Abstract: A surface drilling apparatus for drilling large diameter holes in soft to medium-hard earth formations includes a cylindrical casing defined by a stationary upper section and a lower section rotatable relative to the upper section; a plurality of circular rows of cutting discs rotatably mounted on the base of the lower section for cutting material beneath the apparatus; a transfer pipe in the center of the base of the lower section for receiving cut material from the cutting discs and feeding the cut material upwardly through a discharge pipe for carrying the material upwardly to the surface; and an annular, upwardly inclined slot in the discharge pipe at the top of the upper section through which air is fed under pressure into the discharge pipe to induce the cut material upwardly from the transfer pipe and blow the material upwardly.

Abstract: A drilling rig comprising a plurality of pipes connected in a row, with a drill at the lower end; the rotation transmitting bar or Kelly bar at the top end of the drilling rig must be periodically disconnected so as to install a new pipe section; the invention comprises a valve to seal the upper rotating or Kelly bar when it is disconnected so as to keep the sludge pump primed; the valve comprising a collapsible diaphragm which is forced shut by pressurized fluid to seal the rotating or Kelly bar; and an air escape valve communicating into the row of pipes beneath the sealing valve for effecting removal of air trapped beneath the rotating or Kelly bar valve.

Abstract: A method for removing material from directional wells using centralized tubing to circulate foam in the well at a velocity in excess of 30 feet per minute.

Abstract: Lost circulation in a well occurring during drilling is reduced by aeration of clay-free, non-thixotropic, brine wellbore fluids comprising hydroxyalkyl cellulose and preferably magnesia as a stabilizer. The gas is easily and completely removed from the foam returned to surface with only a conventional degassing and gas busting equipment normally found in a solids removal system. The advantages of the clay-free, non-thixotropic, drilling fluids as known are preserved and the system allows rapid change from aerated to non-aerated fluid as required.

Abstract: A method and means for using nitrogen exhaust gases or gaseous mixtures of combustible products for reduction of oxygen in drilling fluids during the drilling of well bores and which comprises utilizing nitrogen from normally waste exhaust gases or the like, injecting the nitrogen and other gases present into the usual drilling muds for replacing the oxygen contents of the drilling muds with the nitrogen gas, whereby corrosive action of the drilling muds is greatly reduced or substantially eliminated.

Abstract: A method for conducting foam drilling and workover oprations in a bore hole penetrating a subterranean reservoir employing an aqueous solution of a biodegradable foaming agent composition containing about 0.1 to 1 part by weight of an N-fatty ethyl sulfate salt having the formula: ##STR1## wherein R is a straight chain alkyl radical having from 10 to 16 carbon atoms and M is an alkali metal or ammonium cation, per part per weight of a fatty acid salt having the formula: ##STR2## wherein R.sub.1 is a straight chain alkyl radical having from 9 to 15 carbon atoms and M.sub.1 is an alkali metal or ammonium cation. A particularly preferred foaming agent composition contains sodium 2-(N-lauryl) ethyl sulfate and sodium laurate.

Abstract: A method for conducting foam drilling and workover operations in a bore hole penetrating a subterranean reservoir employing an aqueous solution of a biodegradable foaming agent composition containing about 0.3 to 3 parts by weight of an N-fatty ethyl sulfonic acid salt having the formula: ##STR1## per part by weight of an N-fatty propionic acid salt having the formula: ##STR2## wherein R and R.sub.1 are straight chain alkyl radicals having from 10 to 16 carbon atoms, and M and M.sub.1 are alkali metal or ammonium cations. A particularly preferred foaming agent composition contains sodium 2-(N-lauryl) ethyl sulfonic acid and sodium 2-(N-lauryl) propionic acid.

Abstract: Apparatus for concentric multi-string drilling with reverse air vacuum for the entrainment of chips and dust, selectively controlled through a plurality of annuli defined by the multiplicity of drill strings adapted to individually and/or cooperatively operate drill bits and reamers and the like to bore geological formations as required.

Abstract: An improved offshore drilling method and apparatus are disclosed which are useful in preventing formation fracture caused by excessive hydrostatic pressure in a drilling riser. Gas is injected into the riser to provide the lift necessary to return the drilling fluid to the surface and to reduce the density of the drilling fluid. The rate of gas injection overlifts the drilling fluid to the extent that the pressure of the fluid is reduced to less than that of the seawater surrounding the riser. Seawater is permitted to flow into the lower end of the riser in response to the differential pressure between the drilling fluid and seawater so that the pressures of the drilling fluid and the seawater approximately equalize.

Abstract: A composition and method for drilling wells through subterranean strata containing high temperature aqueous fluids using a gas-containing aqueous drilling fluid containing an alkaline material to raise the pH of the drilling fluid to provide corrosion protection in the liquid phase and a volatile water-soluble nitrogen-containing compound to provide corrosion protection in the gaseous phase.

Abstract: Composition and method for drilling a well into a high temperature subterranean reservoir, such as one containing a geothermal fluid, wherein there is used an aqueous foam drilling fluid containing (1) water, (2) gas, (3) a foaming agent, (4) an erosion and corrosion inhibitor, (5) a water-soluble or water-dispersible carboxyalkyl cellulose ether or polyalkylene oxide polymer which both controls the fluid loss of the foam and toughens it, and, optionally, (6) a bit lubricant and/or (7) an anti-torqueing agent.

Abstract: In a method of making holes of selective external configuration in a rock or earth formation, two or more rotatable drills provided with drill crowns are driven into the ground. The drill crowns are so arranged that they will touch each other or are radially spaced a small distance from each other and are substantially on the same level. The drill crowns are simultaneously axially displaced while they are rotated each about its own axis only. The drill crowns sit on drill rods provided with guide means such as tubes which are driven into the ground substantially simultaneously as the drill crowns. The guide means may be connected together to form a single common guide structure. When drilling two or more holes situated adjacent one or more previously drilled holes, a guide means having spacer means is inserted into a previously drilled hole, said spacer means guiding the drill for the further holes relative to the previously drilled hole by engagement with the residual walls of the drilled hole.

Abstract: A process is disclosed for in-situ mining of copper from a subterranean ore body characterized, at least in part, by the presence of a sulfidic ore and by natural, microscopic fracture openings. The process comprises forcing a stable, two-phase lixiviant comprising an aqueous phase, a multiplicity of gaseous, oxygen-containing bubbles having a size sufficient to pass through the natural fracture openings in the ore body, and a surfactant for enhancing the formation of the bubbles and for minimizing bubble coalescence through the ore body to leach copper.The aqueous and gaseous phases of the lixiviant are mixed at the surface and injected into the leaching interval through an injection hole, or preferably, are mixed in a subterranean sparger within the hole above the leaching interval. The pregnant liquor is recovered through one or more production holes and, after the copper is recovered, the lixiviant may be reconstituted and recirculated.

Abstract: A composition and method for drilling a well into a subterranean reservoir containing a high temperature aqueous liquid which composition contains as a scale inhibitor (i) a water-soluble substituted iminodi(methylene phosphonic acid) compound having a carbon-to-phosphorus bond or a water-soluble salt thereof, (ii) a dicarboxylic acid, (iii) a lower alkyl ester or hydroxy derivative of a dicarboxylic acid, (iv) hexamethylenetetramine, (v) thiourea, or (vi) the amide reaction product of a polycarboxylic acid and an aliphatic amine, an aliphatic hydroxyl amine, or a heterocyclic nitrogen-containing compound.

Abstract: A composition and method for drilling a well into a subterranean formation containing a geothermal fluid utilizing a gas-containing aqueous drilling fluid containing both lignite and a salt of a high molecular weight acrylic polymer.

Abstract: A method of conducting foam drilling and workover operations in a bore hole penetrating a subterranean formation, particularly a high-temperature formation such as a geothermal formation, employing an aqueous solution of a N-acyl-N-methyltaurate foaming agent having the formula: ##STR1## wherein R is a straight chain alkyl group having from 9 to 15 carbon atoms; and M is an alkali metal or ammonium cation, with sodium being preferred. A particularly preferred foaming agent is sodium N-palmitoyl-N-methyltaurate.

Abstract: Organic disulfonic acids are produced by heating a sulfonate monomer at a temperature above 110.degree.C. in the substantial absence of water. Olefin sulfonation product mixtures, hydroxyalkane sulfonic acids, alkane sultones, alkene sulfonic acids and mixtures thereof are oligomerized under these conditions.

Abstract: Organic disulfonic acids are produced by heating a sulfonate monomer at a temperature above 110.degree.C. in the substantial absence of water. Olefin sulfonation product mixtures, hydroxyalkane sulfonic acids, alkane sultones, alkene sulfonic acids and mixtures thereof are oligomerized under these conditions.