Subsidence control
AssigneeThe Dow Chemical Company
InventorsRobert E. Hurst, Charles L. Lunsford
Life of this patent
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Abstract
A method is provided for filling a subterranean void, e.g. a mined out cavity such as a tunnel. An aqueous suspension of solid particles the mass of which when at rest has a permeability of about 40 darcies, preferably less than 20 darcies, is injected into the void to effect complete filling.
Claims4
In a method of filling a subterranean void by injecting under pressure a carrier liquid, in which solid particles are suspended said particles consisting of a material which in a deposited form is permeable to the flow of said carrier liquid, into said void to form a deposit of solid particles within said void, the improvement which comprises:
- emplacing a filtercake consisting of a second layer of solids which is substantially impermeable to said carrier liquid on the exposed surface of the deposit then present to render said surface less permeable to said carrier liquid and then continuing said injection of said suspension of solid particles thereby to extend the deposit of said particles through said void.
Dependencies are inferred from the claim text.