Abstract: The present invention relates to reverse-cementing apparatus. The reverse-cementing apparatus is a float apparatus connected in a pipe string to be cemented into a wellbore. The float apparatus includes an outer housing connected to the casing string. A check valve for preventing flow from the wellbore into the pipe string is disposed in the housing. The check valve is releasably disposed in the housing so that it can be removed from the housing once the pipe string is in place. A flow path for fluid from the wellbore into the pipe string is therefore provided. Cement displaced into the annulus will cause fluid in the wellbore to enter the pipe string through the housing so that the pipe string can be cemented in place utilizing a reverse-cementing method.

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 compositions and methods for sealing pipe in a well bore. The compositions which harden into highly resilient solid masses having high strengths are basically comprised of a hydraulic cement, an aqueous rubber latex, an aqueous rubber latex stabilizing surfactant and silica hydrophobicized with silicon oil.

Abstract: The present invention provides improved well sealing compositions and methods. The compositions are basically comprised of slag cement, water, a slag cement set activator, a hardenable epoxide containing material and an epoxide containing material hardening agent.

Abstract: Improved methods of cementing in a subterranean zone penetrated by a well bore are provided. The methods are basically comprised of the steps of preparing a foamed cement composition comprised of hydraulic cement, a non-dispersing set retarder, sufficient water to form a slurry, sufficient gas to foam the slurry and a foaming and foam stabilizing surfactant mixture present in an amount sufficient to facilitate the formation of the foam and stabilize the foamed cement composition.

Abstract: A circulating nipple used to circulate fluid through well casing while running the casing into a well. The circulating nipple has a body portion and an elongated neck portion. The elongated neck portion is adapted for engagement with a pipe wrench for making the nipple up on the casing string. The body defines one or more holes therethrough adapted for receiving a handle or operating bar therein. The operating bar may be used as an alternative to, or in addition to, the use of the pipe wrench for making the nipple up on the casing string. Methods of running casing using the circulating nipple are also disclosed.

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: Methods of controlling the rates of release of chemical additives into treating fluids are provided by the present invention. The methods are basically comprised of causing a chemical additive in liquid form to be absorbed into a porous solid material whereby the chemical additive is encapsulated thereby and when the resulting encapsulated chemical additive is combined with the treating fluid, the chemical additive is slowly released into the treating fluid. After being encapsulated, the liquid chemical additive is combined with the treating fluid and the treating fluid containing the encapsulated chemical additive is introduced into a well.

Abstract: The present invention provides improved foamed well cement compositions and methods. The foamed cement compositions have improved properties and are basically comprised of hydraulic cement, amorphous silica surface treated with a mixture of organosilane coupling agents, sufficient water to form a slurry, sufficient gas to foam the slurry and a mixture of foaming and foam stabilizing surfactants present in an amount sufficient to facilitate the formation of the foam and stabilize the foamed composition.

Abstract: Methods and compositions for forming permeable cement sand screens in well bores are provided. The compositions are basically comprised of a hydraulic cement, an acid soluble particulate solid, a liquid hydrocarbon solvent soluble particulate solid, a particulate cross-linked gel containing an internal breaker which after time causes the gel to break into a liquid, water present in an amount sufficient to form a slurry, a gas present in an amount sufficient to form a foam and a mixture of foaming and foamed stabilizing surfactants.

Abstract: A cementing plug having a universal construction and improved wiping and extended wear characteristics. The cementing plug has a plug subassembly with a body member and an elastomeric jacket on the body member. The body member defines a central opening therethrough with a shoulder therein. To configure the plug as a bottom cementing plug, a shearable insert is positioned on the shoulder, and to configure the plug as a top cementing plug, a non-shearable insert is positioned on the shoulder. The shearable insert is one of a plurality of such inserts designed to shear at correspondingly different shear pressures. In a first embodiment, the shearable insert is a substantially flat disk having a uniform thickness, and in a second embodiment, the shearable insert has an outer ring portion and a relatively thin inner domed portion.

Abstract: Biodegradable dispersing and fluid loss control additives for well cements, well cement compositions including the additives and methods of using the well cement compositions are provided. The well cement compositions are basically comprised of a hydraulic cement, water in an amount sufficient to form a slurry and a dispersing and fluid loss control additive comprised of casein. A second agent which also provides fluid loss control can optionally be included in the additive.

Abstract: The present invention relates to a drill string diverter apparatus for reducing surge pressure when lowering a liner into a partially cased wellbore. The diverter apparatus is connected in a pipe string above a liner being lowered into a wellbore. The diverter apparatus comprises a tubular housing with ports defined therethrough to communicate and redirect fluids received in the liner to the annulus between the diverter apparatus and casing previously set in the wellbore. The diverter apparatus has an open position whereby the ports are open and communication is established and a closed position whereby flow through the ports is prevented. A sliding sleeve is disposed about an outer surface of the tubular housing and engages the casing. The sleeve moves vertically relative to the tubular housing once the diverter apparatus has been lowered into the casing to selectively open and close the flow ports. A J-slot means is provided for locking the diverter apparatus in its closed position.

Abstract: Drilling fluid additives are designed to increase the density of drilling fluids while minimizing the increase in the resistance to flow of the drilling fluid. In particular, barite particles are added to the drilling fluid as a weight material where the barite particles include at least 85% by weight particles less than 75 microns and greater than 6 microns in equivalent spherical diameter.

Abstract: The present invention provides methods of preventing the flow of water or gas or both through a subterranean zone having a high temperature and a depth such that a long pumping time is required to place a sealing composition therein. The methods basically comprise the steps of preparing a polymeric sealing composition comprised of water, a cross-linking agent and a selected water-soluble polymer which reacts with the cross-linking agent and forms a sealing gel which is stable for a desired period of time at the temperature of the zone and has a pumping time before gelation in the presence of the cross-linking agent whereby the composition can be pumped to the depth of the zone and placed therein. Thereafter, the sealing composition is pumped into the zone and allowed to form a sealing gel therein.

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: The present invention provides improved methods of sealing a subterranean zone to remedy the uncontrolled flow of fluids into and out of the zone. The methods basically comprise preparing a sealing composition and placing the composition into the zone to be sealed. The placement of the composition is controlled in a manner whereby portions of the sealing composition are continuously converted to sealing masses which are successively diverted into permeable portions of the zone until all of the permeable portions are sealed.

Abstract: The present invention provides improved defoaming compositions and methods. The compositions of the invention are basically comprised of polypropylene glycol, particulate hydrophobic silica and a liquid diluent.

Abstract: Drilling fluids are designed for drilling and cementing through shallow water flows and unconsolidated formations. Such drilling fluids utilize hollow microspheres to increase the volume of the drilling fluid without adding too much weight to the drilling fluid. The drilling fluid is also designed to employ an admixture of silicate, high surface area fibrous material, deformable graphite particles, and an activatable cementitious material to stabilize unconsolidated formations and form a tough filter cake that will bond with the cement casing.

Abstract: An inverter fluid that intermixes with a non-aqueous (e.g., oil) external/aqueous internal fluid to cause external/internal inversion is designed. This includes testing a selected inverter fluid with a test fluid having a composition nominally equivalent to the composition of the non-aqueous external/aqueous internal fluid. A quantity of the designed inverter fluid is made and placed in the annulus of a well, such as an oil or gas well, to remove the non-aqueous external/aqueous internal fluid on at least a portion of one or more surfaces of the annulus. This can include pumping the inverter fluid along with a stream of cement. The inverter fluid displaces at least part of the non-aqueous external/aqueous internal fluid in the annular region and inverts the coating of non-aqueous external/aqueous internal fluid sufficient to remove the coating ahead of the cement.