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: Oilfield treatment compositions contain water, hydrochloric acid and urea. The urea and water may be present at a urea/water weight ratio between 0.8 and 12.0, and the hydrochloric acid and urea may be present at a urea/hydrochloric acid molar ratio between 0.1 and 0.5. The compositions are present as one liquid phase. The volumes of the compositions are substantially higher than those of the water volumes; consequently, the amount of water necessary to perform various well-service operations is lower.

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 fixing agent. The first fixing agent comprises urea, a urea derivative or both. The molar ratio between the first fixing agent and water may be higher than or equal to 0.5, and urea is the dominant solvent species in the compositions. In these compositions the first fixing agent provides corrosion inhibition when exposed to steel. The compositions may also contain a second fixing agent and an inhibitor aid.

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: Rapidly pulsed injection fracture acidizing. A method comprises rapidly pulsed injection of a high reactivity fracture treatment fluid mode or substage alternated with one or more low reactivity treatment fluid modes or substages.

Abstract: A method of treating a formation includes preparing an aqueous solution having HCl in an amount between greater than 15% and 45.7% by weight, inclusive. The prepared aqueous solution includes a fixing agent (FA) present in a molar ratio of FA:HCl between 0.15 and 2.5 inclusive, where the FA is urea and/or a urea derivative, and further includes water present in an amount sufficient to dissolve the HCl and the FA. The aqueous solution includes substantially no polysaccharides. The method further includes providing an oilfield treatment fluid including the aqueous solution to a high pressure pump operating the high pressure pump to treat a wellbore and/or the formation fluidly coupled to the wellbore.

Abstract: A method includes providing an oilfield treatment fluid including an aqueous HCl solution having greater than 15% HCl by weight, and a fixing agent (FA) in a molar ratio of FA:HCl of between 0.5 and 2.5 inclusive. The FA is urea and/or a urea derivative. The oilfield treatment fluid further includes a viscosifying agent that is not a plant-based polysaccharide gum. The method further includes providing the oilfield treatment fluid to a high pressure pump, and operating the high pressure pump to treat a formation fluidly coupled to a wellbore.

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: A method of determining parameters relating to the flow performance of subterranean sources is described using the steps of measuring a total flow rate and pressure at a reference datum for at least two different flow rates, allocating the flow from each of the sources using identified concentrations of characteristic components, and using the total flow rate, pressure and the allocation to determine selective inflow performance relationships for each source.

Abstract: A method and apparatus to treat a subterranean formation comprising a wellbore including introducing a tool to a wellbore in a region of low permeability or damage, treating the region of low permeability or damage with a fluid, simultaneously measuring a fluid pressure drop and volume of fluid flow in a particular region, and moving the tool to another region. A method and apparatus to treat a subterranean formation comprising a wellbore including introducing to a wellbore a tool in a region of low permeability or damage, treating the region of low permeability or damage with a fluid, introducing a diversion agent, and moving the tool to another region wherein the fluid comprises a tracer.

Abstract: A method for determining flow distribution in a formation having a wellbore formed therein includes the steps of positioning a sensor within the wellbore, wherein the sensor generates a feedback signal representing at least one of a temperature and a pressure measured by the sensor, injecting a fluid into the wellbore and into at least a portion of the formation adjacent the sensor, shutting-in the wellbore for a pre-determined shut-in period, generating a simulated model representing at least one of simulated temperature characteristics and simulated pressure characteristics of the formation during the shut-in period, generating a data model representing at least one of actual temperature characteristics and actual pressure characteristics of the formation during the shut-in period, wherein the data model is derived from the feedback signal, comparing the data model to the simulated model, and adjusting parameters of the simulated model to substantially match the data model.

Abstract: A method of determining a concentration of a component in a flow from a single source or layer contributing to a total flow using the steps of measuring the total flow rate at various depths and sampling the total flow at a depth between two successive sources, measuring a total concentration of one or more flow components within the total flow, repeating the measuring of the total flow rate, the sampling and total concentration in further intervals separating other pairs of successive sources, and determining the concentration of at least one component by solving a system of mass balance equations representing the total flow of the flow components at each sampling depth.

Abstract: In a method of treating a sandstone-containing formation penetrated by a wellbore, a treatment fluid comprising an aqueous fluid containing a Bronsted acid, a hydrogen fluoride source and an organic acid or salt thereof that is substantially soluble in the aqueous fluid is formed. The treatment fluid contains less than about 2% of fluoride (F?) by weight of the fluid and from 2% or less of sodium (Na+) by weight of the fluid. The treatment fluid is introduced into the formation through the wellbore as a single-stage without introducing an acid-containing fluid preflush into the formation prior to introducing the treatment fluid.

Abstract: In a method of treating a sandstone-containing formation penetrated by a wellbore, a treatment fluid comprising an aqueous fluid containing a Bronsted acid, a hydrogen fluoride source and an organic acid or salt thereof that is substantially soluble in the aqueous fluid is formed. The treatment fluid contains less than about 2% of fluoride (F?) by weight of the fluid and from 2% or less of sodium (Na+) by weight of the fluid. The treatment fluid is introduced into the formation through the wellbore as a single-stage without introducing an acid-containing fluid preflush into the formation prior to introducing the treatment fluid.

Abstract: Methods and systems are described for stimulating a subterranean hydrocarbon-bearing reservoir, one method comprising contacting the formation with a treating fluid, and monitoring the movement of the treating fluid in the reservoir by providing one or more sensors for measurement of temperature and/or pressure which is disposed on a support adapted to maintain a given spacing between the sensors and the fluid exit. In some embodiments the support is coiled tubing.

Abstract: Subterranean formation treatment methods incorporating a rheology model which enables prediction of fluid rheology properties during a treatment operation, where the foundation of the model is a description of the reaction chemistry which describes how the number of crosslinks and broken polymer linkages develops in time under the influence of crosslinkers, breakers, and/or thermally induced effects and pressure effects. In one aspect, when used as a tool for simulating the fluid viscosity, the model can help optimizing the fluid design and optional breaker schedule for a hydraulic fracturing treatment.

Abstract: A method of testing the performance of a stimulation fluid by placing a sample of the stimulation fluid or a precursor thereof into the body of a downhole tool, positioning the tool in juxtaposition with a rock face at a downhole location, forming a sealing contact between the rock face and the tool; and injecting the sample into the rock face while monitoring pressure and/or flow rates during the injection of the sample into and/or production of formation fluid from the rock face to derive a measure of the effectiveness of the stimulation fluid in creating openings in the rock face.

Abstract: A method for determining flow distribution in a formation having a wellbore formed therein includes the steps of positioning a sensor within the wellbore, wherein the sensor generates a feedback signal representing at least one of a temperature and a pressure measured by the sensor, injecting a fluid into the wellbore and into at least a portion of the formation adjacent the sensor, shutting-in the wellbore for a pre-determined shut-in period, generating a simulated model representing at least one of simulated temperature characteristics and simulated pressure characteristics of the formation during the shut-in period, generating a data model representing at least one of actual temperature characteristics and actual pressure characteristics of the formation during the shut-in period, wherein the data model is derived from the feedback signal, comparing the data model to the simulated model, and adjusting parameters of the simulated model to substantially match the data model.

Abstract: A method of method of determining relative contributions of two or more producing subterranean sources to a total flow is described using the steps of selecting a subset from a set of identifiable components in the total flow and using the subset to determine the relative contributions of two or more producing subterranean sources, wherein the subset is selected based on the sensitivity of the determination step to errors in the measurement of concentrations of said identifiable components.