Abstract: A scale dissolver fluid for dissolving scale in a subterranean hydrocarbon-bearing formation comprises an effective amount of a scale dissolver formulation and an effective amount of a surfactant for controlling the viscosity of the fluid. In use, formation hydrocarbons act on the surfactant to reduce the viscosity of the fluid so that the fluid selectively invades a hydrocarbon-bearing zone of the formation.

Abstract: Compositions containing a peroxide or peracid and an organic acid salt buffer are provided. Also provided is a method for utilizing such compositions for removing polymers from oil and gas wells, while simultaneously dissolving encountered calcium carbonate deposits.

Abstract: The present invention relates to methods of chemically generating gas in aqueous fluids utilized in the drilling and completion of wells such as drilling fluids, spacer fluids, and aqueous acid solutions. In one embodiment, the invention provides a method of preventing the formation of fractures in a subterranean formation during a drilling operation. In other embodiments, the present invention provides methods of separating a first fluid and a second fluid in a subterranean formation; methods of forming lightweight well treatment fluids; methods of enhancing the permeability of a subterranean zone; lightweight drilling fluids; lightweight spacer fluids; foamed aqueous acidic well treatment fluids; and methods of making foamed aqueous and aqueous acidic well treatment fluids.

Abstract: A method of controlling and delaying the inversion of a drilling fluid and the wettability of a filtercake by using a delayed phase changing agent. The filtercake is preferably formed while drilling a subterranean formation using a drilling fluid includes: an oleaginous fluid; a non-oleaginous fluid; an amine surfactant having the structure: wherein R is a C12–C22 aliphatic hydrocarbon; R? is an independently selectable from hydrogen or C1 to C3 alkyl; A is NH or O, and 1?x+y?3. In the method, the filter cake is exposed to a delayed phase changing agent selected from the group consisting of aliphatic amine acids, salts of aliphatic amine acids and combinations thereof. In one preferred illustrative embodiment, the delayed phase changing agent is delivered in the form of a pill, the pill including a carrier fluid, a viscosifier and the delayed phase changing agent.

Abstract: The invention relates to pumping engineering, mainly to well pumping devices for extracting oil from wells. The inventive method consists in assembling from the bottom upward an input cone provided with a shank, a packer and a jet pump and in running said assembly with the aid of a tubing string into a well. Afterwards, a receiver transformer of physical fields is also run into said well, background measurements of temperature and other physical fields are carried out, a formation is drained and the work of the individual interlayer of a productive strata is evaluated. An ultrasonic action is performed on the productive strata. The hydrodynamic action being performed on the productive strata during said operation, the entire formation is exposed to the combined action of ultrasonic oscillations and a hydrodynamic effect. Afterwards, the unit for ultrasonic effect is pulled out from the well to the surface.

Abstract: Well completion spacer fluids containing fibers and methods of using the 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 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 spacer fluid are displaced from the well bore with the second fluid. The spacer fluid comprises water, a weighting material, a dispersing agent, a suspending agent and friction reducer and fibers. The spacer fluid containing the components mentioned above is preferably also foamed.

Abstract: A new class of sulfur scavenging or converting compositions is disclosed comprising diamine terminated, amine-aldehyde adducts, where the adducts are substantially bimolecular amine-aldehyde adducts and the composition is substantially free of trimer and/or triazines. Methods for making and using the new class of sulfur scavenging or converting composition are also disclosed.

Abstract: The present invention relates to methods and compositions for treating subterranean formations, and more specifically, to improved methods and compositions for generating acids for use downhole, for example, to at least partially degrade the acid-soluble portions of filter cakes deposited in subterranean formations. In one embodiment, the present invention provides a method of degrading an acid-soluble portion of a filter cake comprising contacting the acid-soluble portion of the filter cake with an acid generated from an orthoester.

Abstract: Single phase microemulsions improve the removal of filter cakes formed during drilling with invert emulsions. The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced.

Abstract: A method to synthesize a chlorine dioxide block remover in a well is described. The method includes dissolving a chlorate aqueous solution and some acidic substances in water and to produce a hydrogen ion. The chlorate aqueous solution and acidic substances are quickly injected into the well by an injection pump, so they react with each other and produce chlorine dioxide. The synthesis of the chlorine block remover in the well removes oil layer blocks induced by polymers and microbes, while reducing the risk of explosion caused by leaked chlorine dioxide, and reducing the corrosion of equipment and pipes caused by chlorine dioxide.

Abstract: Foamed completion fluids and methods of completing subterranean zones penetrated by well bores are disclosed. A method of completing a subterranean zone penetrated by a well bore comprises the steps of providing or preparing a foamed completion fluid comprising water, one or more salts, a gas and a capryl/capramidopropylbetaine surfactant foaming agent, introducing the foamed treating fluid into the subterranean zone, and then carrying out a completion operation in the subterranean zone.

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 for removing or dissolving calcareous materials in a subterranean formation or in a wellbore consists of two basic steps. In the first step, an aqueous acid solution is injected into the formation or wellbore. The aqueous acid solution contains between from about 15 to about 99 weight percent of an organic acid selected from formic acid, acetic acid or a mixture of formic acid and acetic acid. Water or brine is then injected into the formation or wellbore. The amount of water or brine injected into the formation or wellbore is an amount sufficient to reduce the concentration of organic acid in the formation or wellbore to no greater than 10 weight percent.

Abstract: Fluids useful in oil well drilling operations are described. The fluids comprise standard viscosifying and fluid loss control additives along with phosphonates or phosphate esters of organic ligands. The addition of the phosphonates or phosphate esters at effective concentrations prevents the adherence of heavy oil and heavy oil laden drill cuttings to drill pipe strings and well bore casings.

Abstract: Improved methods and compositions for degrading filter cake deposited in a subterranean formation are provided. These methods and compositions utilize particulates coated with acid-releasing degradable material wherein the released acid is used to degrade a filter cake.

Abstract: Methods in which temperature is used to control the foaming and/or defoaming of foamed treatment fluids comprising an aqueous liquid, an ionic foaming surfactant, and a gas are provided. A method of treating at least a portion of a subterranean formation is provided, the method comprising: providing a treatment fluid having a foam transition temperature, the treatment fluid comprising an aqueous liquid, and an ionic foaming surfactant; foaming the treatment fluid to form a foamed treatment fluid; circulating the foamed treatment fluid in a well bore penetrating the subterranean formation; and defoaming at least a substantial portion of the foamed treatment fluid, the defoaming comprising lowering the temperature of the foamed treatment fluid to about at or below the foam transition temperature.

Abstract: A method for controlling pressure of a dual well system includes drilling a substantially vertical well bore from a surface to a subterranean zone and drilling an articulated well bore from the surface to the subterranean zone using a drill string. The articulated well bore is horizontally offset from the substantially vertical well bore at the surface and intersects the substantially vertical well bore. The method includes drilling a drainage bore into the subterranean zone. The method includes pumping a drilling fluid through the drill string when drilling the drainage bore. The method includes pumping a pressure fluid down the substantially vertical well bore when drilling the drainage bore. The pressure fluid mixes with the drilling fluid to form a fluid mixture returning up the articulated well bore which forms a frictional pressure that resists fluid flow from the subterranean zone.

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 method of stimulating subterranean formations in oil and gas wells using a high pH buffered acid system. The method may be used to treat sandstone formations wherein the pH buffered acid system is used as the preflush or overflush or both. The method consists of introducing into the well a hydrofluoric acid containing sandstone acidizing solution either prior to or subsequent to introduction of the pH buffered acid system. The pH buffered acid system may further be used in the treatment of carbonate reservoirs. The pH of the buffered acid solution is substantially equivalent to that of the pH of the acidizing solution. The buffered acid solution is void of either hydrofluoric acid or hydrofluoric acid precursors.

Abstract: The invention relates to a method for treating subterranean formation comprising providing distributed temperature sensors, injecting a treatment fluid and monitoring the temperature across the treatment interval during the injection process.

Abstract: A down-hole well tool is disclosed for removing debris from a well utilizing low pressure/suction. More particularly, the tool is adapted to generate the low pressure within a well bore for removing debris while being interconnectable to the end of a single duct tubing that extends to the surface. Use of the low pressure/suction allows removal of debris without of forcing such debris into the permeable formations of the well. In one application, the tool may be utilized during open-hole completion processes. In another application, the tool may be utilized to clean existing wells.

Abstract: A method and a device for removing a hydrate plug (38) from a pipeline (16), wherein a pig (1), which is connected to an umbilical (2) extending to surface, is displaced down into the pipeline (16) until proximity of the hydrate plug (38), after which a fluid arranged with hydrate-plug-dissolving properties is pumped through the umbilical (2).

Abstract: The current invention provides improved methods and compositions for completing a well bore. In one aspect, the current invention provides a process for preparing a foamed well composition. The process utilizes air to foam the composition after the air has been treated to lower the oxygen content below that concentration necessary to support combustion. Additionally, the current invention provides a process for completing and/or treating a well bore using a foamed composition wherein the foam is generated with reduced oxygen content air. Finally, a preferred embodiment of the invention provides a foamed cement composition wherein the gaseous portion of the composition is air having a reduced oxygen content.

Abstract: Methods of diverting treating fluids in subterranean zones penetrated by well bores are provided. The methods basically comprise the following steps. A degradable particulate diverting material is placed in a subterranean zone that contains releasable water. A treating fluid is then introduced into the subterranean zone which is diverted by the degradable particulate diverting material therein. Thereafter, the degradable particulate diverting material is allowed to at least partially degrade in the presence of the released water in the subterranean zone.

Abstract: The present invention provides the use of surface-modified nanoparticles in fluids used to recover hydrocarbon from underground formations. The use of surface-modified nanoparticles in such fluids provides foams that are stable under pressure yet have a shorter foam lifetime than typical surfactant-stabilized foams after the pressure is released or lowered.

Abstract: Compositions and methods for the inhibition of salt formation in oil and gas wells are disclosed. In particular, nitrilotriacetamide and its salts are effective at treating existing salt formations, and in inhibiting formation of new deposits.

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: Methods are provided for removing filter cake containing a bridging agent soluble in a carboxylic acid salt from a formation fluids producing zone penetrated by a well bore. The methods basically comprise the steps of introducing in an aqueous carrier liquid a carboxylic acid ester and a base for slowly catalyzing the hydrolysis of the ester and forming a carboxylic acid salt therewith into the producing zone, and allowing the base to catalyze the hydrolysis of the carboxylic acid ester to form the carboxylic acid salt so that the carboxylic acid salt dissolves the bridging agent and the filter cake is removed.

Abstract: A micro device in which a functional element can be moved between an operating position and a waiting position by the displacement of support means coupled to a substrate. The micro device has a cantilever structure in which one end of support means is made a fixed one fixed to the substrate and the other end to which an active element is provided is made a free end. A spring portion is provided to at least part of the support means, and thus the active element can be greatly displaced by a small stress.

Abstract: Apparatus connected to the downhole end of a tubing string for cleaning and flushing wells has a threaded connection to the string and at least one primary jet to direct circulating gases toward the downhole end of the well, together with a plurality of secondary jets which are arranged around the exterior of the tubular member and directed upwardly at an acute angle with respect to the longitudinal axis of the tubular member and skewed radially at an acute angle with respect to the surface of the tubular member the skew angle being opposed to the thread angle so as to tend to tighten the threaded connection and the upwardly directed gas volume being approximately one and one-half to four times that which is directed toward the downhole end of the well.

Abstract: An apparatus for increasing oil and gas recovery includes a delivery mechanism for automatically introducing a flow enhancing substance into a plunger of an oil or gas well and method.

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: 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: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: A method and apparatus for substantially cleaning fill from a borehole is described variously including running a coiled tubing assembly into the wellbore, creating a fluid vortex by circulating cleaning fluid through the coiled tubing, and pulling the coiled tubing and coiled tubing assembly out of the hole at a speed sufficient to substantially clean the particulate solids from the wellbore. An apparatus for substantially cleaning fill from a hole, including vertical, horizontal, or deviated wells also is provided.

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: Junk basket 10 is provided for collecting debris from a wellbore cleaning operation, and includes a central mandrel 14 having a throughbore 16 and an outer shell 24 defining a generally annular junk space 40. The outer shell 24 may be configured such that the annulus 27 includes a reduced portion 28. Flow holes 30 in the outer shell are preferably angled substantially upward, and are positioned to discharge fluid to the annulus 27. According to a method of the invention, fluid is passed from an upper tubing string, through the central mandrel, into the wellbore and upward through the annulus and past the flow holes, thereby reducing pressure of flow past the well holes to pass fluid from the junk space through the flow holes.

Abstract: A tool and method for treating an open hole just before expanding a screen into position is described. The swage is hydraulically driven and permits flow through it and out lateral ports to impact the borehole wall. A cup seal assembly below and a packer up above insure that the fluid impacts the borehole wall with sufficient force to dislodge the mud cake. Another feature of the invention is that the surface treatment and screen expansion can be done in one trip. The pressurized fluid that drives the swage also provides the fluid energy to prepare the borehole wall just before the screen is expanded against it.

Abstract: A method is disclosed for intermittently mitigating hazardous sulfur compounds, such as hydrogen sulfide, mercaptans and sulfur oxides, from a fluid in the head space of a wellbore. The method comprises contacting the fluid with a foamed aqueous stream comprising an active scavenging agent, such as a triazine, and a stiff foaming agent. The scavenging agent reacts with hazardous sulfur compounds to eliminate the compounds from the fluid stream in the vapor space of the wellbore without withdrawing the hydrocarbon from the wellbore and without releasing hazardous sulfur compounds to the environment.

Abstract: Method and apparatus for substantially cleaning fill from a borehole, variously including in preferred embodiments disturbing particulate solids of fill while RIH, entraining particulates while POOH, jetting downhole while RIH and jetting uphole while POOH, and controlling at least one of a pump rate regime or a POOH rate regime.

Abstract: A method for treating a wellbore (or well casing) and the contiguous wellbore area to remove scale (mineral deposits comprised of, e.g., BaSO4, CaCO3, etc.) in the context of hydrocarbon recovery and other applications is disclosed, said method including contacting the scale with a fluid comprised of an ionic liquid or liquids.

Abstract: Methods and compositions for treating subterranean zones penetrated by well bores utilizing environmentally safe viscous fluids including a solubility increasing boron complex or ester forming compound. A method of the invention comprises the following steps. A viscous treating fluid composition is provided comprising 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: A combined scale inhibitor treatment and water control treatment requires fewer steps than the sum of each treatment procedure practiced separately. The control of water production simultaneously further reduces the amount of scale formed. Conventional water control chemicals and scale inhibitors of a wide variety of types can still be employed to advantage, and the same equipment may be used as employed for the treatments implemented separately.

Abstract: A composition, formulation, and method for removing water from a near-wellbore portion of a subterranean formation containing a crude oil and penetrated by a wellbore. The formulation contains alkylpolyglycoside, ethoxylated alcohol and linear alkyl alcohols. The composition contains a hydrocarbonaceous liquid, alkylpolyglycoside, ethoxylated alcohol and linear alkyl alcohol.

Abstract: A method for increasing the permeability of a subterranean formation is disclosed in which an amount of an aqueous mixture, sufficient to increase the permeability of the formation, comprising specified aminopolycarboxylic anionic species, and specified cationic species, is injected into the formation matrix.

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 wellbore cleanup tool and method are described. In one embodiment, the fluid is displaced with a cup seal into the tubing/drill pipe as the seal is lowered into the wellbore. In another embodiment reverse circulation directs debris into the tubing/drill pipe as it is loosened on the trip into the hole. The returning fluid laden with debris can be directed to either below the cleaning equipment or above it when used with a cup seal and a return port adjacent to it.

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: A wellbore fluid including a peroxide degradable polymer and an encapsulated peroxide source. The peroxide degradable polymer may be a polysaccharide. The peroxide source may include an inorganic peroxide, including zinc and alkaline earth metal peroxides, such as magnesium peroxide. The encapsulating material may be a polymer, including enteric polymers. The release of peroxide, from peroxide sources generally, can be controlled by means of pH such that peroxide source can be activated, and peroxide released, by a change in pH. In a wellbore, this pH change can be effected by using produced fluids to lower the pH of a more basic wellbore fluid.

Abstract: A reciprocating pump vent-dump and methods of use for utilization in the hydrocarbon industry. The device is preferably used with barrel pumps although it may be used with tubing pumps. The device is positioned at the bottom of the wellbore immediately above the stinger and immediately below above the standing valve and comprises a sliding piston within an outer housing. The device may be opened pulling upwards on the pump drive mechanism thereby allowing fluid within the production tubing to drain back into the formation as long as the pump drive mechanism is held up. The device closes when the pump is returned to normal operation. The method of spotting chemicals requires a pre-measured quantity of chemicals at the surface which is sucked into the tubing string when the valve is opened followed by a pre-measured quantity of make-up fluid which is drawn into the well thereby placing the chemicals at the required point.