Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, a caustic and an alkyl alcohol.

Abstract: A plug-dropping head in which the objects to be dropped are placed in individual discrete passages. A motor-driven or hand-operated rotating member orients an entrance to a passage going through it to, in series, individual passages in the housing for sequential dropping of objects downhole. A relief port is provided so that as the rotating outlet member moves from one passage in the housing to the next, the relief passage allows continuing flow delivered by the surface pump.

Abstract: Aluminum silicate-containing cement slurries for cementing wellbores in deepwater and cold environments, or in wellbores susceptible to fluid intrusion. The aluminum silicate-containing slurries may also be used as high strength, low density cements for wellbore cementing applications under a variety of conditions. The cement slurries typically comprise a mixture of a reactive aluminum silicate and hydraulic cement, and may include one or more other additives. The cement slurries may optionally be foamed using a foaming agent and energizing phase.

Abstract: Improved settable spotting fluid compositions and methods are provided. The settable spotting fluid compositions are basically comprised of a hydraulic settable component comprised of fly ash, a fluid loss control additive, a gel strength inhibiting additive, a set retarding additive and water selected from the group of fresh water and salt water present in an amount sufficient to form a slurry having a density in the range of from about 12 to about 15 pounds per gallon.

Abstract: Methods and compositions for cementing pipe strings in well bores are provided. The compositions are basically comprised of a hydraulic cement, water, an in situ foam generating additive and a water-wetting foam stabilizing surfactant.

Abstract: A method of indicating the release of a plug, such as a cementing plug for an oil or gas well, includes releasing a plug from a retained position in a tube system, and in response to releasing the plug, opening an electrical circuit to which the plug was connected in the retained position. The method also includes generating, in response to opening the electrical circuit, a plug release indicator signal. The indicator signal can be generated in response to, for example, a low frequency electromagnetic signal.

Abstract: A system for reducing pressure while running a casing liner, hanging a casing liner from a casing and cementing the liner in a borehole during a single trip downhole is disclosed. Some of the components of the system are 1.) a bypass or diverter sub for reducing surge pressure having either an incremental breakaway seat or a yieldable seat, 2.) a container or manifold for launching a smaller ball used to close the bypass, a larger ball used to hang the liner in the casing, and a drill pipe wiper dart for cementing, and 3.) a guide shoe with multiple openings and no float valve to provide proper flow of drilling fluid up the liner and out the port of the bypass to reduce surge pressure and to provide for proper cementation. Advantageously, methods for operation of this surge pressure reduction system and its components are also disclosed.

Abstract: The present invention provides methods of cleaning up a producing interval of a well bore drilled using a synthetic oil-water emulsion drill-in fluid. The methods basically comprise contacting filter cake and drill-in fluid on the walls of the well bore with three treatment fluids in three stages, the first and second treatment fluids being comprised of water, a filter cake dissolving acid, a mutual solvent and an emulsion penetrating agent. The third treatment fluid is comprised of water, a filter cake dissolving acid and a water wetting surfactant.

Abstract: A wiper plug launching tool includes a body arranged to be lowered into a liner on a running string, the body having a tubular upper portion and a cylindrical lower portion, upper and lower wiper plugs loaded into the lower portion, each of the plugs having upwardly facing elastomer cups that are reduced in diameter during loading, a drive rod movably mounted in the upper portion of the body, a first piston or dart that is pumped down the running string and into engagement with the drive rod so that pressure applied to the first dart forces the rod downward to cause ejection of the lower wiper plug into the liner where cups of the plug expand to provide a moving seal at the lower end of a column of cement, and a second piston or dart that is pumped down into engagement with the first dart to force the rod further downward and cause ejection of the upper wiper plug into the liner where the cups of this plug expand to provide a moving seal at the upper end of the column of cement.

Abstract: Spacer fluids comprising a dispersant selected from the group consisting of water soluble polymers comprising allyloxybenzene sulfonate or allyloxybenzene phosphonate polymerized with at least one of acrylic acid, acrylamides, alkyl acrylamides, maleic anhydride, itaconic acid, sulfonated or phosphonated styrene, sulfonated or phosphonated vinyl toluene, sulfonated or phosphonated isobutylene, acrylamidopropane sulfonate or acrylamidopropanephosphonate, vinyl alcohol, sulfonated or phosphonated propene and alkali metal, alkaline earth metal and ammonium salts thereof and water with optional additional components such as surfactants, viscosifiers and wetting materials to form a rheologically compatible spacer fluid for use between a drilling fluid and a cement slurry and a method for using such spacer fluids to displace drilling fluids from a wellbore space with a cement slurry.

Abstract: An apparatus and method of dropping a pumpdown plug or ball is revealed. The assembly can be integrally formed with a plug-dropping head or can be an auxiliary feature that is mounted to a plug-dropping head. The release mechanism is actuated by remote control, employing intrinsically safe circuitry. The circuitry, along with its self-contained power source, actuates a primary control member responsive to an input signal so as to allow component shifting for release of the pumpdown plug or ball. Multiple plug-dropping heads can be stacked, each responsive to a discrete release signal. Actuation to drop the pumpdown ball or plug is accomplished even while the components are rotating or are moving longitudinally. Using the apparatus and method of the present invention, personnel do not need to climb up in the derrick to actuate manual valves.

Abstract: Improved methods and apparatus for placing and cementing a casing string in a horizontal well bore section are provided. A float shoe is attached to the end of the casing string and a float collar is connected in the casing string for trapping air in a first portion of the casing string thereby causing it to be buoyed up during placement by drilling fluid contained in the well bore. A selectively openable and releasable closed baffle assembly is connected within the casing string for trapping air or a low density fluid in a second portion of the casing string thereby causing it to also be buoyed up by drilling fluid in the well bore. The buoying up of the casing string reduces placement drag and consequent compressive loading on the casing string. After placement, the closed baffle means is opened to allow fluid circulation and conditioning of the annulus. A bottom cementing plug is then landed on the baffle assembly and the baffle assembly is released and moved to the float collar.

Abstract: The present invention provides improved primary well cementing methods and apparatus. The methods basically comprise the steps of releasing a displacement plug into the casing to be cemented and pumping a first displacement fluid behind the displacement plug while measuring the quantity of the first displacement fluid required to land the displacement plug on a float collar or the like connected near the bottom of the casing, releasing a bottom cementing plug into the casing and pumping a cement slurry behind the bottom cementing plug in a predetermined quantity and then releasing a top cementing plug into the casing and pumping a second displacement fluid behind the top cementing plug in a quantity substantially equal to the measured quantity of the first displacement fluid thereby ensuring that the cement slurry is not under or over displaced in the annulus between the casing and the well bore.

Abstract: An apparatus and method are disclosed for pumping segregated fluids through a tubular member, such as is required when cementing a liner into a well bore. A liner wiper plug has an internal bore formed therethrough, with a flapper valve mounted in the liner wiper plug. The flapper valve can pivot to an open position to allow fluid flow through the wiper plug, and the flapper valve can pivot to a closed position to prevent fluid flow through the wiper plug. A work string, or a stinger attached to a work string, can be positioned within the internal bore of the wiper plug, holding the flapper valve in the open position. The wiper plug can be run into the well on the work string, with the flapper valve held open, and with flow of a first fluid in progress. The wiper plug can be releasably supported from the liner. The work string is withdrawn from the wiper plug to allow the flapper valve to close.

Abstract: A well completion spacer fluid is provided which is particularly suitable for separating a cement slurry from drilling fluid in primary cementing operations. The well completion spacer fluid is also useful for separating other potentially incompatible fluids in the wellbore, such as, separating drilling fluid from a completion brine. The spacer fluid basically comprises water, a hydrous magnesium silicate clay, silica and organic polymer(s).

Abstract: The present invention provides an improved subsurface release cementing plug apparatus for use in a string of pipe during the cementing of the pipe in a well bore. The apparatus includes a hollow cementing plug seat member adapted to be connected in the string of pipe near the bottom thereof and a cementing plug assembly releasably connectable to a circulation tool or casing running tool in the top of the string of pipe. The cementing plug assembly includes a top cementing plug having an external annular seating surface formed thereon for sealingly engaging a top internal annular seating surface of the cementing plug seat member, and a bottom cementing plug releasably connected to the top cementing plug having an external annular seating surface formed thereon for engaging a bottom internal annular seating surface of the cementing plug seat member.

Abstract: The present invention provides an improved cementing inflation packer tool and methods of using the tool. The tool includes of a tubular housing having a packer inflating port disposed therein and a packer inflating port opening sleeve slidably disposed within the housing. The opening sleeve is movable between a closed position and an open position by a first cementing plug. An external packer sleeve having a pressurized fluid inflatable packer element attached thereto and a cementing port therein is sealingly disposed over the outer surface of the housing and the packer inflating port. The external packer sleeve provides a passageway from the packer inflating port to the inflatable packer element and check valve means are disposed in the passageway. A fluid rupturable member having a predetermined rupture pressure is sealingly attached over the cementing port.

Abstract: An improved well cementing plug assembly adapted to be connected to a string of drill pipe or a circulation tool for use in a pipe during the cementing of the pipe in a well bore is provided. The top and bottom plugs are selectively releasable by activating balls dropped into the plug assembly. Different sizes of plugs can be used utilizing the same inner tubes and other assembly parts, and the top plug slides on its inner tube when a pressure differential is exerted on it thereby insuring a seal between the top and bottom plugs when the plugs are landed on a float shoe or the like.

Abstract: Improved well casing fill apparatus and methods for filling a casing string with well bore fluid while running the string into a well bore and then cementing the casing in the well bore are provided. A well casing fill apparatus of this invention is basically comprised of a tubular housing having a well bore fluid fill port extending through a wall thereof and a closing sleeve slidably disposed in the tubular housing between an upper open position whereby the fill port is uncovered to a lower closed position whereby the closing sleeve covers the fill port. The closing sleeve includes a cementing plug landing seat thereon for receiving a cementing plug and slidably moving the closing sleeve to the closed position.

Abstract: The invention involves an assembly, specifically beneficial in deviated well-bores, which allows running into the wellbore with the complete completion assembly. The completion assembly includes one or more screens which may be pre-packed. Initially, a material which sets to form a permeable mass is deposited in the annular space outside the screens. After such material is deposited, cement or other sealing material is pumped into the annular space above the screens to complete the completion process. As a result, in one trip the deviated wellbore is completed with the permeable material deposited outside the screen or screens and cement being disposed in the annular space above the permeable material. Production can then begin.

Abstract: An apparatus and method of dropping a pumpdown plug or ball is revealed. The release mechanism is actuated by remote control, employing intrinsically safe circuitry. The circuitry, along with its self-contained power source, actuates a primary control member responsive to an input signal so as to allow component shifting for release of the pumpdown plug or ball. Multiple plug-dropping heads can be stacked, each responsive to a discrete release signal. Actuation to drop the pumpdown ball or plug is accomplished even while the components are rotating or are moving longitudinally.

Abstract: A method for injecting fluid, such as an accelerator, into a wellbore comprises storing the fluid in a reservoir, locating the reservoir downhole in the wellbore, and then transferring the fluid from the reservoir into the wellbore. More particularly, one embodiment of the method comprises storing the fluid in a reservoir in a plug, pumping the plug down casing in a wellbore, and transferring the fluid at the bottom of the wellbore via a venturi effect. Another embodiment of the method comprises storing the fluid in a reservoir integrated into the wall of a portion of casing, setting the casing in the wellbore, and then transferring the fluid via a venturi effect from the reservoir into the annulus defined between the casing and the wellbore.

Abstract: The present invention relates to two improved methods for multilateral completion and cementing (e.g. sealing) the juncture between primary and lateral wellbores. These two completion methods of the present invention address the issue of cementation of the lateral wellbores for the purpose of zonal isolation. It is desirable to have the ability to re-enter each lateral wellbore as well as maintain the option to perform any function that could be done in a single wellbore. For this reason, cemented lateral wellbores are desirable so that normal isolation, stimulation or any other operation can be achieved. The methods allow sealing and reworking of either wellbores with single laterals or multiple laterals and provide safe durable junctions therebetween.

Abstract: An apparatus and method for controlling the pressure at which a fluid is introduced into a well penetrating a subterranean formation. The apparatus comprises a blow out sub having a sealed chamber between two plugs. The chamber is filled with a fluid at a known pressure. Thus, the pressure required to release the first plug is independent of the pressure in the well below the sub. The sub is attached to a tubular and positioned within the well. The first plug is then released upon application of a predetermined pressure fluid pressure, and the second plug is released upon application of a lesser pressure. The blow out sub may additionally comprise a tube forming a channel through the first plug, the chamber, and the second plug, with a means for controlling fluid flow through the channel. A first fluid may be introduced into the well via the channel prior to releasing the first plug.

Abstract: Methods and compositions for removing gelled and dehydrated drilling fluid and filter cake from the walls of wellbores are provided. The methods basically include contacting the drilling fluid and filter cake with a removal composition comprised of an aqueous sugar solution for a period of time sufficient to cause the disintegration of the drilling fluid and filter cake. The composition, having the disintegrated drilling fluid and filter cake dispersed therein, is then displaced from the wellbore.

Abstract: A method for establishing production of oil or gas from a secondary production zone which is above a primary production zone in a well in which a settable material is placed in the annulus between the casing and the tubing above the secondary production zone and allowed to set up, and the secondary zone is then perforated with a through-tubing perforating gun.

Abstract: Cement plugs are positively placed in a wellbore by placement of a bridge plug immediately beneath the depth where the plug is intended and release of a seal allowing flow of cement slurry from a slurry containment tube as the tube is withdrawn to cause a positive piston-like displacement of the fluid in the wellbore.

Abstract: A well completion process for improved cement placement in a horizontal wellbore where dual density cleaning fluids are circulated down the wellbore for conditioning and cleaning it. Afterwards, a production tube containing centralizers is positioned centrally within the wellbore. Next, "spacer fluids" of higher and lower densities are circulated within an annulus formed by the space between the tube and the wellbore so as to more substantially clean the annulus out. Subsequently, a cement having a density greater than the spacer fluid is pumped into the annulus. Thereafter, a light weight cement is pumped into the annulus thereby overriding the heavier cement and removing voids in the annulus resulting in more efficient cement placement.

Abstract: An apparatus and method for producing through a casing without perforation are disclosed. The casing can be rotated while it is cemented and includes a multiplicity of sliding sleeve valves. Each of the valves selectively covers a plurality of pistons, each of which preferably has a rupture disc mounted therein. A pressure-regulating device is provided in association with each rupture disc to ensure retention of sufficient internal pressure in the tubing such that all discs eventually burst without any short circuiting through the discs which ruptured earlier. The outward movement of the pistons acts to assist in fracturing the formation. Thereafter, the pressure used to rupture the discs aids in further channeling the fluid energy of the fluid rupturing the discs, as well as putting additional pressure on the movable pistons to further stress fracture the formation.As the piston is pumped outward, the grease that is held captive within the piston assembly is forced outward through a bladder.

Abstract: A well completion process for improved cement placement in a horizontal wellbore. Initially, a cleaning fluid is circulated down the wellbore for conditioning and cleaning it. Afterwards, a production tube containing centralizers is positioned centrally within the wellbore. Next, "spacer fluids" of higher and lower densities are circulated within an annulus formed by the space between the tube and the wellbore so as to more substantially clean the annulus out. Subsequently, a cement having a density greater than the spacer fluid is pumped into the annulus. Thereafter, a light weight cement is pumped into the annulus thereby overriding the heavier cement and removing voids in the annulus resulting in more efficient cement placement.

Abstract: Oil and gas wells and injection wells are cleaned of oil-based drilling muds, pipe thread compounds, other oil contaminants, cement and contaminants in injection water by a composition comprising fresh water or seawater, one-half to ten percent concentration of an alkyl polyglycoside surfactant and one to ten percent of a caustic agent such as sodium hydroxide, potassium hydroxide or ammonium hydroxide.

Abstract: The present invention provides a cementing tool for cementing multiple stages within a well. The assembly includes a housing assembly which defines one or more cementing ports. A first sleeve assembly is retained within the housing and is movable from a first position, where the sleeve covers the port, and thereby precludes fluid flow therethrough, to a second position wherein the sleeve opens the cementing port. The apparatus also includes a second sleeve assembly which is movable from a first position away from the cementing port to a second position wherein the sleeve assembly covers the port. The first sleeve is cooperatively configured with the housing assembly to provide engaging surfaces which resist rotation of the first sleeve relative to the housing. Additionally, the first sleeve and the second sleeve assembly are configured to limit relative rotation when the two pieces are longitudinally adjacent one another.

Abstract: Improved methods of displacing a first liquid through a pipe with a second liquid while preventing the first and second liquids from mixing are provided. In accordance with the methods, a plug is formed in-situ in the pipe between the first and second liquids by injecting a self-thickening liquid therein and permitting the liquid to thicken. The formed plug and the first liquid are then displaced through the pipe with the second liquid. The methods are particularly suitable for carrying out subterranean well bore cementing operations wherein cement slurries are displaced through pipes disposed in well bores.

Abstract: A spacer fluid containing blast furnace slag is utilized in a well drilling operation. In one embodiment an oil emulsion drilling fluid is displaced using spacer fluid comprising water, blast furnace slag and a surfactant. In another embodiment a spacer fluid comprising blast furnace slag and water is used in the cementing of an annulus surrounding a pipe with a blast furnace slag cementitious slurry.

Abstract: The present invention provides a method of preventing gas migration during primary well cementing. The method basically comprises the steps of displacing a cement slurry into the annulus between a string of pipe to be cemented in a well bore and the walls of the well bore, determining the initial surface pressure in the pipe after the cement slurry is placed in the annulus, displacing additional cement slurry into the annulus as is necessary to make up for losses in the surface pressure due to cement slurry gel strength development and volume reduction whereby the surface pressure is maintained substantially equal to the initial surface pressure until the cement slurry develops a predetermined gel strength sufficient by itself to prevent gas migration, and then allowing the cement slurry to set into a hard impermeable mass in the annulus.

Abstract: A system for cementing well casing in a bore hole utilizes only top and bottom cementing plugs. The well casing has on its lower end, an inwardly extending lip to engage a latch on the lower portion of the bottom cementing plug. The bottom cementing plug has a through passage that is covered on the top by a diaphragm and on the bottom by another diaphragm.

Abstract: A well completion process for improved cement placement in a horizontal wellbore where a fluid is circulated down the wellbore for conditioning and cleaning it. Afterwards, a production tube containing centralizers is positioned centrally within the wellbore. Next, a "spacer fluid" is circulated within an annulus formed by the space between the tube and the wellbore so as to clean the annulus out. Subsequently, a cement having a density greater than the spacer fluid is pumped into the annulus. Thereafter, a light weight cement is pumped into the annulus thereby overriding the heavier cement and removing voids in the annulus resulting in more efficient cement placement.

Abstract: A spacer fluid containing blast furnace slag is utilized in a well drilling operation. In one embodiment an oil emulsion drilling fluid is displaced using spacer fluid comprising water, blast furnace slag and a surfactant. In another embodiment a spacer fluid comprising blast furnace slag and water is used in the cementing of an annulus surrounding a pipe with a blast furnace slag cementitious slurry.

Abstract: The method of using soap as a fluid loss additive in the hydraulic fracturing treatment of oil and gas wells includes choosing a soap having a titre value which will insure that the soap will dissolve and liquify at the formation temperature in the area where fluid loss is to be reduced. The formation temperature in this area is reduced to an extent where the soap will not liquify, while the soap is introduced into the area under pressure, and this lower temperature is maintained while a fracturing or cementing process is carried out. Subsequently, the temperature in the area where fluid loss is to be reduced is permitted to rise and liquify the soap which is then removed from the well.

Abstract: A dispersant for drilling fluids, spacer fluids, completion fluids, cement slurries and mixtures of drilling fluids and cement slurries used for drilling and cementing subterranean wells.

Abstract: Once the drilling of an oil or gas well is finished the bore must be cased and cemented. It is important that the cement lining be complete, and to ensure this it is necessary to sweep out the mud in the annulus ahead of the rising cement. Unfortunately, this often proves difficult, and various procedures and mechanisms have been devised in the past to improve the chances of achieving efficient mud-removal and forming a complete cement lining, though none have been truly successful. One of the techniques presently employed involves the utilization of a wash, but it has been noted that such a wash, even when turbulent, has very little component of its movement in the annulus in a direction other than up along the annulus, and that as a result it has very little effect on gelled mud deposits, especially those in the small casing/bore inter-distance of a severely eccentric casing.

Abstract: A swivel cementing head with manifold assembly. The assembly comprises a body connectable to a tool string, and a cementing manifold connectable to the cement source. The manifold is rotatably mounted on the body to provide continuous fluid communication between the manifold and body even when the body is rotating with respect to the manifold. The rotatable connection is provided by a mandrel extending from the body and the sleeve connected to the manifold. The mandrel defines a mandrel central opening therethrough and a transverse mandrel hole in communication with the mandrel opening, and the sleeve defines a transverse sleeve hole therethrough. The mandrel has a mandrel groove and an outwardly facing surface thereof adjacent to the mandrel hole, and the sleeve has a sleeve groove in an inwardly facing surface thereof adjacent to the sleeve hole.

Abstract: Gas channeling to the surface in the setting of surface casing can be avoided by employing a cementing process in which a right-angle setting cement is positioned within a wellbore annulus between the wellbore and the casing above a gas-bearing zone with a low fluid loss cement slurry being placed below the right-angle setting cement. Pumping of the cement slurry is stopped for a period of time to allow the setting of the right-angle setting cement at which point pressurized pumping is resumed to displace remaining portions of the low fluid loss cement slurry into the wellbore annulus against the plug created by the set right-angle setting cement to block off gas migration and squeeze the low fluid loss cement into the gas-bearing zone.

Abstract: A method of cementing oil well casings and a cementing tool used when performing the method are provided. A novel top cementing plug functions in a conventional manner during proper oil well casing cementing operations, but if inserted into the oil well casing in error, allows cement to be pumped through it. The top plug includes an outer, hard rubber casing having vertically spaced fins formed about its circumference. A central passage is provided through the outer casing and receives a cylindrical, metal sleeve. In one embodiment, a bore is formed in a portion of the metal sleeve to define a shoulder within the sleeve. The bore receives a cylindrical housing which carries a spring loaded, ball valve mechanism. The valve mechanism includes an annular spring retainer which rests on the shoulder. One end of a helical spring within the housing contacts the retainer while the other end of the spring biases a ball against an annular flange at the top of the housing to seal the passage.

Abstract: A gelable silicate solution prepared by mixing fumed silica and an alkali metal hydroxide with water is provided. The silicate solution is used to form a seal or plug in one or more subterranean formations or in a well bore penetrating the formations by pumping the solution into a desired location in the well bore or formations and allowing the silicate solution to gel therein.

Abstract: Drilling mud is rapidly decomposed by admixing one or more enzymes with the mud to selectively degrade one or more polymeric organic viscosifiers therein. A method of cleaning up a well site drilling mud pit containing drilling mud is provided. Also provided are a composition and method of removing residual drilling mud from a wellbore and around the well face.

Abstract: Cement plugs used in the cementing of casing in a borehole drilled into a subterranean formation are restrained from rotation by being forced into a portion of the casing and check valve apparatus which includes a reduced diameter section formed as a continuous annular liner of material having a coefficient of friction. Compression of the plug against the high-friction liner avoids rotation of the plugs when they are drilled subsequent to the cementing operation.

Abstract: This invention relates to a method of cementing a cylinder in a bore, such as a casing in a wellbore, which method involves the use of a hydraulic cement consisting of discrete particles having a particle size not greater than about 30 microns. The cement which is utilized in a water slurry, has a low density, good thixotropic properties and, in one embodiment, expansive characteristics.

Abstract: This invention relates to a method of repairing a hole in and thereby terminating the undesirable flow of fluid through a hole in a casing disposed in a wellbore penetrating a subterranean earth formation which method involves the same use of a hydraulic cement consisting of discrete particles having a particle size not greater than about 30 microns. The cement, which is utilized in a water slurry, has a low density, good thixotropic properties and, in one embodiment, expansive characteristics.

Abstract: A packer apparatus, particularly a cup type casing packer shoe, includes a pressure-actuated closing sleeve and pressure-actuated pumpout seats. An upper pumpout seat moves with the closing sleeve in response to a first pressure so that the closing sleeve closes ports through which fluid is communicated to an annulus outside the apparatus. Both the upper pumpout seat and a lower pumpout seat and any intervening fluid are pumped out of the apparatus in response to a second, higher pressure so that the apparatus communicates with the well below the annulus without a drillout procedure having to be performed through the apparatus or a tubing string in which the apparatus is connected. A related method is also disclosed.