Abstract: An apparatus and method for removing cuttings in a deviated borehole using drilling fluids. The apparatus includes a pipe string and a bottom hole assembly having a down hole motor and bit for drilling the borehole. The pipe string has one end attached to the bottom hole assembly and does not rotate during drilling. The apparatus and methods raise at least a portion of the pipe string in the deviated borehole to remove cuttings from underneath the pipe string portion.

Abstract: A method to clean the wellbore and the near wellbore formation adjacent to the wellbore of the gas bearing formation adjacent to the production zone of the wellbore. The method includes the steps of injecting a treatment liquid containing from 84.5 to 100% of liquid carbon dioxide, 0 to 15% of an alcohol, and 0 to 0.5% of a surfactant into the well in a predetermined quantity and maintaining the pressure of the treatment liquid in the near wellbore formation of the gas bearing formation below the fracturing pressure of the formation, releasing the pressure on the wellbore and allowing the liquid CO2 to vaporize and other materials to blow out of the well.

Abstract: A method for cleaning a plugged gravel pack in a subterranean wellbore is provided. The method comprises the steps of using a pressure pulsating jet and a tangential vortex to deliver a pressure pulsating treatment fluid into the gravel pack wherein soluble plugging materials in the gravel pack are dissolved by the treatment fluid and insoluble plugging materials are moved through the gravel pack and circulated out of the wellbore. The treatment fluid is driven into the gravel pack to dissolve soluble fines and displace insoluble fines from the interstitial pore spaces of the gravel pack.

Abstract: A storable cement system comprises a suspending agent, a cement spacer and water. The composition may further optional contain a surfactant and/or an organic solvent and/or a weighting material. The suspending agent is preferably a carrageenan or scleroglucan. The cement system may be stored for an extended period of time prior to being interposed between a cement slurry and a drilling fluid. As such, the aqueous cement system may be made off-site and used when desired for preventing contact between non-compatible hydrocarbonaceous and aqueous fluids.

Abstract: A fluid flow switching device for a drill string comprises a tubular member having a port (4). A sleeve member is slidable within the tublar member between a first position in which a port (3) thereof is in alignment with the port (4) and a second position in which the port (4) is obstructed. A plurality of fingers are connected to the sleeve member (2). Each finger defines one segment of a closure member, that is closed when the fingers are pivoted inwardly and open when the fingers are pivoted outwardly. An operating surface is positioned within the tubular member, and the fingers are axially slidable thereover as the sleeve member is moved between the first and second positions to close and open the segmented closure.

Abstract: The present invention provides methods and compositions for treating subterranean zones penetrated by well bores utilizing environmentally safe viscous fluids. A method of the invention comprises the following steps. A viscous treating fluid composition is provided comprised of water, a viscosity increasing polymer and a water soluble delayed polymer breaker that comprises a mixture of sodium perborate tetrahydrate and a solubility increasing boron complex or ester forming compound. The viscous treating fluid composition is introduced into the subterranean zone wherein the viscous treating fluid is allowed to break into a thin fluid of reduced viscosity.

Abstract: The present invention generally relates to a method for recovering productivity of an existing well. First, an assembly is inserted into a wellbore, the assembly includes a tubular member for transporting drilling fluid downhole and an under-reamer disposed at the end of the tubular member. Upon insertion of the assembly, an annulus is created between the assembly and the wellbore. Next, the assembly is positioned near a zone of interest and drilling fluid is pumped down the tubular member. The drilling fluid is used to create an underbalanced condition where a hydrostatic pressure in the annulus is below a zone of interest pressure. The under-reamer is activated to enlarge the wellbore diameter and remove a layer of skin for a predetermined length. During the under-reaming operation, the hydrostatic pressure is maintained below the zone of interest pressure, thereby allowing wellbore fluid to migrate up the annulus and out of the wellbore.

Abstract: A method of cleaning debris from a string of production tubing in a well enables removal without pulling the string of rods that extend through the tubing. A rotary pump is suspended to a lower end of the tubing for pumping well fluid through the tubing to a wellhead at the surface. A motor assembly at the surface rotates the rods to drive the pump. A closure member is placed on a lower end of an elastomeric hose that will open when a selected level of internal fluid pressure is applied. The operator applies internal pressure to the hose at a pressure less than the selected level to increase rigidity of the hose. The operator inserts the hose through a port in a sidewall of the wellhead, the hose deflecting downward and into the tubing. At a desired point, the operator increases the internal pressure in the hose to open the closure member, then discharges a cleansing fluid into the tubing, which flows back up the tubing along with debris.

Abstract: A manifold device connects in series between the wellhead and the outer casing of a well for providing access to the outer casing of the well without removing the wellhead. The device includes a tubular body for receiving the tubing string of the well therethrough. Plural access passages are formed in the tubular body to extend generally in the longitudinal direction of the body between an external end which is spaced radially from the hollow interior of the tubular body and an internal end converging in communication with the hollow interior at the bottom end of the manifold device. Well servicing tools can be inserted into the casing annulus defined between the outer casing and the tubing string of the well through one of the access passages formed in the tubular body of the manifold device.

Abstract: The present invention provides methods of stabilizing subterranean formations and methods of reducing the production of particulates from subterranean formations, which are useful in conjunction with subterranean formations surrounding wellbores and fractures. The methods comprise the steps of applying to a subterranean formation a combination aqueous liquid and surfactant preflush solution, an integrated consolidation fluid and an afterflush fluid and then waiting a chosen period of time.

Abstract: A system and method for restarting a downhole pump that has seized due to an accumulation of debris above the pump and around the pump intake. The system consists of a flexible annulus sealing element fitted on a joint of production tubing where the annulus seal can be activated by pumping fluid down the well annulus from surface. The tool includes tubing and check valve arrangements such that fluid from the well annulus above the flexible annulus sealing element can enter the production tubing immediately above the downhole pump and circulate debris back to surface as well as introduce fluid to the pump intake to mobilize debris accumulated at the pump intake.

Abstract: The current invention provides methods of using and drilling and servicing fluid compositions for depositing and removing filter cake from the walls of a well bore. The compositions make use of particulate solid bridging agent comprised of a salt of an organic acid. The bridging particles are dissolvable by a clean-up solution comprised of a mild solvent that is less corrosive than the conventional strong mineral acids used for this purpose.

Abstract: A casing scraper comprises a generally cylindrical body (1) adapted for connection at one end to a drill string, having a plurality of scraping or scouring elements (2) disposed around the outer surface thereof. A pipe (6) extends through the cylindrical body (1). One end of the pipe (6) is adapted for connection to a source of cleaning fluid and the other end is connected to a tail pipe (7). The tail pipe (7) has at least one opening (8) in it through which cleaning fluid may be circulated into the well casing. The casing scraper further comprises filtration structure (4) located above the openings (8) in the tail pipe (7) and remotely operable structure (9, 10) for selectively directing the flow of cleaning fluid from passing outside the filtration structure (4) to passing through the filtration structure (4).

Abstract: A well servicing apparatus and method which facilitates servicing of a well without removal of the wellhead equipment, production tubing, or pump drive rod. One embodiment of the invention allows flexible tubing to be inserted into the production tubing string of a well. Fluid can then be pumped through the flexible tubing for purposes such as removing sand from the production tubing string. Another embodiment of the invention allows flexible tubing to be inserted into either the production tubing string or well casing or both. Fluid can then be pumped through the flexible tubing for purposes such as removing sand from either the production tubing string or well casing.

Abstract: Compositions and methods for treating systems, especially oil and/or gas wells, characterized by metal sulfide deposits are provided. Compositions according to the invention generally comprise a thioacid, an amine salt, and a diphosphonic acid. Methods according to the invention may comprise introducing such composition into a system characterized by metal sulfide deposits, or alternatively, introducing into the system individual quantities of the composition components.

Abstract: A well treatment tool is installed along the sucker rod string of a well, within the surrounding production tube string. The tool provides for the distribution of a treatment fluid (solvent, etc.) within the fluid being pumped or flowing from the well. The tool receives treatment fluid through the hollow sucker rod string, and distributes the fluid through a valve which is set at a predetermined pressure. When the treatment fluid pumped down the sucker rod string from the surface exceeds the predetermined opening pressure of the valve, the treatment fluid is distributed into the production tube string through one or more passages in the tool. The present tool may be used simultaneously with well production, with fluid (oil, etc.) rising up the production tube string, carrying the treatment fluid therewith. The treatment fluid is thus distributed throughout the local fluid processing system, including pipelines from the well, any initial treatment operations, and any storage tanks.

Abstract: Methods of drilling and completing open hole well bores and methods of removing filter cake comprised of a gelling agent and calcium carbonate are provided. A method of the invention for removing filter cake comprised of a gelling agent and calcium carbonate from the walls of an open hole well bore is basically comprised of the steps of contacting the filter cake with a delayed clean-up solution comprised of water and a formate ester and removing the clean-up solution from the well bore.

Abstract: The pressure reading tool includes a housing with an interior chamber and an orifice extending from the chamber to the exterior of the housing. A pulse member with a magnetostrictive ring and an excitation source are disposed within the chamber to produce a highly agitated fluid discharge through the orifice. The magnetostrictive ring, chamber volume, and orifice cooperate to induce Helmholtz resonance frequencies in the fluid in the chamber to thereby enhance the agitation of the fluid discharge. A sheathing encapsulates the pulse member to protect it from contact with the fluid. A dampening element is also interposed between the pulse member and housing to isolate vibration.

Abstract: Present invention relates to high brine carrier fluid, said carrier fluid selected from the group consisting of organic acids, organic acid salts, inorganic salts and combination of one or more organic acids or organic acid salts, a co-surfactant and an amount of a zwitterionic surfactant. The invention also relates to methods of treating a subterranean wellbore, including drilling, hydraulic fracturing, gravel placement, scale removing, mud cake removing, using said high brine carrier fluid.

Abstract: A tubular body or mandrel incorporated into a string of tubular pipe, on which first and second swab cups and first and second metal brushes and a casing scraper are mounted, is run into a cased earth borehole to displace a first fluid in the borehole, usually a drilling fluid, with a second fluid, usually either a completion fluid or a workover fluid. In a first embodiment, reverse circulation, in which the second fluid is pumped into the borehole annulus above the swab cups and/or the metal brushes, and in which the first fluid is thereby pumped back towards the earth's surface through the interior of the string of tubular pipe, causes displacement of the first fluid merely by lowering the string of pipe while pumping the second fluid into the borehole annulus.

Abstract: A retrievable pig apparatus having a substantially cylindrical body portion, the body portion having a central flow bore therethrough, and secured to coiled tubing, including a central fluid flow bore in fluid communication with the interior bore of the coiled tubing; a plurality of flow bores spaced equally apart within the body, with the flow bores allowing fluid flow to be injected at a certain predetermined pressure through the flow bores, so as to be emitted on the front end of the pig for defining a high pressure spray of fluid or the like material to break up blockages of debris in the pipeline, such as paraffin or the like; the debris retrieved through the central bore back into the coiled tubing to be stored in a tank or the like on the surface.

Abstract: The present invention provides an apparatus and a method for removing undesirable material from a well bore in a hydrocarbon formation with minimum damage to the formation. The apparatus comprises a concentric tubing string, said concentric tubing string further comprising an inner tube means having an inner annulus therethrough and an outer tube means forming an outer annulus between said outer tube means and said inner tube means, means for introducing into said well bore a pressurized clean out medium through one of the said inner annulus and outer annulus, and means for removing said material and clean out medium through the other of the said inner annulus and said outer annulus to the surface of said well bore. In a preferred embodiment, the introducing means comprises a discharge compressor or mud pump and the removing means comprises a suctioning compressor.

Abstract: A method and apparatus for improving reservoir communication includes, in one arrangement, causing creation of tunnels in surrounding formation of a well interval, and applying treatment fluid to the tunnels. A local transient underbalance condition is created in the well interval after creation of the tunnels in the formation and application of the treatment fluids.

Abstract: A separation barrier for placement in an open well bore or casing, to prevent migration of cement slurry downwardly into the drilling fluid, facilitating the placement of a cement plug to segregate a well bore into uphole and downhole portions. The barrier has an annular seal which facilitates pumping the barrier downhole through a work string to a desired location. The separation barrier also has a plurality of flexible elongated elements which expand outwardly when the barrier exits the work string. The elongated elements are closely spaced to prevent migration or contamination of cement slurry therebetween. The barrier can also have a shearable landing ring for providing positive indication of placement of the barrier at the desired location.

Abstract: A method and apparatus for fluid treatment of a selected interval of a well and then cleaning the selected interval and the apparatus of treatment residue. An Out/In straddle tool is run into the well to treatment depth on fluid supplying tubing and has upper and lower packers that establish sealing with the casing and define an annular interval between the packers and between the tool and casing. Fluid, such as fracturing fluid, is pumped through the tubing to the tool and is diverted through an Out port of the tool into an upper portion of the annular interval. Fluid then flows from a lower portion of the annular interval through an In port below the Out port and at low flow rate is dumped into the casing through a pressure responsive dump valve. The Out port and In port are located to accomplish cleaning of residue from the packers.

Abstract: A borehole wall cleaning apparatus and method for obtaining an improved seal between a fluid sampling device and a portion of the borehole wall. Clean drilling fluid is pumped into a drilling tool using a mud pump. A fluid diverter in the tool diverts all or part of the clean drilling fluid through a port to clear a portion of a borehole wall. A sealing pad is moved against the clean portion. A sampling port is exposed to the sealed portion for sampling and/or testing fluid from the formation.

Abstract: A well completion method performed in a single trip into a well includes inserting a service tool into the well to a desired location; gravel packing the well; and circulating fluids within the wellbore through the service tool to dislodge and remove filter cake residue. A method of completing a subterranean well performed in a single trip into a wellbore includes running a service tool into the well, the service tool defining multiple, selectable flow paths; gravel packing the well; selecting a different flow path of the service tool; removing a filter cake from the wellbore by circulating a fluid through the service tool; spotting specially fluids within the wellbore at desired locations; and removing the service string from the well.

Abstract: A method of removing formation damage through the controlled injection of fluids into the formation, followed by a controlled sudden release of pressure in the formation, an under-balanced surge, which causes fluid and damaging materials to flow back into the well bore. This method is most effective when repeated more than once.

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 a phosphonic acid, alkali or alkaline earth metal phosphonic acid salts, or mixtures thereof. 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: The present invention provides a simple debris removal apparatus for use in a wellbore. In one aspect of the invention a modular, interchangeable venturi is provided which can be retrofit into an existing debris bailer having a filter and a debris collection container. In another aspect of the invention, a venturi is utilized to create a negative pressure in a wellbore sufficient to actuate a retrieval tool for a downhole device. In yet another aspect of the invention, a combination tool is provided which can evacuate debris in a wellbore, thereby uncovering a downhole device which can then be removed in a single trip. In yet another aspect of the invention, a debris removal apparatus is provided with a method for the apparatus in a wellbore on coiled tubing.

Abstract: Improved methods of generating gas in and foaming aqueous well fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining with an alkaline aqueous well fluid one or more gas generating chemicals and a mixture of foaming and foaming stabilizing surfactants so that the gas generating chemical or chemicals react with the alkaline aqueous well fluid and gas and foam are formed in the well fluid while it is being pumped, and then pumping the well fluid into the subterranean zone.

Abstract: A method of the preparation and utilization of polymerized alpha-hydroxycarboxylic-acid-coated proppants for gravel pack and removal of filter cake that was deposited by reservoir drilling fluid. In a preferred example, polyglycolic-acid-coated sand is used to replace conventional gravel pack sand typically used for gravel packing. Under downhole conditions, the acidic by-product generated from the hydration of polyglycolic-acid-coated sand can break down acid-soluble and/or acid-breakable components embedded in the filter cake. This reaction enhances the filter cake removal and the flow of hydrocarbon from the producing formation. The polyglycolic-acid-coated sand may be produced by polymerizing a glycolic acid with a natural or synthetic proppant like 20-40 mesh commercial sand, at temperatures of about 210° F. or higher.

Abstract: A system for cleaning of vertical risers at floating drilling rigs, which comprises the following main components: a high-pressure pump (16); an umbilical hose (26) comprised of a hydraulic tubing and an electric cable, a cable winch unit (18) and an internal flushing device (20). The flushing device comprises a number of spring loaded centring wheels (32) around the body (31), one or more rotary high-pressure jets (34) in the body (31), collecting means (38) for larger particles at the lower section of the body (31) and a camera (40) fitted to the underside of the tool (30).

Abstract: A method and apparatus for producing fluid cavitation is provided. For a given channel cross-section of a pressure line, the flow is accelerated so as to reach a speed at which Re>Recr, where Re is the Reynolds number and Recr is the critical Reynolds number; the flow is then interrupted for a time less than half of the phase of the hydraulic shock. The device for cavitation of fluid flow is mounted in the channel of a pressure line and includes a cavitator which has the form of a working body placed in the casing and can move radially inside the line and, to a limited extent, along the axis of the line. The maximum cross-section surface of the working body in a plane perpendicular co the axis of the line is more than 0.8 of the passage of the line but not equal to it.

Abstract: A method of removing a gravel packed screen to reach another zone is described. The method involves a bottom hole assembly comprising an isolation device for the screen and a tool to latch on to it. A perforating gun is shot off to put holes in the screen to allow gravel to come through. A flow through a reversing valve is initiated to urge the gravel into the newly perforated screen while a vibrator shakes the screen and stimulates gravel flow through the screen. Alternatively, the screen is not isolated and a reverse circulation from the surface in conjunction with vibration urges the gravel to flow through the screen and out through the tubing supporting the bottom hole assembly.

Abstract: A method for treating an underground reservoir, which method comprises introducing into the reservoir a treatment fluid comprising, dissolved or dispersed in water, an ester and a non-enzyme catalyst capable of increasing the rate of hydrolysis of the ester, such that the ester hydrolyses to produce an organic acid to dissolve acid soluble material present within the reservoir.

Abstract: A method for removing filter cake from a subterranean borehole comprising drilling the borehole with a drilling fluid that includes additives to form a filter cake having an oxidation-degradable component, preferably a polysaccharide. The filter cake is contacted with a clear brine containing a mixture of a persulfate salt in a variable density brine to degrade the polymers within the filter cake. The persulfate mixture breaks down the filter cake in well bores having temperatures ranging from about 65° F. to 165° F. Concentration of the persulfate sets the pace of the reaction.

Abstract: A method of cleaning a casing-lined borehole comprises the steps of: circulating fluid in the borehole to entrain material in the circulating fluid; separating the entrained material from the fluid within the borehole; and then removing the separated material from the borehole.

Abstract: A device for cleaning an inner pipe which comprises a nozzle head comprised of a feed borehole axially disposed therein, at least two rotation nozzles communicating with the feed borehole, at least two cleaning nozzles communicating with the feed borehole and a shaft. A rinsing nozzle communicates with the feed borehole and extends upwardly at an angle from the longitudinal axis of the feed borehole. The shaft is received in an outer sleeve whereby when the device is inserted into an inner pipe and a medium is flowed through the borehole and out of the rotation nozzles a force is generated when the medium emerging from the rotation nozzles contacts the wall of the inner pipe which force causes the nozzle head to rotate.

Abstract: An apparatus for cleaning a natural gas well bore, including a master valve capping the well bore, the master valve supporting a blowout preventor and injector head. The master valve is interconnected with a pressure vessel through a first control valve and the pressure vessel is interconnected with a compressor and with a gas pipeline through a second and a third control valves. The compressor provides compressed natural gas from the pressure vessel to the well bore through the injector head and the master valve via a tubing reel inserted into the well bore.

Abstract: A production tubing joint is disclosed for a well comprising a barrel forming an upper tubing section and connected to the tubing hanger, a tubing connector within the barrel having a lower end connected to a lower tubing section of the production tubing string, a lower locking means having a first lower lock component secured to the barrel and a second lower lock component secured to the tubing connector and selectively engageable with the first lower lock component for suspending the tubing connector and the lower tubing section from the barrel, an adapter bar for connection to a rod string, and an upper locking means having a first upper lock component secured to the tubing connector and a second upper lock component secured to the adapter bar and selectively engageable with the first upper lock component.

Abstract: A system and method for removing particles from a well bore penetrating a possible hydrocarbon producing formation, according to which drilling fluid is mixed with a weighted material, and the mixture is introduced into a well bore so that the mixture scours any particles accumulated in the well bore. A well-completion fluid is introduced into the well bore that dissolves the weighted material.

Abstract: Well completion foamed spacer fluids and methods of using the foamed spacer fluids are provided. A method of the invention for displacing a first fluid from a well bore with an incompatible second fluid comprises the following steps. A foamed spacer fluid is placed between the first and second fluids to separate the first and second fluids and to remove the first fluid from the walls of the well bore. Thereafter, the first fluid and the foamed spacer fluid are displaced from the well bore with the second fluid.

Abstract: An apparatus for cleaning a natural gas well bore, including a master valve capping the well bore, the master valve supporting a blowout preventor and injector head. The master valve is interconnected with a pressure vessel through a first control valve and the pressure vessel is interconnected with a compressor and with a gas pipeline through a second and a third control valves. The compressor provides compressed natural gas from the pressure vessel to the well bore through the injector head and the master valve via a tubing reel inserted into the well bore.

Abstract: The present invention provides a simple debris removal apparatus for use in a wellbore. In one aspect of the invention a modular, interchangeable venturi is provided which can be retrofit into an existing debris bailer having a filter and a debris collection container. In another aspect of the invention, a venturi is utilized to create a negative pressure in a wellbore sufficient to actuate a retrieval tool for a downhole device. In yet another aspect of the invention, a combination tool is provided which can evacuate debris in a wellbore, thereby uncovering a downhole device which can then be removed in a single trip. In yet another aspect of the invention, a debris removal apparatus is provided with a method for utilizing the apparatus in a wellbore on coiled tubing.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of vanadium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation.

Abstract: A retrievable pig apparatus having a substantially cylindrical body portion, the body portion having a central flow bore therethrough, and secured to coiled tubing, including a central fluid flow bore in fluid communication with the interior bore of the coiled tubing; a plurality of flow bores spaced equally apart within the body, with the flow bores allowing fluid flow to be injected at a certain predetermined pressure through the flow bores, so as to be emitted on the front end of the pig for defining a high pressure spray of fluid or the like material to break up blockages of debris in the pipeline, such as paraffin or the like; the debris retrieved through the central bore back into the coiled tubing to be stored in a tank or the like on the surface.

Abstract: A method and apparatus for delivering treatment chemicals to an oil and gas well. A flush pump siphons flush from the production line of a producing well and draws in a predetermined amount of treatment chemical into the siphoned flush and then discharges the combination into the well.

Abstract: Method and Apparatus for gravel packing, cleaning and lifting wells, including through tubing methods, circulating well fluids through a coiled tubing string having a leak protection barrier operable for at least a portion of the string passing above a wellhead and employing a circulating and release sub.

Abstract: A method of gravel packing a wellbore which has at least one aperture therein that provides a fluid flow path between the wellbore and an adjacent subterranean formation. At least a part of the formation adjacent to the open hole has a filter cake coated thereon that comprises a water and oil emulsion. The method of gravel packing comprises injecting into the wellbore a gravel pack composition that comprises gravel and a carrier fluid. The carrier fluid comprises an aqueous liquid having a pH that is outside the range at which the filter cake emulsion is stable. The aqueous liquid is present in an amount effective to invert the water in oil emulsion in the filter cake when the carrier fluid comes into contact with the filter cake. As a result, gravel is deposited at or adjacent to the aperture in the wellbore and some of the filter cake is removed.