Abstract: A one trip method for drilling a wellbore below a cemented casing is disclosed. An apparatus for use in performing the method is also disclosed. The method comprises lowering a drill bit into a casing cemented in the wellbore. The casing has float equipment connected therein. The drill bit is rotated in the casing above the float equipment so that it expands radially outwardly to a diameter greater than the inner diameter of the casing. The float equipment, which can be a float shoe or a float collar or any other type of float equipment known in the art, includes an outer case with a valve connected therein. The outer case is comprised of a drillable material. Thus, the drill bit utilized to drill the wellbore can begin its drilling operation above the float equipment and successfully drill a wellbore below the casing having a diameter greater than the inner diameter of the casing.

Abstract: A method and composition is provided for sealing a subterranean zone penetrated by a well bore and restoring lost circulation, wherein the composition basically comprises a mixture of latex, melamine-formaldehyde resin, and a catalyst.

Abstract: Methods and apparatus for creating a downhole buoyant casing chamber. The buoyant casing chamber may be created after the casing has been at least partially run into the wellbore. Some embodiments also allow circulation of fluid as the casing is being run after the creation of the buoyant chamber. A method of the invention comprises running a length of casing into the well to a first step, forming a buoyant chamber in the casing, filling the chamber with buoyant fluid, either a gas or a light liquid, and running the casing to a second depth greater than the first depth. The apparatus used comprises a length of casing, a floating device disposed in a lower end of the casing and forming a lower boundary of a buoyant chamber, a packer for sealingly engaging the casing in an upper end of the buoyant chamber, and a volume of buoyant fluid to fill the chamber.

Abstract: The present invention provides improved methods and compositions for grouting heat exchange pipe in a hole or trench in the ground. The grouting compositions of the invention have quick set and high thermal conductivity properties and are basically comprised of an amorphous silica material, an alkaline earth metal oxide or hydroxide, a water swellable clay and water present in an amount sufficient to form a slurry. The compositions optionally also include a set retarder and a thermal conductivity increasing agent.

Abstract: The present invention provides improved compositions and methods of using the compositions for sealing subterranean zones. One composition of the invention is comprised of water, a silane coupling agent, an organophilic clay, an epoxy resin and a hardening agent for said epoxy resin.

Abstract: Methods of agglomerating hydraulic cement powder to improve its flow and handling characteristics are provided. One embodiment of the methods of the present invention is comprised of the steps of forming a mixture of the hydraulic cement powder with a particulate solid disintegrating agent, the disintegrating agent having the property of causing the break up of the agglomerated cement powder upon contact with water. Thereafter, the mixture is compressed into agglomerated pellets.

Abstract: High strength foamed well cement compositions and methods of cementing subterranean zones penetrated by well bores are provided. The foamed well cement compositions are basically comprised of a hydraulic cement, hydrophilic fibers, water sufficient to form a pumpable slurry, a mixture of foaming and foam stabilizing surfactants and sufficient gas to foam the slurry.

Abstract: An improved float valve according to the present invention includes a packer 10 for positioning within a joint of the casing C while at the surface of the well, the packer including a float valve receptacle therein for at least partially receiving a float valve. The float valve body includes a valve seat 56 and a valve member 54 is positioned for selective engagement and disengagement with the valve seat. A guide nose 58 may be optionally provided for positioning within the casing joint between the valve body and the pin end of the casing joint. The float valve body may be reliably fixed and sealed to the packer body. After the packer setting operation, the casing joint and the packer and the float valve may then be positioned as an assembly within the well.

Abstract: Improved well cement additives, compositions and methods of using the compositions are provided. The well cement additives are basically comprised of a first monomer selected from the group of 2-acrylamido-2-methylpropane sulfonic acid, 2-allyloxy-2-hydroxy-1-propane sulfonic acid and vinylsulfonic acid, a second monomer selected from the group of N,N-dimethylacrylamide, acrylamide, N-vinylpyrrolidone, N-vinylacetamide and acrylonitrile and a third monomer selected from the group of C6 to C22 dimethylaminopropylmethacrylamide bromide, chloride and iodide and C6 to C22 dimethylaminoethylmethacrylate bromide, chloride and iodide.

Abstract: Cement compositions and methods of cementing within subterranean formations penetrated by well bores wherein the flow properties of one or more dry particulate cementitious materials are improved and wherein the materials can be readily conveyed out of storage tanks and the like. A preferred composition of the present invention comprises a particulate flow enhancing additive dry-blended with one or more dry particulate cementitious materials, said flow enhancing additive being comprised of a particulate solid material carrying a flow inducing polar chemical, and a sufficient amount of water to form a pumpable slurry.

Abstract: Methods of forming one or more plugs in a well bore are provided. The methods basically comprise the steps of dropping into the well bore a cementitious material which will delayedly react with water therein to form an impermeable solid and which has been formed into agglomerates of sufficient weight to sink through the water and other fluids and materials in the well bore. The agglomerates are dropped in a quantity sufficient to form a mass of the agglomerates in the well bore. Thereafter, the mass of agglomerates is allowed to react with the water in the well bore and set into an impermeable solid plug therein.

Abstract: The present invention provides methods of cementing subterranean zones using cement compositions comprising calcium aluminate, fly ash, sodium polyphosphate and water.

Abstract: A method and apparatus for foaming and then testing the foamed fluid. The apparatus comprises a cylindrical pressure vessel with upper and lower caps. A circular disk with a plurality of openings, which are preferably circular openings, is placed in the pressure vessel. The apparatus also includes a motor with a shaft extending therefrom. The shaft is attached to the pressure vessel so that when the motor is actuated, the pressure vessel can be rotated in a desired revolutions per minute. The method includes placing a mixture in the pressure vessel and then attaching the caps to the upper and lower ends of the vessel. The upper cap has a pressure gauge and has a pressure inlet and a pressure relief valve. The circular disk is placed in the vessel. The vessel is pressurized to a desired pressure with a gas motor. The motor is then actuated to rotate the vessel.

Abstract: Methods of improving the flow properties of one or more dry particulate cementitious materials are provided. The methods are basically comprised of dry-blending a particulate flow enhancing additive comprised of a particulate solid adsorbent material having a flow inducing polar molecule producing chemical adsorbed thereon with said cementitious materials.

Abstract: The present invention provides improved early-enhanced strength cement compositions and methods. The cement compositions can be utilized in surface construction projects as well as in the construction of oil, gas and water wells. The improved cement compositions of this invention are basically comprised of a hydraulic cement, water present in an amount sufficient to form a slurry and hydrophobic silica powder.

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: The present invention provides improved lightweight well cement compositions useful for performing a variety of cementing applications in subterranean formations and particularly for cementing conductor pipe in offshore wells. A preferred cement composition basically comprises a hydraulic cement, an effective amount of an iron salt selected from the group of ferric chloride, ferrous chloride or mixtures thereof to reduce the transition time of the composition, sufficient water to form a pumpable slurry, an effective amount of a foaming additive for producing a foamed slurry, and sufficient gas to foam the slurry.

Abstract: Delayed thixotropic cement compositions and methods of cementing in subterranean zones penetrated by well bores are provided. The novel cement compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and a water soluble delayed thixotropy imparting additive selected from the group consisting of carbonic acid and alkali metal carbonates.

Abstract: A method and apparatus for plugging a well. The apparatus includes a well barrier which may be connected to a pipe string and lowered into a well to a selected plug location. The barrier is held in place by the pipe string at the selected plug location. The well barrier will engage the well at the selected plug location. A plugging fluid is displaced through the pipe string and is communicated into the well above the barrier. The well barrier will catch the plugging fluid. After the plugging fluid gels sufficiently to support itself in the well, the pipe string which was utilized to lower the well barrier can be disconnected from the well barrier and removed from the well after the plugging fluid has been allowed to set to a sufficient gel strength. The well barrier consists of a support pipe connected to the pipe string, and a fluid barrier connected thereto.

Abstract: A mixing apparatus includes a mixing tube, a liquid inlet, a dry substance inlet and a recirculation mixture inlet. The mixing apparatus is utilized with a tub. A liquid and a dry substance may be mixed in the mixing tube and the mixture may be recirculated so that a liquid, a dry substance and a recirculated mixture may all be mixed in a mixing tube and subsequently utilized in a wellbore. The mixing apparatus includes a valve connected to the liquid inlet. The valve comprises a cylindrical outer housing, a jetting sleeve and a rotatable plug therein. The jetting sleeve is disposed in the outer housing and has a plurality of ports which will direct liquid downwardly and inwardly so that it mixes with the dry substance as the dry substance passes downwardly in the mixing tube. The plug may be rotated in the jetting sleeve to completely cover all the jetting ports to prevent flow into the mixing tube and is rotatable to an open position in which liquid may be allowed to flow through the jetting ports.