Abstract: A water-base fluid for use in drilling wells and other drilling operation includes a shale which swells in the presence of water.

Abstract: Methods of treating wells for cementing operations and for improving placement of cement in wells containing water swelling clays include treatment of the well with a fluid containing clay precipitating agents capable of coagulating clays in the well. The coagulating fluid can contain quaternary ammonium salts, aqueous salts of potassium or cesium, or silicates as the clay coagulating agent. The coagulating fluids can be applied to convert soft mud cake into hard mud cake prior to placement of cement.

Abstract: The method is used for locally testing underground soil contamination by determining the generation rate of a first contaminant fluid in porous soil. The method includes the steps of making a hole of known dimensions in the soil, with the hole defining a first and a second spaced-apart portions; covering the hole, so as to define a closed volume in the hole; constantly injecting a second fluid in the hole at a constant given flow rate at said first portion of the hole, while simultaneously collecting fluid samples at the above-mentioned constant given flow rate at the second portion of the hole; measuring the concentrations of the first contaminant fluid from the fluid samples collected at known time intervals; and computing the generation rate of the first contaminant fluid, from the known volume of the hole and from the concentrations previously measured and originating from samples collected at the known time intervals.

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: A method of drilling a bore hole is described. A desiccant is added to a Hydrocarbon Based Fluid (Crude Oil—Refined Oil—Diesel Fuel—Mineral Oil—etc.) used as a drilling fluid to drill bore holes (Oil and Gas Wells—Mine Shafts—etc.) to react with any water (H2O) present to generate a water free fluid. Several advantages result from accomplishing the water removal process including higher drilling rates, lower fluid preparation and maintenance costs, lower drilling fluid pumping costs, improved solids removal from the drilling fluid at the surface, improved bore hole conditions and improved environmental cleanup of the drill solids waste.

Abstract: A water-base drilling fluid for use in drilling wells through a formation containing a shale which swells in the presence of water. The drilling fluid preferably includes: an aqueous based continuous phase, a weight material, and a shale hydration inhibition agent having the formula: H2N—CH(CH3)CH2{—OCH2CH(CH3)—}x—NH2 in which x is a value less than 15. The shale hydration inhibition agent should be present in sufficient concentration to reduce the swelling of the shale. Preferably x has an average number between about 1 and about 5 and more preferably x has an average number of about 2.6. Also inclusive of the present invention is a method of reducing the swelling of shale clay encountered during the drilling of a subterranean well, the method comprising circulating in the well a water-base drilling fluid formulated in accordance with the present invention.

Abstract: Shale reactivity is evaluated by testing a preserved test plug of shale sample in a triaxial test machine, the test plug being prepared by collecting a downhole shale sample and keeping it all times immersed in a preserving mineral oil so as to avoid dehydration, then applying radial and axial pressure on the test plug surrounded by mineral oil up to equilibration to overburden pressure, the test fluid being then contacted with the sample and the interaction of fluid and sample being evaluated by axial and radial deformations as measured by a triaxial detector apparatus sensitive to vertical and radial strains occurring across the shale sample, while the shale sample is subjected to any of a set of different conditions including a temperature or thermal potential, a hydraulic potential and/or a chemical potential. Only one fluid is tested on each sample.

Abstract: The invention provides a permeable treatment wall comprising one or more high-permeability columns, as well as a methods for preparing such a permeable treatment wall.

Abstract: Calcium oxide (C.sub.a O--Hot Lime--Processed Lime) is added to a Hydrocarbon Based Fluid (Crude Oil--Refined Oil--Diesel Fuel--Mineral Oil--etc.) used as a drilling fluid to drill bore holes (Oil and Gas Wells--Mine Shafts--etc.) to react with any water (H.sub.2 O) present to generate a water free fluid. Several advantages result from accomplishing the water removal process including higher drilling rates, lower fluid preparation and maintenance costs, lower drilling fluid pumping costs, improved solids removal from the drilling fluid at the surface, improved bore hole conditions and improved environmental cleanup of the drill solids waste.

Abstract: A method of making a well fluid for use in a well which includes the steps of determining uphole and downhole operating temperatures in the well, and then contacting a well lubricant with a lubricating additive, wherein the lubricating additive has a cloud point temperature greater than the uphole operating temperature and less than the downhole operating temperature. A method of lubricating drilling equipment during opeation of a subterranean well, includes the steps of determining uphole and downhole operating temperatures in the well, and then contacting the drilling equipment with a treating fluid comprising a well lubricant and a lubricating additive, with the lubricating additive having a cloud point temperature greater than the uphole operating temperature and less than the downhole operating temperature.

Abstract: The invention relates to clay stabilizing agents for use in an alkaline water-base fluid such as a drilling mud and the use of such clay stabilizing agents in the drilling of wells. The clay stabilizing agent comprises a polyfunctional polyamine reaction product prepared by the reaction of a polyamine base reactant with urea or a dialkylcarbonate or by reaction with urea and a dialkylcarbonate. The stabilizing agent is subject to subsequent acidification to reduce the pH thereof to a value of about 7 or less. The polyamine base reactant is selected from the group consisting of an aliphatic polyamine, a polyaliphatic polyamine, a heterocyclic polyamine, an alkylalkanol polyamine and mixtures thereof. Specifically, the base reactant comprises an aliphatic polyamine selected from the group consisting of ethylenediamine, diethylenetriamine, tetraethylenetetramine, and tetraethylenepentamine and mixtures thereof.

Abstract: Improved mud additive compositions are provided which are especially formulated to control hole enlargement due to salt bed erosion during drilling, and to assist in solubilization of deposited salt during well operations. The compositions include a first ingredient such as sodium or potassium ferrocyanide and mixtures thereof, and a second ingredient such as the trisodium salt of nitrilotriacetic acid and alkali metal citrates. The first ingredient is generally present at a level of from about 50-95% by weight in the particulate, dilutable form of the invention, whereas the second ingredient is present at a level of from about 5-50% by weight. The compositions hereof may be added to drilling mud during drilling operations or to fresh water for removing salt depositions.

Abstract: A cement anchor is provided for test tools in a well in a soft or weak formation below a zone to be tested.

Abstract: A cementitious slurry comprising microfine ground blast furnace slag and normally ground blast furnace slag. A microfine ground blast furnace slag is made of composition having a blaine specific surface area between 8,000 and 20,000 cm.sup.2 /g. By normally ground is meant slag compositions having a surface area of less than 8,000 cm.sup.2 /g. Such cementitious compositions have utility in construction, road building, and cementing wellbores.

Abstract: A method for consolidating incompetent formations penetrated by a borehole using drilling fluids. The method uses a water-based drilling fluid the solids contents of which includes microfine-ground blast furnace slag. This provides a fluid that will penetrate the incompetent formation and harden in place to consolidate the formation. Subsequent cementing with a cementitious slurry comprising water, activator and normally-ground blast furnace slag results in a compatible cement which will adhere to filter cake from the drilling.

Abstract: Hydrogen sulphide is scavenged from a feedstock comprising crude oil and hydrogen sulphide by adding a compound of general formula ##STR1## to the feedstock. R is an alkyl group containing 1 to 18 carbon atoms, an aryl group, or an alkyl aryl group wherein the alkyl moiety contains 1 to 18 carbon atoms and L is a leaving group.Preferred scavengers include acetic anhydride and triacetamide.

Abstract: The concentration of unspent zinc-based hydrogen sulfide scavenger in an oil-based drilling fluid is controlled by selectively dissolving and extracting the unspent scavenger in a solvent, such as glacial acetic acid, separating the aqueous solution, measuring the concentration of dissolved zinc in the aqueous solution, for example, with an X-ray fluorescence spectrograph, and utilizing the results of the measurements to proportion the extent of changes in concentration of the scavenger in the drilling fluid.

Abstract: Hydrogen sulphide is scavenged from a feedstock comprising crude oil and hydrogen sulphide by adding a compound of general formula: ##STR1## to the feedstock. X and Y are carbon or nitrogen atoms and the interatomic bond is triple or double as appropriate. Any two or more of R.sup.1 -R.sup.4 are organic groups containing electronegative functional groups. The remaining two or less of R.sup.1 -R.sup.4 are hydrocarbyl groups, hydrogen atoms or zero.Preferred scavengers include di-isopropylazo dicarboxylate and dimethylacetylene dicarboxylate.

Abstract: The enchancement of rock drilling by neutralizing the rock surface charge with respect to the drilling fluid. The isoelectric condition is obtained by nullifying the zeta potential of the rock surface by chemical additives such as surfactants or any material. Drilling enchancement is maintained as long as the rock zeta potential registers a zero reading. An apparatus and method is disclosed herein to achieve and maintain this isoelectric condition and provide for the maximal drilling rate and drill bit life.

Abstract: For drilling mud during use in drilling a well an additive of FE Chelate is disclosed. The chelating agent preferably includes EDTA, HEDTA, NTA, or DTPA. It is oxygen regenerated at the surface to enable repeated use to remove H.sub.2 S. Any H.sub.2 S is converted to elemental sulfur, reducing risk of poisoning.

Abstract: The concentration of unspent zinc-based hydrogen sulfide scavenger in an aqueous drilling fluid is controlled by selectively extracting an unspent scavenger in a solvent, such as glacial acetic acid, measuring the concentration of dissolved zinc, for example, with an X-ray fluorescence spectrograph, and utilizing the results of the measurements to proportion the extent of changes to be made in the concentration of the scavenger.

Abstract: A composition suitable for scavenging oxygen from aqueous systems, for example those used in well drilling, is provided which comprises a mixture of an oxygen-reactive sulfite and/or bisulfite (sulfite component) and an amount of iron oxide particles sufficient to catalyze the reaction between oxygen and the sulfite component. These particles have certain properties as further described herein. These compositions also serve as corrosion inhibitors in aqueous systems, such as drilling muds, to protect steel components from corrosion. A method is also provided for using such compositions in aqueous systems to scavenge oxygen from such systems, and also H.sub.2 S, if present.

Abstract: A method for reducing concentrations of hydrogen sulfide present in subterranean well fluids by injection of a stabilized solution of chlorine dioxide. The stabilized chlorine dioxide solution is introduced into the subterranean well by injecting the solution through the well bore. This method also includes the reduction of the hydrogen sulfide content in drilling mud which has been contaminated by hydrogen sulfide present in a hydrocarbon well by mixing a stabilized solution of chlorine dioxide with the drilling mud. This method requires the preparation of a stabilized chlorine dioxide solution, a determination of the approximate amount of hydrogen sulfide which might be brought to the surface by the drilling mud and the introduction of the predetermined amount of stabilized chlorine dioxide solution into the drilling mud.

Abstract: An earth battery which includes a first electrode which is a veined material located in the earth, a second electrode electrically connected to the surface of the earth and disposed in a hole which extends from the surface of the earth into the first electrode, an electrolyte disposed in the hole and in contact with the first and second electrodes, and means for electrically connecting the first electrode to the surface of the earth. A seam of coal is preferred as the first electrode. A method of mining metals located in the earth using the earth battery and a method of drilling holes in the earth are also disclosed.

Abstract: A method of stabilizing clay soil comprising admixing the clay soil with an effective amount of dry hydroxy-aluminum.

Abstract: An amphoteric water-in-oil self-inverting polymer emulsion is prepared which contains a copolymer of (1) a nonionic vinyl monomer and (2) an amphoteric vinyl monomer or a terpolymer of (1) a nonionic vinyl monomer, (2) an anionic vinyl monomer and (3) a cationic vinyl monomer in the aqueous phase, a hydrocarbon oil for the oil phase, a water-in-oil emulsifying agent and an inverting surfactant. An example of a copolymer is a copolymer of (1) a nonionic vinyl monomer such as acrylamide or methacrylamide and (2) an amphoteric vinyl monomer such as a reaction product of dimethylaminoethyl methacrylate and monochloroacetic acid. An example of a terpolymer is a terpolymer of (1) a nonionic vinyl monomer such as acrylamide or methacrylamide, (2) an anionic vinyl monomer such as sodium acrylate and (3) a cationic vinyl monomer such as a triethyl ammonium ethyl methacrylate methosulfate salt.

Abstract: Iron oxide particles having a high surface area, a high kinetic K value and composed substantially of amorphous Fe.sub.2 O.sub.3 and crystalline Fe.sub.2 O.sub.3 are drilling mud additives suitable for scavenging hydrogen sulfide. Such particles do not adversely affect the rheological properties of the mud and when reacted with hydrogen sulfide form reaction products which are acid stable. Upon completion of drilling, the drilling mud containing these iron oxide particles and their reaction products with H.sub.2 S may be left in place between the inner casing and the formation wall or the outer casing as a packer fluid.

Abstract: Fluids for drilling, completing or servicing wells are treated for the removal or inactivation of hydrogen sulfide contamination by the addition of at least one organic zinc chelate.

Abstract: Iron rich dusts created during steelmaking, as in the basic oxygen and open hearth processes, are useful for scavenging hydrogen sulfide. For example, basic oxygen furnace dusts, which are in more abundant supply, are found to consist of fine, nearly spherical particles of iron oxide whose crystalline composition comprises Fe.sub.3 O.sub.4 (major portion) and Fe.sub.2 O.sub.3 (minor portion) as seen by X-ray diffraction. Their great surface area makes them highly reactive to hydrogen sulfide gas. Their reaction yields unexpected products, namely, free sulfur and iron hydroxides. According to the present invention such iron rich dusts are used in water slurries through which sour hydrocarbon gas is bubbled, and in water based drilling muds to scavenge hydrogen sulfide encountered in well drilling.

Abstract: Hydrogen sulfide, sometimes referred to as "rotten egg" gas occurs commonly in nature, particularly about oil and gas wells in drilling, completing and working over of wells and is dangerously toxic to workmen and devastatingly corrosive to bore hole casings and drilling equipment. It also contaminates natural gas produced by some wells.Here it has been found that a water soluble zinc ammonium carbonate complex provides nearly quantitative removal of hydrogen sulfide by intimately contacting the carrier thereof with substantially stoichiometric qualities of said complex in aqueous solution.

Abstract: This invention relates to methods and additives for scavenging oxygen dissolved and entrained in liquids which are particularly suitable for removing dissolved and entrained oxygen from polymer-containing fluids used in drilling and completing well bores as well as water flood and other procedures carried out in the oil field. The oxygen scavenger additive is sodium dithionite or a mixture thereof with sodium dithionate dispersed in a liquid carrier such as a hydrocarbon.

Abstract: This invention is a process for treating an underground formation of coal by contacting the coal with a basic aqueous solution for a time sufficient to disintegrate at least a portion of the coal formation. Subsequently, at least some of the disintegrated material is removed to create permeability in the coal formation. The coal is then treated with a heat carrying fluid to recover energy values from the coal. Another aspect of this invention is a process for slurry mining coal which comprises contacting the coal with the basic aqueous solution for a time sufficient to disintegrate the coal and form a slurry, then conveying said slurry to a receiving terminal.

Abstract: An iron oxide having the ideal composition Fe.sub.3 O.sub.4 has a unique high porosity, substantially spherical particle structure. Used in oil and gas well drilling muds, it scavenges hydrogen sulfide. It also improves the rheological properties of the mud, maintains its stability under high temperatures, and functions as a mud weighting material. Upon completion of drilling, the drilling mud containing the porous Fe.sub.3 O.sub.4 additive may be left in place between the inner casing and the formation wall or the outer casing as a packer fluid.

Abstract: A solvent of coal is pumped through pipes drilled into the earth to a coal seam. The coal is digested or dispersed into the solvent and solvent recycle, and is thereafter pumped as a solution up to the surface and processed to remove the coal from the solvent. The method produces low-ash coal, stripped of all the extraneous ash, leaving the inherent ash, and stripped of all the sulfur except the organic type. The method comprises making a coal solution in situ and bringing it to the earth surface economically, without the hazards and environmental problems of conventional coal mining and without the need of coal washing facilities.

Abstract: The concentration of unspent zinc-based hydrogen sulfide scavenger in an aqueous drilling fluid is controlled by selectively extracting the unspent scavenger in a solvent, such as glacial acetic acid, measuring the concentration of dissolved zinc, for example, with an X-ray fluorescence spectrograph, and utilizing the results of the measurements to proportion the extent of changes to be made in the concentration of the scavenger.