Abstract: A method of controlling subterranean flow of contaminants draining from a zone of contaminant concentration, includes(a) determining the locus of flow of contaminants in a porous underground formation, and(b) injecting into the formation a substance that creates a barrier in the formation to said flow, to thereby block said flow.

Abstract: Apparatus for recovering metallic particles from a recovery hole formed in a sub-surface formation containing said particles, comprises(a) a barge,(b) a rotating cutter head supported by the barge for controlled bodily movement at the recovery hole and for cutting the formation adjacent said hole to form cuttings mixed with said particles,(c) hydraulic conduit means supported by the barge to deliver flushing water to the vicinity of the cutter in said recovery hole, thereby to produce a slurry of water, cuttings and metallic particles, and(d) a suction duct supported by the barge, and having an intake located to draw said slurry from the hole for subsequent processing to separate and recover the metallic particles.

Abstract: Apparatus for recovering metallic particles in a sub-surface formation includes first and second ducts that extend downwardly, the first duct discharging water in a pressurized stream to effect differential elevation of particles in a turbulant water zone. The second duct has an intake positioned for drawing water and particles into the second duct from that zone. A loose flexible connection interconnects the two ducts to accommodate second duct movement up and down and laterally relative to the first duct. Also provided is means to adjust the position of the second duct intake relative to the discharge of the first duct, and a carrier vehicle movable over terrain and water and suspending the two ducts.

Abstract: Well flow control apparatus includes a blow-out preventer or preventers removably installable in a well head. By-pass porting may be provided in the well head to by-pass the preventers; a shroud may be employed over the head to confine gases against leakage; and a special valve assembly may be provided to control production fluid flow.

Abstract: A well installation, such as casing, tubing, a line movable in the well, and surface equipment, consists of high strength, light weight, non-metallic material.