Method for developing water wells

Claim 1

The method of removing particulate matter from the bottom of a drilled water well having a casing open at its top, which comprises the steps of (a) lowering a pair of tubes one within the other into said casing so that their lower ends extend below the level of the water in said well, with the outer tube extending below the inner tube to a site near the bottom of said well, to define a primary upward discharge path, between said outer tube and said inner tube, and a secondary upward discharge path, between said outer tube and said casing; (b) supplying air to the top of said inner tube at such a pressure as to cause a primary discharge of fluid upward through said primary discharge path by air-lift operation; (c) and intermittently first closing said primary discharge path near the top of said outer tube--to interrupt said primary discharge and compel said air to cause a secondary discharge of water downward through said outer tube, and then upward at high velocity through said second discharge path, to entrain said particulate matter--and afterwards suddenly reopening said primary discharge path to interrupt said secondary discharge, enabling rapid gravitational return of water in said secondary discharge path and reestablishing said primary discharge.

Claim 2

The method of removing particulate matter from the bottom of a drilled water well having a casing open at its top, which comprises the steps of (a) lowering a pair of tubes one within the other into said casing so that their lower ends extend below the level of the water in said well, with the outer tube extending below the inner tube to a site near the bottom of said well, to define a primary upward discharge path, between said outer tube and said inner tube, and a secondary upward discharge path, between said outer tube and said casing; (b) supplying air to the top of said inner tube at such a pressure as to cause a primary discharge of fluid upward through said primary discharge path by air-lift operation; (c) and intermittently first closing said primary discharge path near the top of said outer tube--to interrupt said primary discharge and compel said air to cause a secondary discharge of water downward through said outer tube, and then upward at high velocity through said second discharge path, to entrain said particulate matter--and afterwards suddenly reopening said primary discharge path to interrupt said secondary discharge, enabling rapid gravitational return of water in said secondary discharge path and reestablishing said primary discharge.