Abstract: A method of cleaning walls of a wellbore that includes contacting the walls with a cleaning fluid, the cleaning fluid comprising: a base fluid comprising a blend of a base oil and at least one of a mutual solvent or a terpene; and an alkyl glycoside is disclosed herein.

Abstract: The invention provides a device for cleaning a wellbore, comprising a tubular section, a helical scratcher mounted thereof wherein said helical scratcher contains flexible wires characterized in that the helical scratcher is able to rotate axially to tubular section when a fluid flows axially to tubular section. Alternatively, the invention provides the method to clean a wellbore wall of a well, said method comprises the steps of: incorporating a device as previously described into the wellbore; moving the device in the well and allowing the fluid flowing axially to the wellbore wall to rotate the scratcher; removing deposit at wellbore wall; leaving a cleaned wellbore wall.

Abstract: A reverse torque drive system for a wellhead has a hydraulic pump having an inlet and an outlet, and a hydraulic motor having a first port and a second port. There is a valve body having a first position that connects the outlet of the hydraulic motor to the first port and the second port to the inlet, and a second position that connects the outlet to the second port and the first port to the inlet. One or more sensors are connected to measure a condition, and a controller moves the valve body from the first position to the second position upon the sensor sensing a predetermined condition.

Abstract: Disclosed is a maintenance device for an elongate, tubular hollow member (2) designed to conduct a fluid. Said maintenance device comprises a sealing mechanism (4) which is to seal a working zone (9) relative to surroundings (30) of the hollow member (2) and can be moved in one direction along the hollow member (2). A side of the sealing mechanism (4) that faces the hollow member (2) forms an at least partially curved surface and can be moved in the longitudinal direction of the hollow member (2), especially in order to be placed in the sealing position. A method for servicing an elongate, tubular hollow member (2) is also claimed.

Abstract: The present invention includes compositions and methods of treating a hydrocarbon-bearing formation, the formation having at least one fracture, by contacting the fracture with a composition that includes a solvent and a nonionic fluorinated polymeric surfactant, wherein the composition interacts with at least a portion of the proppants in the fracture.

Abstract: An assembly for removing debris and/or conducting a wellbore operation may include a mandrel, a sliding sleeve rotationally coupled to the mandrel, and a flushing sleeve coupled to the sliding sleeve. A releasable connection may temporarily prevent axial movement between the sliding sleeve and the mandrel. A downhole tool may be coupled to the mandrel to conduct the wellbore operation. The flushing sleeve may be hydraulically actuated to an extended position ahead of the downhole tool. A method of removing debris from a wellbore and conducting a wellbore operation may include lowering an assembly into the wellbore, supplying pressurized fluid into the wellbore using the assembly to remove debris from the wellbore, and moving a downhole tool to a position where at least a portion of the downhole tool is disposed outside of the assembly to conduct the wellbore operation.

Abstract: The invention consists in loading a chemical wash fluid with solid particles to enhance annulus cleanup prior to placing cement slurries (or during the completion phase). The presence of solid particles in a low-viscosity fluid will induce an abrasive cleanup of all soft material present in the annulus in particular gelled mud and mud cake. There is no need for special hardware and no harm to metallic parts. The particles have a size of at least 100 microns and a density ranging from 0.1 to 2g/cm3.

Abstract: A method and a device for removing sediment or other undesired material (28) from a cavity (24) in a petroleum well (2) in which a tool (30) is moved down into the petroleum well (2). The method including placing a detonable charge (34) in the tool (30) and detonating the charge (34) after the tool (30) has been positioned in the petroleum well (2).

Abstract: A method of solubilizing/removing cellulose or chemically-modified cellulosic polymers utilized in subterranean drilling operations such as fracturing. The method involves introducing a deep eutectic solvent (DES) into a subterranean region. Deep eutectic solvents useful as cellulose solvents include quaternary ammonium compounds, including choline chloride and chlorcholine chloride, reacted with a compound selected from amides, amines, carboxylic acids alcohols, and metal halides. The DES material can be pumped downhole after fracturing operations to remove cellulosic material used, for example, to thicken fracturing fluid which is left behind in the created fractures, on the face of the formation, along the wellbore, or elsewhere within the subterranean region. The DES can be used alone or in a sequential treatment protocol, whereby the DES is introduced into the subterranean region, followed by post-treatment introduction of water, caustic, acid or anhydride into the subterranean as a flush.

Abstract: A fluid loss control method uses a fluid loss control pill in a well in advance of a completion operation. An embodiment of the fluid loss control pill comprises polyester solids that are hydrolysable and can exhibit plastic deformation at formation conditions. An embodiment of the method comprises spotting the fluid loss control pill in the well adjacent to a formation to form a filtercake to inhibit fluid entry from the well into the formation, performing a completion operation comprising contacting the filtercake with overbalanced wellbore fluid, and degrading the filtercake wherein the polyester particles are hydrolyzed to remove formation damage.

Abstract: A carrier assembly having at least one sealing cup, a fluid bypass and adjustable wash nozzles, as well as a spear assembly having a central through bore, are attached to the distal end of a length of continuous tubing and inserted in to the flow bore of a pipeline. Fluid is pumped through the annular space between the carrier assembly and the pipeline, providing motive force for advancing the carrier assembly within the pipeline. Fluid can bypass the carrier assembly, enter the central bore of the spear assembly, and return to the surface through the central bore of the continuous tubing. A stuck pig or other obstruction is speared, and thereafter retrieved from the pipeline on the continuous tubing.

Abstract: A method of flushing a wellbore fluid from a downhole tool containing a bearing package includes pumping hydraulic oil through at least one of a hydraulic inlet line and at least one of a pneumatic inlet line connected to the main housing and into an annulus formed between the bearing package and a main housing of the downhole tool, wherein the hydraulic oil replaces the wellbore fluid in the annulus, removing the wellbore fluid from the annulus through at least one hydraulic outlet line and at least one pneumatic outlet line connected to the main housing, pumping air through the at least one pneumatic inlet line connected to the main housing and removing the hydraulic oil from the at least one pneumatic inlet line connected to the main housing, and removing the hydraulic oil through at least one pneumatic outlet line connected to the main housing.

Abstract: In some embodiments, apparatus useful for cleaning at least part of the interior surface of a generally cylindrically-shaped member disposed in a subterranean well includes a housing and a plurality of retractable mill blades supported on the housing and movable from an initial retracted position to an extended position and thereafter to a final retracted position.

Abstract: A method of cleaning a wellbore drilled with an oil-based drilling fluid that forms an oil-based filter cake where the method includes: emplacing a breaker fluid into the wellbore, the breaker fluid comprising: a water-miscible non-aqueous fluid; at least one weighting salt; and at least one breaking agent; and shutting in the well for a period of time sufficient to initiate breaking of the oil-based filter cake is disclosed.

Abstract: A downhole oilfield completion method comprises determining a surge profile for a wellbore and assembling a downhole completion tool having an interior surge volume and comprising a surge attenuation system operable to reduce a surge of the downhole completion tool based at least in part on the surge profile. The method also comprises running the downhole completion tool into the wellbore and surging the wellbore by admitting wellbore fluid into the interior surge volume, the surge reduced at least in part by the surge attenuation system.

Abstract: A downhole cleaning tool comprising: a substantially cylindrical body; at least one cleaning member extending from the cylindrical body and being movable between a retracted position and an active position in which the cleaning member is positioned to clean an internal surface of the well bore; and switching means adapted to receive a force applied in a first direction and responsively move the at least one cleaning member from the retracted position to the active position.

Abstract: A method for removing preexisting filtercake from a portion of a subterranean formation penetrated by a wellbore is carried out by providing water-degradable particles formed from a solid polymeric acid precursor material that is capable of a degrading to acid for reacting with materials of the filtercake. A slurry is formed from the particles with a carrier fluid. The slurry of particles is introduced into the formation through the wellbore and allowed to degrade to form acid, whereby the formed acid facilitates decomposition of preexisting filtercake material. In certain applications, the water-degradable particles may also be used in combination with non-water-degradable particles, which may be used for forming a gravel pack. The water-degradable particles may also be used to reduce fluid loss temporarily to areas of the formation immediately surrounding the wellbore.

Abstract: An acid treatment composition is provided including a corrosion inhibitor and an optional corrosion inhibitor intensifier in an acidic solution. More specifically, the composition includes an anionic surfactant. Methods for treating wells with these acid treatment compositions are also provided that help control corrosion of the steel used in the wells during the acid treatment.

Abstract: A gas insertion tool for cleaning a well bore is connected to the down hole end of a fluid supply tubing inserted through a positioning string within a well bore. Fluid pressure within the string pushes the well tool therethrough pulling the fluid supply line and then exiting the well string within the well bore adjacent its termination. The positioning string is retrieved leaving the tool wedgeably secured within the well bore for dispensing pressurized fluid within the well bore dislodging fluid and trapped foreign material within the horizontal leg of the well bore.

Abstract: An underbalanced perforating system is disclosed for use in openhole completions to maximize the wellbore and matrix cleanup efficiency, to connect natural fracture patterns, and/or to enable application of new drilling fluid technology in difficult subsurface environments. The perforating system can be used for any hydrocarbon bearing formations with any lithology.

Abstract: The amount of crystallized salt in an oil and/or gas well may be minimized or reduced by use of a fructan, such as inulin, or a derivative as a salt block inhibitor. A preferred salt inhibitor is the salt of carboxyalkyl inulin such as a sodium salt of carboxymethyl inulin. The salt block inhibitor may be adsorbed onto a water-insoluble adsorbent.

Abstract: A method of purging fluids from a gas well wellbore having a tubing string and casing in fluid communication by introducing pressurized methane gas into either the tubing string or casing of the wellbore at the well surface to displace the fluids out of the wellbore through the counterpart casing or tubing string of the wellbore, and a system for storage and delivery of pressurized methane gas in which an assembly of aligned gas cylinders, each cylinder having a valve at one end, the valves contained within a manifold at one end of the assembly, the manifold having a single valve to control flow of the gas into and out of the cylinders of the assembly for delivery of the pressurized gas into a pipeline or wellbore.

Abstract: A method for using or removing unused rock debris from a bored passageway through subterranean strata using at least one rock breaking apparatus engaged with a conduit string and placed within the subterranean passageway proximal region, using a member adapted to increase the volume of reduced particle size rock debris generated by increasing the frequency of impact and associated breakage of the rock debris inventory, per revolution of the conduit string and/or per volume of fluid slurry circulated. The used volume of rock debris inventory coats the unlined strata wall of said passageway to inhibit strata fracture initiation or propagation, and the unused rock debris inventory is urged from the passageway at an increased rate by the associated reduction in fluid slurry suspension or velocities needed to urge the rock debris through the unlined strata passageway of improved pressure integrity from inhibiting said initiation or propagation of strata fractures.

Abstract: Methods are given for making scale inhibitors, that were previously incompatible with fluids containing fluoride ion, compatible with fluids containing fluoride ion. Examples of such scale inhibitors include phosphonates and phosphino-polycarboxylates. The method is replacing alkali metal and alkaline earth metal cations, present in salts or bases, or as counter ions of the scale inhibitors, with hydrogen or ammonium ions. Methods of inhibiting scale formation and of dissolving scales are also given.

Abstract: A method for cleaning and/or altering an inside surface and shape of a tubular is disclosed. The method includes placing a surface finishing tool in the tubular, energizing the surface finishing tool, and causing extendable assemblies therein to extend radially to contact an inside diameter of the tubular. Moving the surface finishing tool axially and/or rotationally while the extended members are in contact with the inside diameter of the tubular cleans debris from the inside surface of the tubular. In another aspect of the invention, the tool burnishes the inside diameter of the tubular, thereby altering the surface characteristics and rounding the tubular.

Abstract: Generating heat within a combination solvent/acid system removes undesirable deposits from petroleum reservoir formations (especially the near well-bore region), oilfield equipment, and petroleum processing equipment. An exothermic reaction occurs between the solvent and the acid and the heat evolved helps remove organic solid deposits. The acids may include organic acid compounds, such as sulfonic acids, sulfuric acid and nitric acid. The solvents may include terpene- and terpene-derivative-containing solvents, including, but not necessarily limited to, limonene, pinene, dipentene, myrcene, turpentines and compounds having at least one double bond, such as methyl furan, dienes, styrene, vinyl acetate and the like. The exothermic reaction produces a great amount of heat, and together with using certain acids and solvents already known as effective to remove paraffin and asphaltene deposition, removing such deposits is improved.

Abstract: An apparatus and method is provided for stripping solids and fluids from a string used in the drilling or servicing of a well when the string is removed from the well. The apparatus can comprise two or more pivotally connected arcuate body portions that can be enclosed around the string in a clamshell fashion. The apparatus can further comprise a seal disposed therein to provide a toroidal sealing member around the string when the apparatus encloses the string. A quick release latch mechanism is provided on the apparatus for easy and quick installation on, and removal from, the string. Handles on the apparatus allow personnel to hold the apparatus in a stationary position as the string passes through the apparatus when being raised from the well. In so doing, the sealing member strips solids and fluids from the string.

Abstract: A technique utilizes a tool to selectively shift flow control devices in a variety of well applications. In one application, the tool is delivered downhole via coiled tubing to selectively deliver treatment fluid and shift valves in a combined well treatment and sand control well system. The tool also can be used to carry a jetting device that can be employed to deliver a non-solids fluid to a desired region of a wellbore.

Abstract: A method for removing drilling damage from a formation in a wellbore that has not been produced includes injecting a chemical-acting cleanup fluid and contacting it with a filtercake on a face of a formation of interest for a period of time sufficient to loosen some of the solids embedded in the filtercake. The method further includes circulating a solids removal fluid at a high rate through the wellbore across the face of the formation of interest, the solids removal fluid including a viscosifier, and positioning a second treatment fluid having a fluid loss control pill in the wellbore at the formation of interest. The method further includes degrading particles of the fluid loss control pill and degrading remaining bridging agent from the drilling fluid.

Abstract: A method of removing clay compounded on drilling equipment in a well that includes contacting the drilling equipment with a treatment fluid comprising an oxidizing agent.

Abstract: Sliding sleeve mechanisms including protective sheaths for debris protection are disclosed. Protective sheaths can be formed from materials such as composites, metal, foil, rubber, plastic, glass, ceramic, wire mesh, tape, etc. The protective sheaths can be substantially cylindrical shells (having one or more pieces), plugs in the flow ports, and/or tape or wire wrappings. The protective sheaths can be retained by recesses in the sliding sleeve or mechanical fasteners such as screws, pins, rivets, snap rings, bands, and buckles. The protective sheath can be outside or inside the sliding sleeve. The protective sheath can protect the sliding sleeve from debris by retaining grease that has been packed into the sliding sleeve for that purpose or positively preventing entry of debris into the sliding sleeve. The protective sheath can be cleared by permitting fluid flow through the sliding sleeve, which can act to destroy and/or wash away the protective sheath.

Abstract: A tool (2) for washing a wellbore or hollow tubular has a longitudinal axis and comprises one or more elongate nozzles (7) for ejecting fluid generally radially from the tool. The or each nozzle extends circumferentially around the tool so as to provide a continuous stationary jet of fluid. Preferably the nozzles collectively provide 360° around the tool.

Abstract: Apparatus and methods for performing downhole operations. The apparatus can include a sealing mechanism having an inner bore formed therethrough; a check valve adjacent the sealing mechanism; a circulation device adjacent the check valve; and a rotatable nozzle adjacent the circulation device. The circulation device can include a first tubular member having a radial hole formed therethrough, and a second tubular member disposed about at least a portion of the first tubular member. The second tubular member can also have a radial hole formed therethrough, and the second tubular member can be adapted to longitudinally move about the first tubular member from a first position to a second position.

Abstract: A wellbore fluid that includes an aqueous base fluid; a chelating agent; and at least one enzyme, wherein the wellbore fluid has a pH of at least 6.5 is disclosed.

Abstract: A perforating gun and one or more volume-receiving surge canisters can be actuated at a time delay after perforation for creating a dynamic underbalance condition to aid in directing debris out of the perforations and fractures and into the wellbore. A timer and triggering device actuate one or more canisters in parallel or series after a pre-determined time delay or delays which can be related to wellbore conditions following perforation. Use of propellant-type perforating gun further benefits from favorable propellant burn conditions for forming perforations and followed thereafter by a perforation-cleaning underbalance pressure conditions characterized by one or more of an increased rate of change depression of the pressure in the adjacent annulus, a greater magnitude of pressure depression and a longer duration of underbalance.

Abstract: A method of acidizing and cleaning up a formation is disclosed, the formation being above 150 degrees C. The formation is treated with a mutual solvent system comprising a mutual solvent of oil and water, an aqueous acid, a corrosion inhibitor, and an iron control agent. In some embodiments, the iron control agent is present in an amount of less than 1% by weight of the mutual solvent system. In some embodiments, the corrosion inhibitor may be present in an amount of less than 10% by weight of the mutual solvent system. In some embodiments, the mutual solvent system further comprises an intensifier.

Abstract: An apparatus for borehole cleaning comprises a tubular conveyance extending from the surface into a borehole to a region to be cleaned, a motor mounted at the end of the tubular conveyance that in use is introduced into the borehole, a pump connected to the motor and having a nozzle, and a power cable extending trough the tubular conveyance from the surface to provide power to the motor, The pump is arranged such that, when positioned in the borehole and operated by the motor, the pump withdraws material from the borehole through the nozzle and pumps it into the tubular conveyance to the surface.

Abstract: A method of treating a subterranean formation penetrated by a wellbore of a well having iron-containing components is carried out by introducing a treatment fluid into the wellbore of the well. The treatment fluid is formed from an aqueous solution, a mineral acid, a viscoelastic surfactant gelling agent and corrosion inhibitor system containing at least one of an alkyl, alkenyl, alicyclic or aromatic substituted aliphatic ketone and aliphatic or aromatic aldehyde. The treatment fluid is substantially free of any formic acid or precursor formic acid. In certain embodiments, the corrosion inhibitor system comprises a mixture of at least one of an alkenyl phenone or ?,?-unsaturated aldehyde, an unsaturated ketone or unsaturated aldehyde other than the alkenyl phenone and ?,?-unsaturated aldehyde, a dispersing agent, an extender and an alcohol solvent. A corrosion inhibitor intensifier may also be used in certain embodiments, which may include a mixture of cuprous iodide and cuprous chloride.

Abstract: A downhole well cleaning tool adapted for connection between upper and lower sections of an elongate string includes a pump barrel having at least one fluid outlet proximate its upper end. A swab assembly is connected to a pump mandrel for reciprocation within the pump barrel to pump fluids upward to the outlet to draw fluid and debris into the lower string section and trap the debris. A lower portion of the swab mandrel is hollow and open at a lower end thereof with at least one conduit extending through a side wall of the swab mandrel to direct fluid laterally outward from the hollow lower portion against the side wall of the pump barrel during lowering into fluid to reduce debris build-up within the pump barrel. A wear bushing is mounted between the pump mandrel and barrel and a knuckle or swivel joint connects the swab and pump mandrels.

Abstract: A method for treating a subterranean wellbore. More specifically, a method for removing wellbore solids. A first, polymer containing fluid is placed in the solids bed. A second, viscosifying fluid is then placed into the solids bed thereby agitating the solids in the bed and causing the formation of a gel capsules when mixed with the biopolymer fluid. These gel capsules are capable of trapping or entraining the agitated solids. The gel capsules typically have a relatively high volume and a relatively low density, thereby making their removal from the wellbore easier.

Abstract: An integrated fluid filtration and recirculation system and method are provided for re-circulating and filtering fluid that is used in well cleaning operations. The system is incorporated within an enclosure, which is transportable, such as on a vehicle trailer. The system has power generation capability, thereby making the system capable of operating as a stand-alone unit. Chemicals may be infused into the filtered fluid from an integral chemical supply allowing the system to also function as a treatment facility for the fluid. The components of the system are arranged in a linear fashion that enables the system to maintain a minimum profile for transport upon a conventional trailer, yet the system provides enough room within the enclosure to allow operators to repair/inspect each of the system components. The enclosure may be climate controlled, and the enclosure may include removable panels for operation of the system in temperate conditions when climate control is unnecessary.

Abstract: A cuttings bed removal tool for use on a drill string in a well bore includes: a sub having a region of enlarged outer diameter over the string diameters indicated by its upper end connection and an indicator disposed downhole of the region of enlarged outer diameter and having at least one bypass port extending through the indicator to permit passage of fluid in an upward direction through the indicator.

Abstract: A cleaning apparatus for cleaning the inner surface of an oil or gas production tubing is disclosed. The cleaning apparatus includes a tubular body, one or more cleaning elements mounted on the outer surface of the body and an elastically deformable stabiliser. The elastically deformable stabiliser is rotatably mounted on the body to centralise the apparatus in the tubing whilst also allowing the body to pass though areas of reduced diameter in the production tubing. Preferably, there are a pair of spaced apart stabilisers having a web arrangement of spars with a flange at each end.

Abstract: Methods for cleaning out horizontal wellbores using coiled tubing are provided for use during downhole operations. A coiled tubing having a bottom hole assembly is deployed into a horizontal wellbore. Fluid is circulated down the annulus of the wellbore and up the bottom hole assembly while the bottom hole assembly is moved upward at a selected rate and distance. This method may be used to remove downhole solids, such as formation sands and proppant.

Abstract: Apparatus and methods for cleaning up a well including a coiled tubing inserted inside a spoolable compliant guide wherein well effluents can be flowed through the coiled tubing. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: To perform a cleanout operation in a wellbore, a cleaning tool having a coiled tubing and an electrical pump assembly is run into the wellbore. The electrical pump assembly that is located in the wellbore is activated. In response to fluid flow generated by the electrical pump assembly, removal of debris from the wellbore is caused by directing fluid containing the debris into the coiled tubing for delivery to an earth surface.

Abstract: The present invention relates to a fluid circulation system for circulating fluid in a subsea cavity, the cavity being filled with a first fluid and having first and second end ports. The system comprises a container (26) containing a second fluid, fluid lines (21, 27) extending from the container to the first and second end ports of the cavity, respectively, and a pump (22) for exchanging the second fluid provided in the container (26) and the first fluid provided in the subsea cavity (10). The invention also relates to a method for circulating fluid in a subsea cavity.

Abstract: A downhole oilfield completion method comprises determining a surge profile for a wellbore and assembling a downhole completion tool having an interior surge volume and comprising a surge attenuation system operable to reduce a surge of the downhole completion tool based at least in part on the surge profile. The method also comprises running the downhole completion tool into the wellbore and surging the wellbore by admitting wellbore fluid into the interior surge volume, the surge reduced at least in part by the surge attenuation system.

Abstract: A downhole swivel joint assembly comprising an upper component and a lower component. The components may assume either of two stable positions relative to each other, namely an unactivated configuration in which the components are rotationally fast with each other by virtue of the inter-engagement of splines of the lower component with splines of the upper component and an activated configuration in which the respective splines are disengaged so that the upper and lower components can rotate relative to each other. In the activated configuration the upper component is supported relative to the lower component on a ball bearing pack. Movement of the components between the activated and unactivated configurations is controlled by a resiliently deformable latch member which is C-shaped in transverse cross-section.

Abstract: A surfactant blend for servicing wells includes a first non-ionic surfactant having a hydrophilic-lipophilic balance of between about 10 and about 15; a second non-ionic surfactant having a hydrophilic-lipophilic balance of between about 2 and about 6; and an anionic surfactant.