Abstract: A treatment fluid and system are disclosed for cleaning borehole filtercake using the treatment fluid, wherein the filtercake contains reservoir drilling fluid (RDF) solids. The treatment fluid comprises a fluoride source providing a 1.2 to 5 molar fluoride concentration, and another acid or combination of acids to provide a pH between 1.8 and 5. The treatment fluid is balanced for a dissolving power high enough to have significant dissolution of the filtercake, but low enough for even propagation to avoid premature leak-off.

Abstract: A treatment fluid and a method are disclosed for cleaning borehole filtercake using the treatment fluid, wherein the filtercake contains reservoir drilling fluid (RDF) solids. The method includes pumping the treatment fluid downhole in contact with the filtercake to be removed to establish a differential pressure between the treatment fluid and the formation adjacent the filtercake, and evenly propagating treatment of the filtercake during the differential pressure period to delay breakthrough by the treatment fluid for a period from 1 to 12 hours. The treatment fluid comprises a fluoride source providing a 1.2 to 5 molar fluoride concentration, and another acid or combination of acids to provide a pH between 1.8 and 5. The treatment fluid is balanced for a dissolving power high enough to have significant dissolution of the filtercake, but low enough for even propagation to avoid premature leak-off.

Abstract: Gravel packing of a wellbore penetrating a subterranean formation is carried out in a wellbore having a cased section and an uncased section that contains water-based drilling fluids. A first water-based displacement fluid that contains a shale inhibitor is introduced into the wellbore to displace the water-based drilling fluids from the uncased section of the wellbore. A second water-based displacement fluid is introduced into the wellbore to displace fluids within the cased section of the wellbore. A sand control screen assembly is run to a selected depth within the uncased section of the wellbore to facilitate a gravel packing operation. A gravel pack slurry containing gravel and a viscosified carrier fluid is introduced into the wellbore to facilitate gravel packing of the uncased section.

Abstract: A method of installing a sand control screen assembly in a wellbore penetrating a subterranean formation is carried out in a wellbore having a cased section and an uncased section. The wellbore contains synthetic or oil-based drilling fluids containing drilled solids. A first water-based displacement fluid that contains a shale inhibitor is introduced into the wellbore to displace the synthetic or oil-based drilling fluids from the uncased section of the wellbore. A second water-based displacement fluid is introduced into the wellbore to displace fluids within the cased section of the wellbore. The sand control screen assembly is then run to a selected depth within the uncased section of the wellbore to facilitate a gravel packing operation.

Abstract: A method of gravel packing a wellbore penetrating a subterranean formation is provided. The wellbore has a cased section and an uncased section and contains synthetic or oil-based drilling fluids containing drilled solids. To carry out the method, fresh synthetic or oil-based displacement fluid that is free of drilled solids is introduced into the wellbore to displace the synthetic or oil-based drilling fluids from the uncased section of the wellbore. A water-based displacement fluid is introduced into the wellbore to displace fluids within the cased section of the wellbore. A sand control screen assembly is run to a selected depth within the uncased section of the wellbore. A gravel pack slurry containing gravel and a water-based carrier fluid is then introduced into the 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 system includes a wellbore intersecting a subterranean formation and a treatment flowpath disposed in the wellbore including a fluid path from a surface location to the subterranean formation and returning to the surface location. The treatment flowpath has a delivery flowpath upstream of the subterranean formation and a pertinent flowpath at and downstream of the subterranean formation. The system further includes a gravel pack assembly having a first crossover port fluidly coupling the delivery flowpath to the pertinent flowpath, a screen, a washpipe, and a second crossover port fluidly coupling the washpipe to a return portion of the pertinent flowpath. The system further includes a friction reducing agent that is effective in at least part of the pertinent flowpath, but that is not a friction reducer in solution in the treatment fluid at the surface location.

Abstract: A treatment fluid and a method are disclosed for cleaning borehole filtercake using the treatment fluid, wherein the filtercake contains reservoir drilling fluid (RDF) solids. The method includes pumping the treatment fluid downhole in contact with the filtercake to be removed to establish a differential pressure between the treatment fluid and the formation adjacent the filtercake, and evenly propagating treatment of the filtercake during the differential pressure period to delay breakthrough by the treatment fluid for a period from 1 to 12 hours. The treatment fluid comprises a fluoride source providing a 1.2 to 5 molar fluoride concentration, and another acid or combination of acids to provide a pH between 1.8 and 5. The treatment fluid is balanced for a dissolving power high enough to have significant dissolution of the filtercake, but low enough for even propagation to avoid premature leak-off.

Abstract: Method and apparatus for gravel packing an open-hole wellbore are disclosed. The apparatus includes a sandscreen disposed in the wellbore thereby creating an annulus between the wellbore and the sandscreen for receiving a gravel slurry. The apparatus further comprises a tubular member or wash pipe which is concentrically disposed in the sandscreen for receiving carrier fluid which passes through the sandscreen and for returning the carrier fluid to the earth's surface. At least one diverter valve is installed in the tubular member for permitting flow of the carrier fluid into the tubular member.

Abstract: A method of treating a formation with a well treatment fluid comprising a clay stabilizer comprising a polyamine ether before or during a well treatment such as cleanup, gravel packing, fracturing, or the like. The stabilizer can continue to inhibit fines migration in the treatment zone even after an aqueous fluid without the stabilizer, e.g. a production fluid or injection fluid, displaces the original treatment fluid. When the stabilizer is used in a viscoelastic system (VES) with an acid blend component, the viscosity of the VES is essentially unchanged relative to the VES alone without the stabilizer.

Abstract: Delayed breakers are given that break viscoelastic surfactant fluids inside the pores of formations into which the fluids have been injected. The breakers comprise proteins, proteins that contain breakers, or cells that contain breakers. Proteins become breakers, and proteins and cells release breakers, due to a triggering mechanism that may be, for example, a change in temperature, pH, or salinity.

Abstract: A method for removing preexisting filtercake from a portion of a subterranean formation penetarted 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: Delayed breakers are given that break viscoelastic surfactant fluids inside the pores of formations into which the fluids have been injected. The breakers comprise proteins, proteins that contain breakers, or cells that contain breakers. Proteins become breakers, and proteins and cells release breakers, due to a triggering mechanism that may be, for example, a change in temperature, pH, or salinity.

Abstract: Delayed breakers are given that break viscoelastic surfactant fluids inside the pores of formations into which the fluids have been injected. The breakers comprise proteins, proteins that contain breakers, or cells that contain breakers. Proteins become breakers, and proteins and cells release breakers, due to a triggering mechanism that may be, for example, a change in temperature, pH, or salinity.

Abstract: The present invention provides for an apparatus and method to displace fluids and to prevent the mixing or bypassing of fluids used in gravel pack operations. A moveable plug is used to create a physical partition between fluids.

Abstract: The present invention provides a method for gravel packing a open-hole wellbore having a filter cake, comprising pumping a gravel slurry into a first portion of an annulus between the wellbore and a screen, at a sufficient rate and pressure to form at least a first fracture and diverting the gravel slurry to a second portion of said annulus through alternate flowpaths while providing hydraulic isolation between the first and the second portion of said interval, thereby preventing flowback from said second portion to said first portion and resulting extension of the first fracture, and thereby forming a second fracture in said second portion of said interval.

Abstract: A method is given for completing an interval of an open-hole injection well penetrating a subterranean formation when the interface between the wellbore and the formation includes a zone invaded by a filter cake that includes bridging materials and other embedded solid materials. The method includes the steps of injecting a clean-up fluid and contacting it with the filtercake for a period of time sufficient to loosen some of the other solids embedded in the filter cake; removing the loosened solids by a high-rate displacement fluid containing suspending additives; and then injecting a dissolving fluid containing a diverter and an effective amount of a salt or acid capable of dissolving the bridging material.

Abstract: The present invention provides for an apparatus and method to displace fluids and to prevent the mixing or bypassing of fluids used in gravel pack operations. A moveable plug is used to create a physical partition between fluids.

Abstract: A method is disclosed for using aqueous VES-based gravel carrier fluids in gravel packing operations using screens and shunt tubes that have been run into a well completed with an oil-based mud. With this method, the previously necessary but undesirable steps of first running in a perforated liner and then displacing the oil-based mud with an aqueous-based fluid in the region to be gravel packed are both avoided while the advantages of gravel packing with an aqueous-based fluid are retained.

Abstract: A method is disclosed for using aqueous VES-based gravel carrier fluids in gravel packing operations using screens and shunt tubes that have been run into a well completed with an oil-based mud. With this method, the previously necessary but undesirable steps of first running in a perforated liner and then displacing the oil-based mud with an aqueous-based fluid in the region to be gravel packed are both avoided while the advantages of gravel packing with an aqueous-based fluid are retained.