US3817039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of filling subterranean voids with a particulate material
Assignee: Dow Chemical Co
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Filing: 1970-11-04
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Granted: 1974-06-18
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Expires: 1990-11-04
Abstract
Abstract A method is provided for backfilling a subterranean void, e.g. a mined out cavity such as a tunnel, etc. An aqueous suspension of solid particles (fill material) is injected through a conduit which connects the void with a suitable work surface (said conduit and void consisting of a closed pressurized system during injection) and into the void at a certain critical minimum rate.
Inventors
- 👤 J Stewart
- 👤 M Heslep
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:54
CPC Classifications
E; E21; E21F; E21F15/00; E21F15/08; E21C; E21C41/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
193 words
In the method of emplacing a layer of solid particles in a subterranean void wherein the layer occupies at least a major portion of the height of said void, comprising injecting a mixture of a carrier liquid and particulate solids through a conduit connecting a work surface and said void, the improvement which comprises: a. providing a closed system between injection equipment for said mixture, said conduit and said void; b. providing a suspension of said carrier liquid and said solids; and c. injecting said suspension into said void through said conduit at an injection rate which is sufficiently low such that initially upon entrance into said void from said conduit the velocity of the suspension is below its minimum linear velocity and at least a portion of said solid particles are deposited to form a mound which decreases the cross-sectional area of said void, and sufficiently high to propel the suspension over said mound at a velocity at least equal to its minimum linear velocity to carry particles over said mound whereby they are deposited to increase the length and height thereof, to form a layer of solid particles in said void.
Claim 2
Dependent Claim
193 words
In the method of emplacing a layer of solid particles in a subterranean void wherein the layer occupies at least a major portion of the height of said void, comprising injecting a mixture of a carrier liquid and particulate solids through a conduit connecting a work surface and said void, the improvement which comprises: a. providing a closed system between injection equipment for said mixture, said conduit and said void; b. providing a suspension of said carrier liquid and said solids; and c. injecting said suspension into said void through said conduit at an injection rate which is sufficiently low such that initially upon entrance into said void from said conduit the velocity of the suspension is below its minimum linear velocity and at least a portion of said solid particles are deposited to form a mound which decreases the cross-sectional area of said void, and sufficiently high to propel the suspension over said mound at a velocity at least equal to its minimum linear velocity to carry particles over said mound whereby they are deposited to increase the length and height thereof, to form a layer of solid particles in said void.
Claim 3
Dependent Claim
22 words
The improved method as defined in claim 1 wherein the height of the void is substantially completely filled with said particulate solids.
Claim 4
Dependent Claim
23 words
The improved method as defined in claim 1 wherein said conduit comprises a substantially vertical borehole connecting the void with a work surface.
Claim 5
Dependent Claim
112 words
The improved method as defined in claim 3 wherein the suspension is injected through the borehole at a minimum rate calculated by the formula V Xd pi Dv wherein V is the rate of injection in cubic feet per minute, X is a number of 3 or greater, d is the diameter in feet of the largest solid particles in said suspension, D is the diameter of the base of a cone formed by said particles in said carrier liquid when motionless, said cone having a height equal to the height to which said void is to be filled with said particles, and v is the minimum linear velocity of said suspension.
Claim 6
Dependent Claim
33 words
The improved method as defined in claim 4 wherein the carrier liquid is an aqueous based liquid and said solid particles range in size from about minus 3 to about plus 300 mesh.
Claim 7
Dependent Claim
29 words
The improved method as defined in claim 4 wherein said suspension comprises an aqueous carrier liquid containing said solid particles in a weight ratio of up to about 1:1.
Claim 8
Dependent Claim
33 words
The improved method as defined in claim 6 wherein the suspension comprises an aqueous carrier liquid and sand wherein said sand ranges in size from about minus 3 to about plus 300 mesh.
Claim 9
Dependent Claim
47 words
The improved method as defined in claim 3 wherein the suspension comprises an aqueous carrier liquid and a particulate solid ranging in size from about minus 3 to about plus 300 mesh and said weight ratio of said solids to said liquid ranges up to about 1:1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |