borehole from the surface at least to a point adjacent the bottom of a zone in which heat loss is desired to be minimized; extending into the borehole and substantially through said zone a first tubular casing of relatively large diameter; extending into the borehole and substantially through said zone a second concentric tubular casing of smaller diameter; pumping a nonsetting slurry comprising vermiculite suspended in a carrier liquid into the annular space between said first and second tubular casings; closing the annular space adjacent the bottom of said zone with a seal-off means; and drying the vermiculite by controlled application of heat to vaporize the carrier liquid.
Claim 2
Independent Claim
136 words
A method for insulating a well through which a fluid passes between a sub-surface earth formation and the surface of the earth comprising the steps of: drilling a borehole from the surface at least to a point adjacent the bottom of a zone in which heat loss is desired to be minimized; extending into the borehole and substantially through said zone a first tubular casing of relatively large diameter; extending into the borehole and substantially through said zone a second concentric tubular casing of smaller diameter; pumping a nonsetting slurry comprising vermiculite suspended in a carrier liquid into the annular space between said first and second tubular casings; closing the annular space adjacent the bottom of said zone with a seal-off means; and drying the vermiculite by controlled application of heat to vaporize the carrier liquid.
Claim 3
Dependent Claim
11 words
The methoD of claim 1 wherein said carrier liquid is water.
Claim 4
Independent Claim
108 words
A method for insulating a well through which hot fluid is injected into a sub-surface formation of interest comprising the steps of: extending a borehole to a point adjacent the top of said formation of interest; running a string of relatively large diameter casing into the borehole; extending the borehole into the formation of interest; running a second string of smaller diameter casing from the surface to a point adjacent the bottom of the borehole; mixing a nonsetting slurry comprising vermiculite and carrier liquid; placing said slurry in the annular space between the larger and smaller diameter casings; and cementing the smaller casing adjacent the formation of interest.
Claim 5
Independent Claim
108 words
A method for insulating a well through which hot fluid is injected into a sub-surface formation of interest comprising the steps of: extending a borehole to a point adjacent the top of said formation of interest; running a string of relatively large diameter casing into the borehole; extending the borehole into the formation of interest; running a second string of smaller diameter casing from the surface to a point adjacent the bottom of the borehole; mixing a nonsetting slurry comprising vermiculite and carrier liquid; placing said slurry in the annular space between the larger and smaller diameter casings; and cementing the smaller casing adjacent the formation of interest.
Claim 6
Dependent Claim
58 words
The method of claim 3 wherein the carrier liquid is water and wherein the method comprises the additional steps of: opening the borehole into fluid communication with the formation of interest; and injecting a hot fluid into the zone of interest at a controlled rate to dehydrate the vermiculite slurry without causing excessive steam pressure in the slurry.
Claim 7
Dependent Claim
61 words
The method of claim 3 including the step of fixing the top of said smaller diameter casing with a slip type packoff means capable of providing a substantially fluidtight seal off of the annular space between said larger and smaller diameter casing strings while simultaneously allowing said smaller diameter casing to move upwardly or downwardly relative to said larger diameter casing.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |