Abstract: Fluid systems may contain elements to provide changes in bulk fluid density in response to various environmental conditions. One environmental driver to the variable density is pressure; other environmental drivers include, but are not limited to, temperature or changes in chemistry. The variable density of the fluid is beneficial for controlling sub-surface pressures within desirable pore pressure and fracture gradient envelopes. The variability of fluid density permits construction and operation of a wellbore with much longer hole sections than when using conventional single gradient fluids.

Abstract: Water-based drilling mud lubricants using a blend of fatty acid polyamine salts and fatty acid esters give synergistically better lubricity results than either component used separately. For example, the blends with different ratios of fatty acid diethylenetriamine salt and fatty acid methyl ester demonstrate much better lubricity in water-based drilling fluids than those where only fatty acid diethylenetriamine salt or fatty acid methyl ester are separately used. The amines in fatty acid amine salt might also include other polyamines, such as butanediamine pentamethylenediamine, spermidine, spermine, propylene diamine and propylene polyamines. The fatty acid esters might also include fatty acid ethyl ester, fatty acid glycerol ester and fatty acid trimethylolpropane ester. The carbon numbers of the fatty acids used to make the components in the lubricant blend may range from C4 to C28.

Abstract: Methods for drilling and treating for lost returns continuously while drilling are provided. High fluid loss drilling fluid is used, along with particulate material that forms an immobile mass in hydraulic fractures to prevent their growth. The particulate material may be selected based on the predicted size of a hydraulic fracture, based on particle size to minimize fines, based on specific gravity to attain high solids content for a selected fluid density, and/or based on permeability of the particles to attain a high spurt loss.

Abstract: Of the many compositions and methods provided herein, one method includes a method of preventing emulsification of crude :oil into an aqueous-based treatment fluid, comprising: contacting, crude oil in a well bore with the aqueous-based treatment fluid comprising a styrene-acrylate copolymer. Wherein the crude oil has an API gravity of about 10 or greater; and allowing the styrene-acrylate copolymer to interact with the crude oil in the well bore.

Abstract: A method of controlling a fluid jet can include discharging fluid through an outlet of a jetting device, thereby causing the fluid jet to be flowed in multiple non-coplanar directions, and the fluid jet being directed in the non-coplanar directions by a fluidic circuit of the jetting device. A jetting device can include a body having at least one outlet, and a fluidic circuit which directs a fluid jet to flow from the outlet in multiple non-coplanar directions without rotation of the outlet. A method of drilling a wellbore can include flowing fluid through a fluidic switch of a jetting device, thereby causing a fluid jet to be discharged in multiple non-coplanar directions from the jetting device, and the fluid jet cutting into an earth formation.

Abstract: Nanoemulsions have been discovered to be useful to the oil field. More particularly water-in-oil (W/O), oil-in-water (O/W) and other classes of nanoemulsions have found beneficial application in drilling, completion, well remediation and other oil and gas industry related operations. Additionally, nanoemulsions may reduce friction pressure losses, as well as reduce subsidence of solid weight material during oil and gas operations. New preparation methods for nanoemulsions have also been discovered.

Abstract: A Drill-To-The-Limit (DTTL) drilling method variant to Managed Pressured Drilling (MPD) applies constant surface backpressure, whether the mud is circulating (choke valve open) or not (choke valve closed). Because of the constant application of surface backpressure, the DTTL method can use lighter mud weight that still has the cutting carrying ability to keep the borehole clean. The DTTL method identifies the weakest component of the pressure containment system, such as the fracture pressure of the formation or the casing shoe leak off test (LOT). With a higher pressure rated RCD, such as 5,000 psi (34,474 kPa) dynamic or working pressure and 10,000 psi (68,948 kPa) static pressure, the limitation will generally be the facture pressure of the formation or the LOT. In the DTTL method, since surface backpressure is constantly applied, the pore pressure limitation of the conventional drilling window can be disregarded in developing the fluid and drilling programs.

Abstract: A drilling composition is provided. The composition includes: I) an organic phase comprising components: i. from about 20 wt. % to about 99.999 wt. %, based on the total weight of components i. and ii., of at least one linear or branched, cyclic or non-cyclic, saturated hydrocarbon; ii. from about 0.001 wt. % to about 25 wt. %, based on the total weight of components i. and ii., of at least one ester; II) from 0 to about 50 wt. %, based on the total weight of the composition, of water or aqueous phase; III) from 0 to about 60 wt. %, based on the total weight of the composition, of at least one additive, wherein the sum of the weight components I) to III) is 100 wt. %.

Abstract: An additive for a water-based mud drilling fluid or for drill-in fluids comprises a 0.5 wt % solution of 87-89 mole % hydrolysed polyvinylalcohol, having a weight average molecular weight of about 20,000. Use of the additive may reduce susceptibility of a wellbore to blockages, reduce accumulation of accretions between a drill string and wellbore casing, reduce bit-balling and facilitate separation of undesirable insoluble solids from a drilling fluid returned to the surface.

Abstract: A water-based polymer drilling fluid, containing effective quantities of surfactants having HLB numbers equal to or greater than approximately 7, emulsifies oil and bitumen contained in oil sand cuttings, resulting in the oil and bitumen being dispersed into the mud as an emulsion. This eliminates or significantly reduces the ability of the oil, bitumen, and cuttings to clog the well or stick to drill string components when drilling a well through oil-bearing sands, particularly sands containing highly viscous oil or bitumen. The emulsification process separates the sand particles from the oil and bitumen, such that the sand particles can be removed when the mud is run through a conventional shale shaker or other suitable apparatus.

Abstract: Wellbore fluids containing poly(trimethylene ether)glycols are provided. The wellbore fluids can provide enhanced functionality, improved cost effectiveness, and reduced environmental impact as compared to conventional wellbore fluids.

Abstract: Methods and compositions are disclosed that comprise cement kiln dust having a mean particle size that has been altered. An embodiment discloses a subterranean treatment method comprising: introducing a treatment fluid into a subterranean formation, wherein the treatment fluid comprises cement kiln dust having a mean particle size that has been altered from its original size by grinding, separating, or a combination thereof. Another embodiment discloses a subterranean treatment method comprising: introducing a treatment fluid into a subterranean formation, wherein the treatment fluid comprises cement kiln dust having a mean particle size that has been reduced from its original size.

Abstract: Modified surfactants may be added to an oil-based drilling fluid where the modified surfactant is selected from the group consisting of an extended surfactant, a dendritic surfactant, a dendritic extended surfactant, and combinations thereof. These oil-based drilling fluids may be used for drilling a well through a subterranean reservoir, while circulating the oil-based drilling fluid through the wellbore. The oil-based drilling fluid may include at least modified surfactant, at least one non-polar continuous phase, and at least one polar non-continuous phase. The modified surfactant may have propoxylated/ethoxylated spacer arms extensions. The modified surfactant may have intramolecular mixtures containing hydrophilic and lipophilic portions. They attain high solubilization in the oil-based drilling fluid and may be, in some instances, insensitive to temperature making them useful for a wide variety of oil types.

Abstract: A method for forming a wellbore in a heated formation includes flowing liquid cooling fluid to a bottom hole assembly in a wellbore in a heated formation. At least a portion of the liquid cooling fluid is vaporized at or near a region to be cooled. Vaporizing the liquid cooling fluid absorbs heat from the region to be cooled.

Abstract: Drilling fluids comprising polymers containing hydroxylated structural units are useful as accretion inhibiting agents, and/or as fluid rheology controlling agents, and/or as filtrate reducing agents, and/or as lubricating agents.

Abstract: Lost circulation of drilling fluid is one of the most serious and expensive problems facing the drilling industry. The present invention relates to an improved drilling fluid for reducing or preventing lost circulation to an underground formation surrounding a well bore in the process of drilling a well. The drilling fluid comprises a base fluid and wax or waxy substance as a primary seepage loss agent. In a particularly preferred embodiment, the seepage loss agent does not include particles having a blend of natural wax and synthetic wax together in a single particle. The invention also provides a method of reducing or preventing lost circulation to an underground formation surrounding a well bore in the process of drilling a well using the drilling fluid of the invention, wherein the primary seepage loss agent is added to the drilling fluid, either before or during drilling, and the drilling fluid is pumped down hole during drilling.

Abstract: A method of cleaning a wellbore drilled with a drilling fluid that forms a filter cake that includes emplacing a breaker fluid into the wellbore, the breaker fluid comprising: an aqueous fluid; a fragmentation agent; and an amphoteric chemotrope; and shutting in the well for a period of time sufficient to initiate breaking of the filter cake is disclosed.

Abstract: A method of preparing and using a subterranean formation stabilization agent. The stabilization agent includes a guanidyl copolymer and may be admixed with a fracturing fluid and optionally brine. The stabilization agent is effective in preventing and/or reducing, for example, clay swelling and fines migration from a subterranean formation contacted with the stabilization agent.

Abstract: A wellbore fluid that includes an oleaginous base fluid; and a silanated weighting agent is disclosed. In particular, the silanated weighting agents may be produced by reaction between an alkyl alkoxy silane and a weighting agent Methods of formulating such fluids and methods of drilling using such fluids are also disclosed.

Abstract: The present disclosure is directed to a method comprising: mixing (i) a zwitterionic polymer prepared by inverse emulsion polymerization of at least one monomer Ab comprising a betaine group and optionally one or more nonionic monomers Ba, (ii) a surfactant and (iii) produced water to form a well servicing fluid. The resulting well servicing fluid is introduced into a hydrocarbon well.

Abstract: Clay is stabilized in methods for drilling of wells and other formation treatment for hydrocarbon production by the addition to the drilling or other fluid including a choline compound together with an formation control additive.

Abstract: The invention relates to a method for drilling shafts (2) in ground layers (3). The method comprises of arranging a borehole casing (4) in the ground (3), lowering into the borehole casing (4) a hollow drill string (5) provided with a drill head (7) with cutting tools (8), arranging a water column (10) in the borehole casing (4), and then setting the drill string (5) into rotation (20) in the borehole casing (4) so that ground material (31) is dislodged by the cutting action of the cutting tools (8). At the position of the drill head (7) a first fluid (26) is injected under a first pressure into the ground layers (3) by means of one or more nozzles (25). The method has a higher drilling efficiency than the known method. The invention also relates to a device for performing the method, and a jack-up pontoon provided with the device.

Abstract: A composition comprising a nonionic fluorinated polymeric surfactant having a weight average molecular weight of least 100,000 grams per mole, the nonionic fluorinated polymeric surfactant comprising: divalent units independently represented by formula (I): in a range from 30% to 65% by weight, based on the total weight of the nonionic fluorinated polymeric surfactant; and divalent units independently represented by formula (II): in a range from 70% to 35% by weight, based on the total weight of the nonionic fluorinated polymeric surfactant. Rf is a perfluoroalkyl group having from 3 to 4 carbon atoms; R and R2 are each independently hydrogen or alkyl of 1 to 4 carbon atoms; R1 is alkyl of 16 to 24 carbon atoms; and n is an integer from 2 to 11. Foams comprising the nonionic fluorinated polymeric surfactant and a liquid hydrocarbon and methods of making and using the foams are also disclosed.

Abstract: The present invention generally relates to a polyamide emulsifier, to a drilling fluid composition that comprises said emulsifier and to a method of drilling a borehole into a subterranean formation utilizing the drilling fluid composition of the invention.

Abstract: A method comprises providing a drilling fluid comprising: an aqueous fluid; and a microemulsion surfactant; and drilling a well bore in a subterranean formation comprising an oleaginous fluid using the drilling fluid, wherein the microemulsion surfactant forms a microemulsion with the oleaginous fluid within the well bore. In accordance with the method, the subterranean formation has a retained producibility greater than about 50%.

Abstract: An excavator for underground excavating arranged to perform excavating work with low vibration and low noise. A rotary excavator and an underground excavating method are also provided. The excavator (1) for underground excavating comprises a plurality of bits (42a, . . . ) having the outside diameter smaller than that of the excavator body (2) and advancing/retracting to/from the excavating side, piston case members (22b, . . . ) incorporating pistons (61) for applying a hitting force to respective bits (42a, . . . ) by the energy of working fluid, a section (30) for storing the working fluid being fed to respective piston case members (22b, . . . ), working fluid circulation passages (352) for allowing the working fluid being fed to respective piston case members (22b, . . . ) to pass, and a body of rotation (40) provided with a plurality of holes (4a, . . . ) for allowing the fluid storage section (30) to communicate with the circulation openings (3a, . . .

Abstract: New oil-based foam drilling fluids for oil and/or gas wells include a base oil, a foaming agent and a polymer including at least one aromatic olefin monomer and at least one diene monomer. The polymer improves foam properties rendering a foam stable at temperatures at or above 350° F.

Abstract: There is provided a system and method for having multiple movable isolation zones within a borehole, to provide for zones having predetermined properties, such as pressure, flow or optical properties. These movable isolation zones provide advantages in downhole activities, such as, laser cutting and laser drilling to advance a borehole.

Abstract: A drilling fluid includes a base fluid and a circulation loss reducing additive package having a polysaccharide, a cellulose derivative and a pH controlling component.

Abstract: The invention relates to the use of one or more water-soluble reactive liquid component capable of subsequent polymerization or cross-linking to form a solid to improve the zonal isolation and alleviate the impacts of cracks and fissures in the cement sheath around a completed subterranean well. It includes the steps of injecting a wellbore fluid carrying the reactive component or additive into the wellbore, injecting a cementitious composition as slurry into the wellbore and letting said reactive liquid component pass through at least one of the interfaces between cement and formation, cement and filter cake, and filter cake and formation before forming a solid of said reactive liquid component that traverses said at least one of the interfaces.

Abstract: A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a particle size of at least 90% by volume less than 50 ?m.

Abstract: An inhibitive water-based polymer mud system and method for using the system in drilling and in stabilizing wellbores is disclosed for use in water sensitive formations as an alternative to oil-based muds. The system comprises a fresh water or salt water base thinned or dispersed with a water soluble, biodegradable polyamide-based copolymer having at least one grafted side chain formed from ethylenic unsaturated compounds. This system is effective and has stable rheology over a broad pH range, even at a near neutral pH of 8.0. The drilling fluids do not contain heavy metals and are rheologically tolerant to contaminants such as cement, anhydrite and sodium and temperatures as high as about 400° F.

Abstract: In oil or gas well drilling, saline water is collected and separated into first and second streams of solid or liquid products containing salts. The first or second product is added to drilling fluids as a weighting agent.

Abstract: The present invention relates to glycerol based drilling fluids. In particular, the invention relates to drilling fluids comprising a 95-20 volume % glycerol/water solution capable of stabilizing water-sensitive formations during drilling and the use of such solutions for drilling a well having water-sensitive formations.

Abstract: The lubricity of a drilling fluid or a completion fluid may be increased by incorporating into the fluid a water-soluble or water-dispersible salt of a sulfonated (sulfated) vegetable oil or a derivative thereof, such as a sulfonated (sulfated) castor oil. Suitable derivatives include the sodium, potassium, calcium, magnesium or ammonium salt. A non-ionic or anionic surfactant which is capable of enhancing the solubility of the salt may further be incorporated into the drilling fluid or completion fluid.

Abstract: A drilling fluid has a redispersible polymer powder introduced as a water dispersion that is capable of providing a deformable latex film on at least a portion of a subterranean sand formation and which inhibits or controls fluid loss and acts as a sealing agent when used to drill in sand formations for hydrocarbon recovery operations. The redispersible polymer powder may be made by drying the emulsion in which they are formed and then grinding into a powder or by spray drying. The polymer particles of suitable size precipitate or collect or assemble onto the pores of a subterranean sand formation to at least partial seal the formation with a deformable polymer film.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids.

Abstract: Gas hydrate formation in a well completion fluid in the annular space of a hydrocarbon producing well may be controlled by the incorporation of effective amounts of one or more low dose gas hydrate inhibitors, including but not limited to, low dosage hydrate inhibitors (LDHIs), kinetic hydrate inhibitors, dendrimeric or branched compounds, linear polymers and copolymers, grafted or branched linear polymers and copolymers, and onium compounds.

Abstract: A system for forming a subterranean wellbore may include a pump and an additive supply. The pump pumps a drilling fluid into the wellbore while also generating a pressure differential that draws an additive across a supply line connected to the additive supply. The drilling fluid may be a gas or a liquid. A method for forming a wellbore may include drilling the wellbore, circulating a drilling fluid in the wellbore using a pump; and supplying an additive to the drilling fluid by flowing the additive across a supply line using a pressure differential generated by the pump. The pump may generate a vacuum pressure at a supply line outlet and/or create a pressure differential in the supply line. The flow of additive across the supply line may be regulated and/or stopped when the pump is not operating.

Abstract: A process is disclosed for treating an underground formation, which process comprises: (a) introducing into the underground formation a micellar dispersion comprising water, one or more organic acid precursors, one or more surfactants and, optionally, one or more salts, co-surfactants and/or organic liquids that are not organic acid precursors; and (b) allowing (i) the micellar dispersion to solubilize hydrocarbons, emulsions or water blocks present in the underground formation, and (ii) at least a portion of the organic acid precursor to hydrolyze in-situ to produce sufficient organic acid to substantively dissolve acid soluble material present in or adjacent to filter cakes or other damage in the underground formation.

Abstract: A water-based drilling fluid and method of using same are presented in this disclosure, which fluid is used in drilling wells through a formation containing a shale that swells in the presence of water. The drilling fluid comprises an aqueous based continuous phase; a weighting material; and a shale hydration inhibition agent (SHIA) selected from the group consisting of propylamine derivatives, hydrogenated poly(propyleneimine) dendrimers (HPPID), and polyamine twin dendrimers (PTD). In some embodiments, the SHIA of this disclosure is not hydrolyzed at a temperature in the range of from about 100° F. to about 500° F. The drilling fluid may further comprise a fluid loss control agent, an encapsulating agent, other additives, and combinations thereof. A method of reducing shale swelling during wellbore drilling is also described. The method comprises circulating in the subterranean well a water-based drilling fluid comprising an aqueous based continuous phase, a weighting material, and a SHIA.

Abstract: Methods and apparatus are described to drill and complete wellbores. Such wellbores include extended reach horizontal wellbores, for example in shales, deep subsea extended reach wellbores, and multilateral wellbores. Specifically, the invention provides simple threaded subassemblies that are added to existing threaded tubular drilling and completion equipment which are used to dramatically increase the lateral reach using that existing on-site equipment. These subassemblies extract power from downward flowing clean mud, or other fluids, in an annulus to provide additional force or torque on tubular elements within the wellbore, while maintaining circulation, to extend the lateral reach of the drilling equipment and completion equipment. These added elements include combinations of The Leaky Seal™, a Cross-Over, The Force Sub™ and The Torque Sub™. The use of such additional simple elements allow lighter drilling equipment to be used to reach a given lateral distance, therefore reducing drilling costs.

Abstract: An invert emulsion drilling fluid, and a method of drilling with such fluid, having improved rheology at low mud weights and high temperatures. The improved rheology is effected with addition of hydrophobic amines, most preferably dimer diamines.

Abstract: A wellbore fluid comprising a base fluid and a particulate bridging agent comprised of a sparingly water-soluble material selected from the group consisting of melamine (2,4,5-triamino-1,3,5-triazine), lithium carbonate, lithium phosphate (Li3PO4), and magnesium sulfite.

Abstract: A method of preventing or treating lost circulation during the drilling of a well comprises the addition, at concentration ranging between about 0.5 and 6 pounds per barrel, of water-dispersible fibers having a length between about 10 and 25 mm, for instance glass or polymer fibers, to a pumped aqueous base-fluid including solid particles having an equivalent diameter of less than 300 ?m. The base-fluid with the solid particles can be the drilling fluid or a small-volume pill specially pumped for curing lost circulation.

Abstract: A method and drilling apparatus for drilling. The drilling is carried out by a drilling apparatus including a drilling device including a casing part and at least during drilling a drilling unit. At the drilling head of the drilling apparatus are at least first drilling elements, a second drilling element, a flushing flow arrangement and a pressure medium operated hammering device. The first drilling elements are coupled with the second drilling element power-transmittedly in order to carry out cooperation thereof at least during drilling with the second drilling elements for a rotational motion, a feeding motion and the hammering motion, and are coupled removably to enable removal thereof from the hole. For producing the hammering motion a hammering device is used that is operated essentially by a water-based pressure medium. At least a part of the water-based pressure medium operating the hammering device is used as the flushing medium.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids. The chlorosulfonated a-olefin copolymers that are useful in the practice of this invention are typically chlorosulfonated ethylene/octene copolymers or chlorosulfonated ethylene/butene copolymers. The utilization of chlorosulfonated ?-olefin copolymers in oil-based drilling fluids offers (1) long service life at high operating temperatures, (2) minimal formation damage, (3) improved filtration behavior, and (4) highly effective performance at low viscosifier levels.

Abstract: A system for controlling drilling mud density in drilling operations that combines a base fluid of lesser/greater density than the drilling fluid required at the drill bit to drill the borehole to produce a combination return mud in a riser. Concentric tubular members are disclosed, wherein one tubular member, such as the drill string, is utilized to inject the drilling fluid into the wellbore. Another tubular member carries the combination fluid to the surface for separation by a centrifuge system. By combining appropriate quantities of drilling mud with another fluid, the density of the combination fluid carrying drill cuttings to the surface can be regulated. During separation by the centrifuge, a weir plate having an adjustable height is utilized in the centrifuge to regulate the separation of the base fluid from the drilling fluid, producing a high density fluid and a low density fluid.

Abstract: A method of drilling or gas-lifting is disclosed where the methods including the use of a foaming agent and a gas, where the foaming agent is a keratin and the hydrostatic pressure of the fluid in the well is for a portion of the drilling or gas-lift operation less than an hydrostatic pressure of the formation being drilled or under production.

Abstract: Methods of treating a wellbore comprise displacing a drilling fluid comprising an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage into the wellbore. Methods of drilling a wellbore comprise: applying torque to a bit within the wellbore and concurrently applying force to urge the bit to extend through the wellbore; and circulating a drilling fluid past the bit to remove cuttings therefrom, the drilling fluid comprising an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage. Methods of preparing a drilling fluid comprise: forming an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage; and combining the organophilic clay with an oil-based fluid.