Abstract: An aqueous composition includes an acid, or an ammonium or salt thereof; a hydrogen fluoride (HF) source; and a fluoride scale inhibitor. Various methods include providing the aqueous composition and performing a treatment operation using the aqueous composition.

Abstract: Stimulation treatments are designed and performed in a manner that takes into account radial acid flow into the formation. A reservoir core plug is selected and a liner core flow test is performed. The core flow test comprises measuring a flowing fraction, injecting into the core plug a treatment volume of at least one candidate stimulation fluid at an injection rate at reservoir conditions, and measuring an effective reaction rate constant. The linear flow data are then scaled to radial flow. A skin, an acid concentration at a wormhole tip and a fluid velocity at a wormhole tip are calculated. A stimulation treatment is then performed. The method can also be performed on analog cores. The stimulation treatment may be matrix acidizing, fracture acidizing or acidizing natural fractures.

Abstract: Stimulation treatments are designed and performed in a manner that takes into account radial acid flow into the formation. A reservoir core plug is selected and a liner core flow test is performed. The core flow test comprises measuring a flowing fraction, injecting into the core plug a treatment volume of at least one candidate stimulation fluid at an injection rate at reservoir conditions, and measuring an effective reaction rate constant. The linear flow data are then scaled to radial flow. A skin, an acid concentration at a wormhole tip and a fluid velocity at a wormhole tip are calculated. A stimulation treatment is then performed. The method can also be performed on analog cores. The stimulation treatment may be matrix acidizing, fracture acidizing or acidizing natural fractures.

Abstract: Matrix acidizing treatment are designed and performed in a manner that takes into account radial acid flow into the formation. Subterranean well characteristics are determined (e.g., mineralogical and petrophysical characteristics). One of more candidate acids is selected. A linear pore volume of acid to breakthrough (PVBT) curve is generated for each candidate acid. The linear PVBT curves are modified to account for radial acid flow. The optimal acid is selected by considering wormhole development and cost. An initial acid pumping schedule is generated for the formation to be acidized, including the optimal acid, the treatment volume and the injection rate. Computer software is used to consider the subterranean well characteristics, simulate the initial acid pumping schedule and compare results with the radial PVBT curve. The initial schedule is modified until the results are consistent with the radial PVBT curve. An acidizing treatment is then performed.

Abstract: Stimulation treatments are designed and performed in a manner that takes into account radial acid flow into the formation. A reservoir core plug is selected and a liner core flow test is performed. The core flow test comprises measuring a flowing fraction, injecting into the core plug a treatment volume of at least one candidate stimulation fluid at an injection rate at reservoir conditions, and measuring an effective reaction rate constant. The linear flow data are then scaled to radial flow. A skin, an acid concentration at a wormhole tip and a fluid velocity at a wormhole tip are calculated. A stimulation treatment is then performed. The method can also be performed on analog cores. The stimulation treatment may be matrix acidizing, fracture acidizing or acidizing natural fractures.

Abstract: Matrix acidizing treatment are designed and performed in a manner that takes into account radial acid flow into the formation. Subterranean well characteristics are determined (e.g., mineralogical and petrophysical characteristics). One of more candidate acids is selected. A linear pore volume of acid to breakthrough (PVBT) curve is generated for each candidate acid. The linear PVBT curves are modified to account for radial acid flow. The optimal acid is selected by considering wormhole development and cost. An initial acid pumping schedule is generated for the formation to be acidized, including the optimal acid, the treatment volume and the injection rate. Computer software is used to consider the subterranean well characteristics, simulate the initial acid pumping schedule and compare results with the radial PVBT curve. The initial schedule is modified until the results are consistent with the radial PVBT curve. An acidizing treatment is then performed.

Abstract: In one aspect, methods may include quantifying a pore-scale heterogeneity of a porous medium; determining an adjusted pore volume to breakthrough based on the pore scale heterogeneity determined; and designing a stimulating fluid treatment for the porous medium. Other aspects may include the development of a wellbore stimulation methodology that allows stimulation fluid breakthrough curves of differing formation samples to be plotted as a single curve that accounts for the varied pore structure of the respective samples.

Abstract: A well stimulation modeling method and simulation model for modeling a stimulation treatment involving a chemical reaction between a treatment fluid and a porous medium, such as acid treatment of a carbonate formation. In a wormhole initiation stage or mode, the medium of the cells having a solid saturation above a respective critical solid saturation is comprised of matrix material behaving as a single permeability, single porosity system; and in a wormhole growth stage or mode, the cells having a solid saturation equal to or less than the respective critical sold saturation comprise two different interconnected media, the matrix material and a wormhole material, defined to include wormhole-forming material as well as mature wormholes, having fluid mobility as a function of the solid saturation.

Abstract: Performing of a chemical treatment of a near wellbore area may include extraction of a core sample representing a portion of a near wellbore area, obtaining a three-dimensional (3D) pore scale model of a core sample, determination of composition of a core sample, generation scenarios of chemical treatment that each include chemical agent, determination of rates of reaction between mineral comprising core sample and treatment fluids, determination of qualitative and quantitative composition of reaction system in equilibrium, simulation of chemical treatment process using 3D model of a core sample and data on chemical reactions between minerals and treatment fluids, analysis of the chemical treatment influence on transport properties of a core sample, selection of optimal treatment scenario. Further, an operation is performed using the selected treatment scenario.

Abstract: Methods of well treatment include modeling approaches that account for the effect of pore structure during well stimulation treatments. In one aspect, methods may include preparing a computer model of a porous medium; simulating an injection of a fluid into the computer model of the porous medium; measuring a pore-scale heterogeneity of the computer model of the porous medium, and designing a stimulating fluid treatment for the porous medium. Other aspects may include the development of a wellbore stimulation methodology that allows stimulation fluid breakthrough curves of differing formation samples to be plotted as a single curve that accounts for the varied pore structure of the respective samples.

Abstract: A technique enables stimulation of a subterranean formation. A reactive fluid is delivered downhole into a wellbore. The reactive fluid is under sufficient pressure downhole to create a jet of the reactive fluid that is directed at a specific treatment section. The jet is maintained until a localized region of enhanced permeability is created. One or more jets can be created or moved to treat a plurality of low permeability zones.

Abstract: Aqueous compositions contain hydrochloric acid at a concentration between 8 wt % and 28 wt % inclusive. The amino acid; hydrochloric acid mole ratio may be between 0.2 and 1.5. Sufficient water is present to dissolve the hydrochloric acid and the amino acid. Such compositions have utility as retarders for acid compositions employed in the stimulation of subterranean formations. Slowing the reaction between the acid and formation helps maximize formation permeability and productivity.

Abstract: Aqueous compositions contain hydrochloric acid at a concentration between 8 wt % and 28 wt % inclusive. The amino acid; hydrochloric acid mole ratio may be between 0.2 and 1.5. Sufficient water is present to dissolve the hydrochloric acid and the amino acid. Such compositions have utility as retarders for acid compositions employed in the stimulation of subterranean formations. Slowing the reaction between the acid and formation helps maximize formation permeability and productivity.

Abstract: An aqueous solution includes HCl present in an amount exceeding 37% by weight. The solution further includes a fixing agent that is urea and/or a urea derivative. The fixing agent is present in the solution in a molar ratio of between 0.25 and 2.0 of fixing agent to HCl, inclusive.

Abstract: An aqueous solution includes HCl present in an amount exceeding 37% by weight. The solution further includes a fixing agent that is urea and/or a urea derivative. The fixing agent is present in the solution in a molar ratio of between 0.25 and 2.0 of fixing agent to HCl, inclusive.

Abstract: Oilfield treatment compositions contain water, hydrochloric acid at a concentration between 15 wt % and 45.7 wt % and a first and second fixing agent. The first fixing agent comprises urea, a urea derivative or both. The second fixing agent may be a mixture or amines and alcohols. These compositions provide corrosion inhibition when exposed to steel. The compositions may also contain an inhibitor aid.

Abstract: Oilfield treatment compositions contain water, hydrochloric acid at a concentration between 15 wt % and 45.7 wt % and a first and second fixing agent. The first fixing agent comprises urea, a urea derivative or both. The second fixing agent may be a mixture or amines and alcohols. These compositions provide corrosion inhibition when exposed to steel. The compositions may also contain an inhibitor aid.

Abstract: In one aspect, methods may include quantifying a pore-scale heterogeneity of a porous medium; determining an adjusted pore volume to breakthrough based on the pore scale heterogeneity determined; and designing a stimulating fluid treatment for the porous medium. Other aspects may include the development of a wellbore stimulation methodology that allows stimulation fluid breakthrough curves of differing formation samples to be plotted as a single curve that accounts for the varied pore structure of the respective samples.

Abstract: Methods of well treatment include modeling approaches that account for the effect of pore structure during well stimulation treatments. In one aspect, methods may include preparing a computer model of a porous medium; simulating an injection of a fluid into the computer model of the porous medium; measuring a pore-scale heterogeneity of the computer model of the porous medium, and designing a stimulating fluid treatment for the porous medium. Other aspects may include the development of a wellbore stimulation methodology that allows stimulation fluid breakthrough curves of differing formation samples to be plotted as a single curve that accounts for the varied pore structure of the respective samples.

Abstract: A well stimulation modeling method and simulation model for modeling a stimulation treatment involving a chemical reaction between a treatment fluid and a porous medium, such as acid treatment of a carbonate formation. In a wormhole initiation stage or mode, the medium of the cells having a solid saturation above a respective critical solid saturation is comprised of matrix material behaving as a single permeability, single porosity system; and in a wormhole growth stage or mode, the cells having a solid saturation equal to or less than the respective critical sold saturation comprise two different interconnected media, the matrix material and a wormhole material, defined to include wormhole-forming material as well as mature wormholes, having fluid mobility as a function of the solid saturation.