Abstract: A process of boring a tunnel using an earth-pressure balance shield boring tunnelling machine having a cutting head, an excavation chamber for soil removed by boring and conveying means for removal of said soil from the excavation chamber; wherein there is injected into a stratum being bored at the cutting head a foamed aqueous solution, characterized in that (a) the aqueous solution contains two essential components which are (i) a sulphate- or sulphonate-containing anionic susfactant, and (ii) &bgr;-naphthalene sulphonate-formaldehyde condensate; and in that (b) there is applied to the soil removed by boring in at least one of the excavation chamber and the conveyor a second aqueous solution containing essentially a high molecular weight polyethylene oxide and optionally a sulphate- or sulphonate-containing anionic surfactant. The process allows easy removal of soil from the cutting head to the excavation chamber and from the excavation chamber out of the machine.

Abstract: A method of drilling sub-sea oil and gas production wells in which a liquid hydrocarbon substance, such as a natural gas liquid, is injected into the drilling mud supplied to the well in order to reduce the mud density. The method of the present invention enables reduction and control of the hydraulic pressure of the drilling mud while drilling production wells in deep water, thereby to require fewer casing runs which eventually yields better oil productivity.

Abstract: A method and apparatus for controlling the operation of an internal combustion engine to reduce the presence of free oxygen in the exhaust gas of the engine. The method and apparatus provides for the internal combustion engine to be operated with a fuel-to-air ratio in excess of the stoichiometric ratio such that the exhaust gas from the internal combustion engine is devoid or substantially devoid of all free oxygen and excess unburned hydrocarbon fuel is expelled with the exhaust gas from the engine.

Abstract: Improved methods of generating gas in and foaming aqueous well fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining with an alkaline aqueous well fluid one or more gas generating chemicals and a mixture of foaming and foaming stabilizing surfactants so that the gas generating chemical or chemicals react with the alkaline aqueous well fluid and gas and foam are formed in the well fluid while it is being pumped, and then pumping the well fluid into the subterranean zone.

Abstract: A method for circulating drilling fluid in a well system includes drilling a substantially vertical well bore from a surface to a subterranean zone and drilling an articulated well bore from the surface to the subterranean zone. The articulated well bore is horizontally offset from the substantially vertical well bore at the surface and intersects the substantially vertical well bore at a junction proximate the subterranean zone. The method includes drilling a drainage bore from the junction into the subterranean zone and pumping a drilling fluid through the drill string when drilling the drainage bore. The method also includes providing fluid down the substantially vertical well bore through a tubing. A fluid mixture returns up the substantially vertical well bore outside of the tubing. The fluid mixture comprises the drilling fluid after the drilling fluid exits the drill string.

Abstract: A system and method for removing contaminated pilings is provided, the system including a casing to enclose the piling and a pressurized air system for excavating soil and contaminated materials from around the piling and material from the piling itself, capturing the excavated soil and contaminated material as it rises within the piling by action of the pressurized air, and a closure mechanism at the bottom of the casing for enclosing and removing the piling without spreading contamination to the surrounding environment. Clean fill material, such as sand, can be injected through the air nozzles or optional sand ports on the casing to fill the void left from the removed piling.

Abstract: Improved methods of generating gas in and foaming aqueous well fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining with an alkaline aqueous well fluid one or more gas generating chemicals and a mixture of foaming and foaming stabilizing surfactants so that the gas generating chemical or chemicals react with the alkaline aqueous well fluid and gas and foam are formed in the well fluid while it is being pumped, and then pumping the well fluid into the subterranean zone.

Abstract: This invention aims to provide a gas-hydrate extracting device and method whereby a high-performance jet fluid is injected from a nozzle at the tip of an extraction pipe inserted into a gas-hydrate stratum, and whereby said jet fluid breaks said stratum so as to form a gas-hydrate mixed fluid that is transferred to surface of the earth, and whereby the void resulting from the removal of said gas hydrate is filled with the components of said high-performance jet fluid and a void-refilling fluid.

Abstract: Improved method and system for accessing subterranean deposits from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a horizontal cavity well. The drainage patterns provide access to a large subterranean area from the surface while the vertical cavity well allows entrained water, hydrocarbons, and other deposits to be efficiently removed and/or produced.

Abstract: A method for controlling a subsea well that includes shutting at least one blowout preventer, opening at least one isolation line, and circulating an influx out of a well while an inlet pressure of a subsea mudlift pump is adjusted to maintain a substantially constant drill pipe pressure at an initial circulating pressure. After the influx is circulated out of the well, drilling mud with a kill mud weight is pumped into the well. The drill pipe pressure is reduced according to a preselected drill pipe pressure decline schedule until the kill mud weight drilling mud reaches the bottom of the well. The drill pipe pressure is then maintained at a final circulating pressure by adjusting the inlet pressure of the subsea mudlift pump. The kill mud weight drilling mud is then circulated from the well bottom to the surface at the final circulating pressure.

Abstract: Improved methods of drilling well bores utilizing foamed aqueous drilling fluids are provided. The methods basically comprise circulating an aqueous drilling fluid containing a single foaming and defoaming surfactant and a gas downwardly through a rotary drill pipe and drill bit connected thereto. Well bore cuttings generated by the drill bit are lifted to the surface by foam produced from the aqueous drilling fluid and gas. Upon reaching the surface, the foamed aqueous drilling fluid is defoamed whereby the cuttings and gas are removed therefrom and the aqueous drilling fluid is combined with additional foaming surfactant when needed and additional gas. The foaming and defoaming of the aqueous drilling fluid are accomplished by changing the pH of the aqueous drilling fluid from basic to acidic which causes the single foaming and defoaming surfactant to foam and defoam the aqueous drilling fluid.

Abstract: A method for a dynamic shut-in of a subsea mudlift drilling system. The method comprises detecting a kick, isolating a wellbore, and adjusting a subsea mudlift pump and a surface mud pump to provide a selected wellbore pressure. Selected well parameters are measured and used to calculate a kick intensity. The invention is also a method for a dynamic shut-in of a subsea mudlift drilling system including detecting a kick and isolating a wellbore. A first inlet pressure of a subsea mudlift pump and a first drill pipe pressure are measured. A rate of the subsea mudlift pump and a rate of a surface mud pump are adjusted to pre-kick circulation rates. A second inlet pressure of the subsea mudlift pump and a second drill pipe pressure are recorded. The measured values are used to calculate a kick intensity.

Abstract: A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC—CO2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC—CO2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC—CO2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC—CO2 much more effective than water jet erosion.

Abstract: A process for circulating an aqueous foam in a wellbore includes the steps of forming a foam from an aqueous composition having a determined pH value, injecting the foam into a well so that it circulates from the surface to the well bottom and then back from the well bottom to the surface, and then changing the pH value of the foam when it returns to the surface. The aqueous composition from which the foam is made includes at least one ionic surfactant whose charge does not practically depend on the pH value and a polyampholytic polymer whose global charge depends on the pH value. This composition gives the foam the property that when the pH of the foam is varied at the surface of the well, the charge of the polyampholytic polymer is modified and the foam becomes destabilized and breaks more readily.

Abstract: The method for releasing the stuck pipe of the present invention uses a combination of components which oxidize the mud cake and generated gas bubbles to create an upward buoyancy for the oxidized mud cake. The spotting method of the present invention comprises adding to the borehole in the region of the stuck pipe: 1) an oxidizer which oxidizes the mud cake; and 2) at least one component which reacts in the borehole to generate a gas. Optionally, but preferably, the spotting method further uses a lubricant which is added to the borehole in the region of the stuck pipe. The lubricant acts to lubricate the oxidized parts of the mud cake. Also disclosed is a spotting fluid system including 1) an oxidizer which oxidizes the mud cake, 2) at least one component which reacts in the borehole to generate a gas, and, optionally a lubricant which acts to lubricate the oxidized parts of the mud cake.

Abstract: Aphron-containing spotting fluids and their use in releasing pipe or tools stuck in the filter cake on the sides of a borehole are disclosed. The spotting fluids comprise a liquid, either aqueous, oleaginous, or mixtures thereof, a viscosifier which imparts a low shear rate viscosity to the fluids of at least 10,000 centipoise, an aphron-generating surfactant, and aphrons. The spotting fluids are used in a conventional method of releasing pipes or tools stuck in the filter cake on the sides of a borehole during conventional drilling or well servicing operations.

Abstract: A process and device for boring holes in soil or rocks, in particular for percussion or rotary percussion boring. A bore hole is formed by an annular drill bit mounted on boring rods and at the same time a jacket tube which surrounds the boring rods with a certain gap is introduced. The annular drill bit is flushed during boring by a flushing medium fed into the annular gap defined between the boring rods and the jacket tube. When boring is completed, a setting suspension is fed into the annular gap to form an anchorage with the boring rods. An anchorage can thus be obtained in a simple and reliable manner immediately after a bore hole is completed, in particular in loose or slack material, by a device having a simple design.

Abstract: A method of forming boreholes using a cutting head having a low angle cutting face includes positioning orifices within the cutting head to direct pressurized streams of drilling fluid to impinge directly on the cutting face. The pressurized fluid streams clear excavated material away from the cutting face to increase the efficiency of the cutting head. In one embodiment, the orifices are positioned within the cutting face, while a second embodiment positions the orifices behind the cutting face. An alternative method provides for the stealthy formation of boreholes without disturbing the surrounding formation. The method includes positioning an orifice within the cutting head behind the cutting face to direct drilling fluid toward excavated material which has accumulated within the cutting head to a point behind the cutting face.

Abstract: An air-water mist flushing system and method for cooling and cleansing mining tool cutter elements having sources of water and compressed air, apparatus for admixing water and compressed air at predetermined volumes and pressures to form the air-water mist, and apparatus for delivering the air-water mist to the drill bit situs.

Abstract: A method and apparatus for drilling a well is set forth. In one aspect, a typical drill stem is assembled from a set of drill pipe and delivers a flow of drilling mud to the drill bit. A smaller tubing string is placed on the interior and connects to a mixing valve just above the drill bit. A gas flow is placed in the tubing which flows to the mixing valve where the gas is mixed in a desired ratio with the drilling mud so the mud weight is reduced, and thereby enables drilling, at a faster rate with an underbalanced condition. Steps are set forth in which the pressure is changed to an overbalanced condition.

Abstract: A foamable drilling fluid for use in well operations such as deep water offshore drilling where risers are not employed in returning the fluid to the surface mud pit. A preferred foamable drilling fluid comprises a prehydrated clay such as bentonite, sea water, a surfactant selected from the group consisting of .alpha.-olefinsulfonates, alkylpolyglycosides, alcohol sulfates, salts of ethoxylated alcohol sulfates, and a stabilizing surfactant consisting of cocoamine betaine. The stabilized foam drilling fluid resists foam breakdown upon drilling cessation, prevents fluid loss to reduce filter cake buildup and increases the carrying capacity of cuttings and other solids. In addition, a foamable drilling fluid is provided including an hydraulic material selected from the group consisting of Portland cement, siliceous material like fumed silica, blast furnace slag and pozzolans such as fly ash.

Abstract: The invention concerns wellbore fluids suitable for use in the oil and gas exploration and production industries and embraces fluids used for drilling, completion, workover or packing of wellbores. The invention is especially concerned with biodegradable wellbore fluids the liquid phase of which consists of an oil, or of water-in-oil "invert" emulsions, where the oil phase comprises n-alkanes.

Abstract: A process employing a polymer enhanced foam in a wellbore as a drilling fluid during a wellbore drilling operation. The polymer enhanced foam is formed from an uncrosslinked acrylamide polymer, a surfactant, an aqueous solvent, and an added gas.

Abstract: A process employing a foamed gel in a wellbore as a drilling fluid, lost circulation fluid, or combined drilling/lost circulation fluid during the wellbore drilling operation. The foamed gel is formed from a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas.

Abstract: This invention concerns an accessory, to be inserted in a drill string behind a drill bit, to provide separation of the liquid and air components of a flushing medium. The accessory comprises an inner housing (36) within an outer housing (34). A liquid/gas medium enters through opening (50) onto spiral raceway (48). Holes are provided at intervals along spiral (42). Liquid in the medium is centrifuged by the spiral (42) and projected into the chamber between inner and outer housings (36,34). The expelled liquid (52) falls to the base (70) of the housing (34) where it passes through apertures (38) into the drill bore. Once the medium has traversed the spiral (42) essentially only gas remains to pass through the opening (62) to the drill bit.

Abstract: A conventional well bore drilling system includes a coiled tubing mounted on a reel and connected to a mud supply for supplying mud through the tubing to a downhole end of the tubing to which is attached the downhole drilling tool. The system is modified by the addition of an inner tubing attached to the reel shaft and extending through the outer tubing to the drilling tool. The drilling mud is supplied in the space between the inner and outer tubes and a gas is supplied through the inner tube, The gas is vented through a coupling at the drilling tool into the well bore so as to enter the well bore and reduce the hydrostatic head of the fluids within the well bore to an under balanced condition below the pressure of the producing zone.

Abstract: In the removal of particulates from a wellbore, such as in air drilling for hydrocarbon recovery, a mixture of an amphoteric foaming agent and, typically, an anionic surfactant is employed. An aqueous solution thereof having a pH of at least 9.5 is used to generate a foam for removing the particulates; then the foam is collapsed by the introduction of acid to reduce the pH below about 4, the particles are removed mechanically, the pH is restored to greater than 9.5, and the foaming solution is returned to the wellbore. The solution may be used several times; partial losses of foaming agent in the process may be easily replenished with each cycle. Cationic surfactants may be used instead of anionic, with foaming and foam collapse being controlled at opposite pH's. Savings are realized in water, drilling chemicals, and settling pits and the like for removing particulates from the foam.

Abstract: A method and apparatus for removing drilling mud within entrained cuttings is provided using a pump for forcing fluid into a borehole, such that the fluid mixes with cuttings formed during the formation of the hole. The pipe receives the fluid and entrained cuttings at a first end of the pipe and returns the fluid and entrained cuttings to the surface at the second end of the pipe. At the first end of the pipe, air is injected into the drilling fluid with entrained cuttings to form bubbles therein, thereby increasing the velocity of the fluid and entrained cuttings through the pipe. In one alternative embodiment, a suction is provided at one end of the pipe to increase the speed of fluid and entrained cuttings therethrough. In a third embodiment of the present invention, an Archimedes screw is used to remove the fluid and entrained cuttings from the borehole.

Abstract: A method of maintaining a constant predetermined hydrostatic pressure in a wellbore being drilled by a rotary drilling process utilizing aerated drilling fluid. The aerating gas, such as compressed air, is maintained at a constant pressure while its flow is changed in response to changes in the flow of the drilling fluid. This maintains a constant ratio of compressed air to drilling fluid, resulting in the hydrostatic pressure remaining constant.

Abstract: A method for removing debris from a drillhole, includes positioning a separator adjacent to a down-the-hole percussive drillhead, for removing water and other matter from the percussive fluid prior to the percussive fluid entering the drillhead. The water and other matter are ejected into the drillhole to remove the debris, and backflow of debris and water into the separator and drillhead is prevented, during periods when the percussive fluid flow ceases.

Abstract: The present invention relates to a method for use in connection with a drilling apparatus for drilling a hole and also filling the drilled hole with a filler. A hole is drilled by using a tubular drill rod with a crushing tool provided at the end of the drill rod, with the crushing tool substantially defining the diameter of the hole to be drilled. A first flushing medium is supplied in the course of drilling, through the hole in the tubular drill rod to at least one opening in the crushing tool and into an annular space defined between the walls of the drilled hole and the outer surface of the drill rod, for carrying crushed material out of the drilled hole. After completion of the drilling operation and removal of the crushed material, a filler is delivered into the hole in the tubular drill rod, into the drilled hole and/or into the ground or bedrock surrounding the hole.

Abstract: An apparatus for air rotary drilling in saturated unconsolidated deposits. It consists of a drill rod connected to a drill bit and a drill casing surrounding the drill rod which defines a well in a drilled region. A pressurized air source is connected to the drill rod, the drill rod having a bore for supplying air under pressure to the drill bit, to force air and material up the drill casing in an area defined between the drill rod and the drill casing. A rotary drive arrangement drives the drill rod in rotation to provide a drilling action in cooperation with the high pressure air, the high pressure air source providing high pressure air to the drill rod bore. A snorkel discharge arrangement discharges air and material from the space defined between the drill pipe and the drill rod.

Abstract: This invention relates to a rotary drill bit having a body with leg members, where each of the leg members has a projecting conical cutter receiving journal. Each conical cutter has an axially extending recess open at one end and is rotatably mounted on the journal by friction reducing bearings interior to the conical cutters. The drill bit has a main cavity which extends down the center of the drill bit body. A jet nozzle provides an exit opening at the bottom of the main cavity. At least one passageway extends to and opens into the main cavity at one end and extends to and opens into the bearings at the other end. The end of the at least one passageway which extends to the main cavity is provided with a plurality of openings and a plurality of deflectors associated with the openings. When a gas-liquid mixture is passed through the main cavity, the deflectors will cause an abrupt change in the gas flow direction.

Abstract: Atomized water is produced by an atomizer mounted on a drilling device and introduced through a mist flow passage formed in a hollow drill. By applying the atomized water flowing from the atomizer to a cutting bit at the leading end of the drill through the mist flow passage, the cutting bit heated and reaching a high temperature in drilling is cooled. Thus, a rigid material of concrete or the like can be efficiently drilled without being stained with wetting.

Abstract: Apparatus and methods are provided for producing a proppant carrying foamed fracturing fluid or the like having very high ratios of proppant material to the liquid phase of the foam, which can be substantially higher than even the theoretical maximum ratio available when the proppant is introduced into a foaming apparatus as a proppant/liquid slurry. This is accomplished by a dry sand foam generation process wherein the sand or other particulate material is introduced into a foam generator apparatus as a dry particulate material in a stream of gas which is subsequently mixed with a second liquid stream.

Abstract: A cable following apparatus has a rotating annulus at the front portion of its main body where a cylindrical axial opening of the body passing over a cable first comes in contact with concentric neutral wires. The annulus, by rotating in the direction of the neutral wrapping wires, has the effect of wrapping down any wires that are broken. Further, a helical groove in the annulus extends forward beyond a static cutter plate providing a front surface of the main body. The end of the groove rotates slightly behind the static cutting surface of the plate. Wires that are broken and pulled away from the cable are picked up by the groove and carried to a position where they are cut off by the force of the side of the helical groove pressing them against the static cutter surface of the plate.

Abstract: A hydraulic borehole mining method and device used to recover subterranean coal, oil shale and other minerals from depths exceeding 1500 ft. where a gas lift is utilized to lift the mined slurry to the surface.

Abstract: In order to prevent the moisture in the general air supply from entering the first flow and generating mud in the area of the cones of a drill bit assembly, separator means is provided within the plenum chamber supported on the housing walls proximate to the conduit through which a first flow path flows. This may be done by using a stand pipe supported on an orifice plate of the first conduit and extending above the openings of a second conduit. Perforations in the stand pipe are above the second conduit. A fluid flow diverter at the end of the stand pipe is preferably of conical shape, larger diameter than the stand pipe and arranged so that its edges extend below some of the perforations on the stand pipe so that air entering the first flow must reverse course to pass through the perforations. Water cannot readily reverse in this manner.

Abstract: A downhole hammer drill for use with a dual concentric tube drill pipe string is characterized by the use of pressurized air from the annular passageway of the pipe string to operate the hammer. The exhaust air from the hammer is conducted to the periphery of the bit face of the hammer drill, across the bit face, and then through one or more openings in the central portion of the bit face. The exhaust air with entrained cuttings and hole water is then channeled through the drill and into the central passageway of the pipe string, through which it is removed from the drilling area. In a preferred embodiment an injection sub is provided in the drill string uphole of the drill and a drill body which substantially fills the bore annulus is used to throttle the flow of water down the borehole annulus to the bit face. In this embodiment a head of water is maintained in the borehole annulus and this water cascades down around the hammer drill to prevent cuttings and fines from moving up the bore annulus.

Abstract: A method and apparatus for providing a flow of lubricating fluid from a surface-mounted lubricating fluid source through a rotatable drill pipe to rotary cutting cones of a rotary drill bit for drilling in an underground formation, including pump means for providing a flow of lubricating fluid from the fluid source to an end of the drill pipe. Drill pipe conduit means extending along the length of the drill pipe is provided for receiving the flow of lubricating fluid and for directing the lubricating fluid flow along the drill pipe to the drill bit. Distribution conduit means at the drill bit extends from the drill pipe conduit means to the cutting cones and receives the flow of lubricating fluid from the drill pipe conduit means for directing the lubricating fluid flow to the cutting cones for lubrication thereof.

Abstract: A method and apparatus for driving a hollow pile into the ground. By using a hollow rod having a short auger fixedly secured to a leading end portion thereof, excavated earth and sand are lifted to and around the upper portion of the auger where compressed air is spouted from nozzle orifices formed in the hollow rod thereby lifting the excavated earth and sand through the hollow pile and consequently discharging the same from the hollow pile. As earth and sand are discharged from the hollow pile, the pile is sunk or driven into the ground.

Abstract: Means are provided to drill generally horizontal bores through heterogeneous fill and hard strata. A carriage providing power means to rotate a spindle is mounted on a generally horizontal track and is adapted to move longitudinally along the track. Swivel means about the spindle are provided with means to introduce a combined gas and liquid stream, suitably air and water, into a drill pipe connected to the spindle and through an impact drill mounted at the end of the drill pipe to power the drill and to flush cuttings from the hole.

Abstract: A foam generating apparatus (10) is provided for circulation of foam within a well (12) for drilling, operation or clean out. A liquid foam generating solution (38) is pressurized by a pump (48). The solution flows through a passage in a mixing tee (66). The mixing tee has a second passage which permits a pressurized gaseous aeration agent (35) to be entrained within the fluid flow. The turbulence of flow and downstream pressures permit onset of foam generation within the well. The foam consistency can be controlled by varying the pressure of the aeration agent and foam generating solution to maximize the effectiveness of the circulation. The ratio of aeration agent and fluid generating solution can also be varied.

Abstract: The invention provides a method for obtaining a balanced, pressurized core sample from an underpressurized geological reservoir formation. A pressure core sampling well is drilled to a preselected depth and the bottom hole reservoir pressure therein is determined. A computer is programmed to compute predicted bottom hole foam pressures at the bottom of the well produced by a stable foam coring fluid, having a preselected composition, which is introduced into the well under preselected control pressures. Measurements are than made of actual bottom hole foam pressures at the bottom of the well produced by the foam when it is introduced into the well at preselected control pressures and under core sample drilling conditions. A comparison is made between the measured bottom hole foam pressures and the computer predicted bottom hole foam pressures to derive a correlation function and to select a correlated core pressure.

Abstract: Foaming agents for use in oil and gas production comprising n-octyl dimethylamine oxide, n-decyl dimethylamine oxide, branched decyl dimethylamine oxide, and mixtures thereof, all of which generate copious quantities of stable foam even in the presence of brine and hydrocarbons.

Abstract: A deep vibrator includes a propulsion head (1) vibrating in a transverse direction with respect to the longitudinal axis of a suspension tube propulsion head being secured to the lower end of a suspension tube (2) while the outer wall of the suspension tube (2) includes pipes (4) arranged in the longitudinal direction thereof having at the lower end of the propulsion head (1) a spraying nozzle through which water may be fed under pressure, further spraying nozzles being distributed along the length of the pipes (4,5) and so aligned that they spray water into the annular space surrounding the suspension tube (2) thereby washing ground material toward the propulsion head.

Abstract: A method of preventing drilling fluid overflow when adding or removing drill pipe sections to or from a drill string disposed in a well bore comprising the steps of introducing a gas into the drill string until a predetermined volume thereof is introduced therein, introducing drilling fluid into the drill string after introducing the gas until a predetermined volume thereof is introduced therein and the gas is pressurized thereby displacing drilling fluid originally contained in the drill string downwardly within the drill string and upwardly within the annulus between the drill string and the well bore to lower the level of the drilling fluid in the drill string a distance such that upon releasing the introduced pressurized gas and drilling fluid from the drill string and removing drilling fluid and gas therefrom, the resulting level of drilling fluid in the drill string is below the level at which the drill pipe sections are added to or removed from the drill string, releasing the introduced pressurized gas

Abstract: A particular simple method and class of organic polycationic polymer compositions are provided for treating earthen formations such as in oil wells to stabilize clay against dispersion and expansion due to water.

Abstract: A method of preventing drilling fluid overflow when adding or removing drill pipe sections to or from a drill string disposed in a well bore comprising the steps of introducing gasified drilling fluid into the drill string until a predetermined volume thereof is introduced therein at a predetermined pressure thereby displacing non-gasified drilling fluid in the drill string downwardly and displacing drilling fluid from the annulus, releasing the pressurized gasified drilling fluid from the drill string whereby the gasified drilling fluid flows upwardly through the drill string and drilling fluid and gas are removed therefrom whereby the resulting equalized level of drilling fluid in the drill string is below the level at which the drill pipe sections are added to or removed from the drill string and then adding or removing drill pipe sections to or from the drill string.

Abstract: The invention is a novel method and apparatus for subterranean drilling and mining, particularly suited to alluvial deposits. The method uses water jets from the lower end of the apparatus to loosen and remove soil. Part of the water is bled off to raise a piston and associated weight, the water being evacuated from the cylinder in which the piston operates from time to time to give periodic impulses to the outer casing. Air may be admitted to the system during the mining mode to increase its efficiency.