摘要:
This invention relates to compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using water-in-water polymer emulsions to uniformly dissolve a rheologically active polymer, such as a thickener or friction reducer, in the treatment fluid. The emulsions have a low viscosity and are easily pumped for mixing into a treatment fluid, where upon dilution with an aqueous medium, the polymer is easily hydrated without forming fish-eyes. The partitioning agent in the water-in-water emulsion does not generally affect the rheology of the treatment fluid. The invention also relates to further processing of the emulsion by wet grinding, high shear mixing and/or heating to enhance the hydration rate in the preparation of the well treatment fluid.
摘要:
This invention relates to compositions and methods of treating a subterranean formation penetrated by a well bore including providing a treatment composition comprising a rheological polymer, a partitioning agent, a charged polyelectrolyte, and a first liquid medium, forming a stabilized heterogeneous mixture comprising a dispersed rheological polymer-rich phase and a partitioning agent-rich phase, and injecting the treatment fluid into the well bore. The invention relates to methods and compositions for preparing a well treatment fluid, including mixing polyethylene glycol partitioning agent, a charged polyelectrolyte, a first aqueous medium, and one or more rheological polymers selected from the group consisting of guar, modified guar, cellulose, modified cellulose, heteropolysaccharide, heteropolysaccharide derivative, or polyacrylamide, to hydrate the one or more polymers and form a water-in-water emulsion, and mixing the water-in-water emulsion with a second aqueous medium to form a well treatment fluid.
摘要:
Embodiments of this invention relate to compositions and methods of treating a subterranean formation penetrated by a well bore including introducing a Theological polymer into a subterranean formation, introducing a partitioning agent into a subterranean formation and forming a heterogeneous mixture comprising a dispersed Theological polymer-rich phase and a partitioning agent-rich phase, wherein the viscosity of the mixture is lower than the viscosity of the mixture when no partitioning agent is present. Embodiments of this invention relate to compositions and methods of treating a surface in contact with a wellbore and/or a subterranean formation penetrated by a well bore including forming a heterogeneous mixture comprising a dispersed Theological polymer-rich phase and a partitioning agent-rich phase at the surface of the subterranean formation, and introducing the mixture into a subterranean formation, wherein the viscosity of the mixture within the subterranean formation is lower than the viscosity of the mixture when no partitioning agent is present and wherein the viscosity of the mixture within the subterranean formation is lower than the viscosity of the mixture when the mixture is formed at the surface of the subterranean formation.
摘要:
A viscoelastic wellbore treatment fluid comprises an effective amount of an oligomeric surfactant for controlling the viscoelasticity of the fluid.
摘要:
Methods and apparatus for forming a fluid for use within in a subterranean formation including crosslinking a polymer along the surface of microspheres in a water-in-water emulsion and introducing the microspheres into the subterranean formation. Methods and apparatus for forming a fluid for use within in a subterranean formation including crosslinking a polymer along the surface of microspheres in a water in water emulsion, isolating the microspheres from the emulsion, and introducing the microspheres into the subterranean formation. Methods and apparatus for forming a fluid to treat a subterranean formation including introducing a crosslinkable polymer, partitioning agent, and crosslinker into a solvent, crosslinking the crosslinkable polymer, isolating beads of the crosslinkable polymer from the partitioning agent, introducing the beads into a fluid for treating a subterranean formation.
摘要:
Methods and compositions are disclosed for controlled addition of components that decrease the viscosity of the viscoelastic surfactant fluids or for controlled changes in the electrolyte concentration or composition of the viscoelastic surfactant fluids. One aspect of the invention relates to the use of internal breakers with a delayed activation. Another aspect of the invention relates to the use of precursors that release a breaking system such as alcohol by a process such as melting, slow dissolution, reaction with a compound present in the fluid or added to the fluid during or after the step of injecting, rupture of an encapsulating coating and de-adsorption of a breaking agent absorbed into solid particles. In another aspect of the invention, alcohols are included in a pad to reduce the low-shear viscosity and reduce the resistance to flow of the treatment fluids during a desired phase of the treatment.
摘要:
An aqueous fluid, possibly a wellbore fracturing fluid, comprises an aqueous solution or dispersion of a first polymer, which may be polysaccharide, as a thickener and a cross linking agent to enhance the viscosity of the fluid by crosslinking the first polymer, wherein the crosslinking agent is a second polymer comprising at least one polymer chain with phenyl boronate groups distributed along the polymer chain and the phenyl boronic acid groups have nitrogen attached to the phenyl group at a position which is meta relative to the boronate group.
摘要:
Process fluids comprising more than 1 wt % polyacrylamide and a non-metallic crosslinker may be used to control lost circulation in subterranean wells. The process fluid is placed into a subterranean lost-circulation zone and allowed to crosslink, thereby forming a gel barrier that limits further flow of process fluid into the zone. The non-metallic crosslinker may preferably comprise one or more polylactams. A pH-adjusting agent may also be incorporated into the process fluid.
摘要:
Disclosed herein is a gel or a gel concentrate comprising, polyacrylamide crosslinked with a non-metallic crosslinker comprising a polylactam. A well treatment fluid comprising the gel or the gel concentrate, a method of making the gel or the gel concentrate, and a method of using the gel or the gel concentrate are also disclosed.
摘要:
A method of providing a viscous emulsion at a subterranean location accessible via a wellbore, begins by providing an aqueous/aqueous emulsion comprising two aqueous solutions which, at surface temperature and pressure, are able to co-exist as separate aqueous phases in contact with each other. The two phases contain respective solutes which are sufficiently incompatible that they cause phase separation. The dispersed phase is rich in one solute, which may be a thickening polymer, while continuous phase is rich in a second solute, which may comprise surfactant. A hydrophobic liquid is dispersed in this emulsion to become the dispersed phase of a viscous emulsion whose continuous phase is provided by the aqueous/aqueous emulsion. The hydrophobic liquid and the aqueous/aqueous emulsion may be pumped separately down the wellbore to the subterranean location, and allowed to mix there so as to form the viscous emulsion at the subterranean location. On mixing, surfactant from the aqueous/aqueous emulsion may migrate to the oil/water interface, allowing the aqueous phases to become one phase with the result that the emulsion is further thickened by any thickening polymer in its composition. Even more thickening can be achieved by crosslinking the thickening polymer.