Abstract: Methods of remedially treating coal bed methane wells to enhance the production of methane therefrom are provided. The methods basically comprise pumping a clean out fluid into the well and into producing zones communicated with the well by perforations therein. The pumping of the clean out fluid is continued while adding perforation sealers thereto to thereby seal perforations and producing zones which are not plugged and to divert the clean out fluid into perforations and producing zones which are partially plugged. An aqueous acid solution is next pumped into the partially plugged perforations and producing zones whereby acid soluble solid materials in the perforations and producing zones are dissolved. The well is shut in, reverse flowed and then returned to production.

Abstract: Improved cement compositions and methods of using such compositions in carrying out construction and remedial operations in oil and gas wells at high temperatures are provided. The compositions are basically comprised of hydraulic cement, sufficient water to form a pumpable slurry, and a dispersing and stabilizing additive comprised of an ethoxylated alkali metal salt of an alkyl polyether sulfonate.

Abstract: An improved method for fracturing oil wells is disclosed and claimed herein. In particular, the present invention involves the determination of the direction of fracture propagation, i.e., perpendicular to the minimum stress existing within a given formation and the alignment of perforations produced by a variety of perforating devices with the previously determined direction of fracture propagation. The methods disclosed and claimed herein will eliminate many problems encountered in the prior art, including reducing the pressure required to initiate fractures and reducing the undesirable effects of near wellbore tortuosity. A solidified compound may be placed proximate the fractures to further limit undesirable sand production.

Abstract: The present invention provides fly ash cementing compositions and methods which are useful in any cementing application, and are particularly suitable for cementing in subterranean zones penetrated by well bores. The cementing compositions can include a portion of the drilling fluid used to drill a well bore as a component thereof. Also, drilling fluid can be disposed of by combining it with the fly ash cementing composition whereby it solidifies in a disposal location.

Abstract: Fracturing, frac-pack, and gravel packing procedures are provided which utilize a treating composition comprising a carrier fluid and a particulate blend. The particulate blend consists essentially of a large particulate material and a small particulate material. The large particulate material consists essentially of particles smaller than about 4 mesh but not smaller than about 40 mesh. The small particulate material consists essentially of particles smaller than about 16 mesh but not smaller than about 100 mesh. The small particulate material is present in the particulate blend in an amount in the range of from about 5% to about 60% by weight based on the amount of the large particulate material present in the particulate blend. A prepacked screening device including a large particulate/small particulate blend of the type just described is also provided.

Abstract: Improved well drilling fluids and methods which prevent damage to water sensitive formations while drilling are provided. The drilling fluids include a formation stabilizing compound which contains an organic quaternary ammonium cation and an inorganic, organic or combination anion.

Abstract: A well completion method comprising the steps of: (1) positioning a conduit in a wellbore such that (a) a wellbore annulus surrounding the conduit is defined between the conduit and the wall of the wellbore, (b) the wellbore annulus has a first longitudinal segment which is positioned within a producing formation, (c) the wellbore annulus has a second longitudinal segment which is positioned within a producing formation, and (d) the wellbore annulus has a third longitudinal segment which is positioned between the first longitudinal segment and the second longitudinal segment; (2) placing a gravel pack in the wellbore annulus such that the gravel pack surrounds the conduit and substantially fills the first, second, and third longitudinal segments of the wellbore annulus; and (3) injecting a hardenable hydraulic cement composition into the portion of the gravel pack located in the third longitudinal segment of the wellbore annulus such that, after the hydraulic cement composition hardens, the third longitudinal

Abstract: The present invention relates to a method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated breaker said encapsulated breaker comprising an aqueous fluid soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane having imperfections through which an aqueous fluid can diffuse, such that an aqueous fluid in said fracturing fluid can diffuse through said membrane, dissolve at least a portion of said breaker and diffuse outward from said encapsulated breaker to contact and break the fracturing fluid in contact therewith.

Abstract: Disclosed herein is a delayed crosslinking agent. This crosslinking agent contains a borate source and a water-soluble polysaccharide. Suggested borate sources include borax, boric acid, and sodium tetraborate. Guar gum, carboxymethylhydroxypropylguar, and hydroxypropylguar are recommended water-soluble polysaccharides. The borate source is present in an amount of from about 5 to about 30% percent by weight, calculated as B.sub.2 O.sub.3, of the water-soluble polysaccharide.These delayed crosslinking agents are transported to the well site and admixed with an aqueous solution containing additional water-soluble polysaccharide. The delayed crosslinking agents re-equilibrate in the aqueous solution of the water-soluble polysaccharide. The resulting compositions are useful as fracturing fluids.

Abstract: A functionalized polyamine effective to retard the setting rate of a slurry of hydraulic cement is disclosed. A slurry of hydraulic cement in water which includes the functionalized polyamine, which is a polyethylene amine having attached thereto moieties selected from the group consisting of carboxylic acid groups and phosphonic acid groups, is useful to cement a conduit in a subterranean formation penetrated by a wellbore wherein it is desirable to retard the setting rate of the cement to enable placement of the slurry.

Abstract: A method of forming a kickoff plug in a borehole is disclosed. The method includes a first phase in which the interval to be cemented is treated to remove gelled mud and mud cake from the walls of the borehole and in which drilling fluid is conditioned for subsequent cementing operations. The method includes a second phase in which a hydrostatically balanced plug of a hydraulic cement slurry is placed in the interval to be cemented and then permitted to harden to form the kickoff plug. Each phase of the method features the injection of high velocity streams of fluid, e.g. drilling fluid and cement slurry, into the borehole in a plane or planes which are substantially parallel to the cross section of the borehole and at linear velocities sufficient to cause circulation of gelled mud, mud cake, and drilling cutting from the borehole.

Abstract: A well treating composition comprising: a gelled carrier; a particulate material; an epoxy resin system including at least one epoxy resin; and a finely-divided hardening agent which, when dissolved, is operable for hardening the epoxy resin. The finely-divided hardening agent is dispersed in the epoxy resin system. A method of treating a subterranean zone located in a well comprising the steps of: (a) preparing the above-described treating composition; (b) injecting the treating composition into the well such that the treating composition is placed in the subterranean zone; and (c) maintaining the finely-divided hardening agent under conditions such that, prior to injecting the treating composition into the well, the finely-divided hardening agent does not substantially dissolve.

Abstract: The invention relates to a method and composition for acidizing a subterranean formation employing an acidic solution comprising hydrochloric acid solution containing a corrosion inhibitor present in a corrosion-reducing effective amount. The corrosion inhibitor comprises the product of the reaction of (i) a compound having at least one reactive hydrogen atom and having no groups reactive under the conditions of reaction other than hydrogen, (ii) a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group, (iii) an aldehyde, (iv) a fatty compound and an acid source which is admixed with a source of antimony ions.

Abstract: The present invention provides a method of gravel packing a subterranean formation using a gel of a graft copolymer of a hydroxyalkyl cellulose prepared by a redox reaction with vinyl phosphonic acid. The gel is formed by hydrating the graft copolymer in an aqueous liquid. The gel in crosslinked by the addition of a crosslink initiator comprising a Lewis base or Bronsted-Lowry base, which is substantially free of polyvalent metal ions, to the gel in an amount sufficient to effect crosslinking of the graft copolymer. The viscosity of the crosslinked gel is reduced by contacting the gel with an acidic fluid whereby the pH of the gel is caused to decrease. The reduction in gel viscosity facilitates formation of the gravel pack.

Abstract: Improved apparatus and methods for determining the shear stress required for removing drilling fluid deposits formed on the walls of a well bore are provided. The methods basically comprise introducing a drilling fluid into a test apparatus which simulates a permeable section of a well bore. Drilling fluid deposits are caused to be formed on the walls of the permeable section, and the drilling fluid is circulated through the permeable section at progressively increasing flow rates for time periods whereby the pressure drop of the drilling fluid stabilizes. The stabilized pressure drop below which no appreciable erosion of the deposits takes place is determined by acoustically measuring and comparing the thicknesses of the drilling fluid deposits at each of the flow rates when the pressure drop stabilized.

Abstract: A method of forming a gel in the subsurface formation is provided whereby a self crosslinking monomer selected from hydroxy unsaturated carbonyl compounds is polymerized in the formation by a suitable initiator. In a preferred embodiment, the initiator is selected from ago compounds which are temperature activated over a range of temperatures.

Abstract: A method of stimulating a subterranean formation using a foamed cement composition. When hardened, the cement composition has a permeability of at least about 0.3 darcies. The inventive formation stimulation method comprises the steps of: (a) injecting the foamed cement composition into the formation at a pressure sufficient to fracture the formation and (b) allowing the cement composition to harden in the formation.

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions including such additives and methods of using the cement compositions for cementing zones in wells. The set retarding additives are graft copolymers or terpolymers comprised of the condensation polymer product of a ketone, aldehyde and a compound which introduces acid groups into the polymer having grafted thereto a monomer selected from the group consisting of acrylic acid, vinyl phosphonic acid, methacrylic acid, maleic acid and itaconic acid or one of the foregoing monomers and a second monomer of 2-acrylamido-2-methylpropane sulfonic acid.

Abstract: The present invention provides low viscosity acid-in-oil emulsions, surfactant systems and methods of using the emulsions and surfactants for stimulating the production of hydrocarbons from subterranean producing formations. The low viscosity acid-in-oil emulsions are basically comprised of a hydrocarbon oil forming the external phase of the emulsion, an emulsifying agent of a type which forms and stabilizes an acid-in-oil emulsion, an emulsion viscosity reducing agent comprising a fatty ammonium salt of a fatty acid and an aqueous acid solution forming the internal phase of the emulsion.

Abstract: The present invention provides methods of cementing a well with a cementing composition utilizing a portion of the drilling fluid used to drill the well as a component of the cementing composition. The methods basically comprise forming a cementing composition, consisting essentially of a cementing precursor composition, a set-activator, and a portion of the drilling fluid, introducing the cementing composition into the well and permitting the cementing composition to set into a hard mass therein.