Sand stabilization in selected formations

Claim 1

The method of claim 1 further characterized in that the ratio of hydroxyl groups to Al atoms is from 2.0 to 2.4.

Claim 6

A method of stabilizing sand in clay-containing formations penetrated by a well comprising obtaining at least two samples of a formation, treating one of said samples with an aqueous hydroxy-aluminum solution, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7, preparing the treated sample and the untreated sample for comparative flow tests, conducting comparative flow tests on said samples to determine if the treated sample is significantly sand stabilized compared to the untreated sample and, if such is the case, injecting a hydroxy-aluminum solution down a well penetrating said formation and contacting the formation with said solution to stabilize sand in said formation, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7.

Claim 12

A method of stabilizing sand in clay-containing formations penetrated by a well comprising selecting a formation containing sand interspaced with clay mineral and X-ray amorphous material, the said clay mineral and amorphous material being collectively present in an amount of at least 5 weight percent, injecting an aqueous hydroxy-aluminum solution down said well and contacting said formation with said solution to stabilize sand in said formation, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7.

Claim 19

A method of stabilizing sand in clay-containing formations penetrated by a well comprising obtaining a sample of a formation containing sand and clay mineral, determining the cation exchange capacity of the clay mineral in said sample, when the said cation exchange capacity is greater than about 0.6 Meq/100 gm injecting an aqueous hydroxy-aluminum solution down a well and contacting said formation with said solution to stabilize sand in said formation, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7.

Claim 26

A method of stabilizing sand in clay containing formations penetrated by a well comprising selecting a formation containing sand and clay mineral which formation is susceptible to sand stabilization on reaction with a hydroxy-aluminum solution, acidizing said formation by injecting acid down a well and into said formation, injecting a buffer liquid down said well after said acid, injecting an aqueous hydroxy-aluminum solution down said well after said buffer liquid and contacting said formation with said solution to stabilize sand in said formation, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7.

Claim 32

A method of stabilizing sand in a formation containing sand and clay mineral which formation is susceptible to sand stabilization on reaction with a hydroxy-aluminum solution comprising contacting said formation with an aqueous hydroxy-aluminum solution to stabilize sand in said formation, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7.

Claim 38

A method of stabilizing sand in a formation penetrated by a well and containing sand and clay mineral which formation is susceptible to sand stabilization on reaction with a hydroxy-aluminum solution comprising injecting an aqueous hydroxy-aluminum solution down a well and contacting said formation with said solution to stabilize sand in said formation, the ratio of the hydroxyl groups to Al atoms in said solution being in the range of from 1.5 to 2.7.