Abstract: A method for determining characteristics of a mesoporous material using a desiccation or hydration test is disclosed. The test may involve using a test fluid and exposing sample of a core to a controlled environment, then weighing the samples. The samples may be core samples, comminuted samples, or cuttings. Utilizing the determined characteristics, properties of the mesoporous material, such as porosities, absolute permeabilities and relative permeabilities may be determined.

Abstract: A method for determining characteristics of a mesoporous material using a desiccation or hydration test is disclosed. The test may involve using a test fluid and exposing sample of a core to a controlled environment, then weighing the samples. The samples may be core samples, comminuted samples, or cuttings. Utilizing the determined characteristics, properties of the mesoporous material, such as porosities, absolute permeabilities and relative permeabilities may be determined.

Abstract: A method for determining wettability of a solid, such as a reservoir rock material includes disaggregating the material, for example by grinding and placing the disaggregated material on the surface of the fluid. The wettability is analyzed based on whether a portion of the material floats on or sinks into the fluid. The method is well suited for heterogeneous solid materials that have mixed wetting characteristics and/or have varying surface types. The fluid can be evaluated as a potential treatment fluid or a component thereof that can be used for treating the rock formation. For example, the potential treatment fluid can include a surfactant or an oxidizing agent. A simple observation can be made whether substantially all of the material placed on the surface of the fluid sinks into the fluid, or the portions of floating and sinking material can be weighed.

Abstract: A method for determining a characteristic of an underground formation with a fluid is described. The method includes providing a sample material of the underground formation; measuring the permeability and the porosity of the sample material; performing a drainage test on the sample material using the fluid; estimating the threshold pressure of the sample material from the drainage test, the permeability and the porosity measurements; and determining the receding contact angle of the fluid on the sample material from the threshold pressure. The sample material can be disaggregated material.

Abstract: A method for determining a characteristic of an underground formation with a fluid is described. The method includes providing a sample material of the underground formation; measuring the permeability and the porosity of the sample material; performing a drainage test on the sample material using the fluid; estimating the threshold pressure of the sample material from the drainage test, the permeability and the porosity measurements; and determining the receding contact angle of the fluid on the sample material from the threshold pressure. The sample material can be disaggregated material.

Abstract: A method for determining wettability of a solid, such as a reservoir rock material, is described. The method includes disaggregating the material, for example by grinding and placing the disaggregated material on the surface of the fluid. The wettability is analyzed based on whether a portion of the material floats on or sinks into the fluid. The method is well suited for heterogeneous solid materials that have mixed wetting characteristics and/or have varying surface types. The fluid can be evaluated as a potential treatment fluid or a component thereof that can be used for treating the rock formation. For example, the potential treatment fluid can include a surfactant or an oxidizing agent. A simple observation can be made whether substantially all of the material placed on the surface of the fluid sinks into the fluid, or the portions of floating and sinking material can be weighed.

Abstract: A method of determining wettability of a rock sample, such as from a core sample is described. The sample is preferably crushed or comminuted to a particulate size where micro fractures have been eliminated, but where the particles are still large enough to represent the native rock matrix and texture. The comminuted core sample is exposed to a test fluid for a given period of time. The rock sample can be split into many separate aliquots, and a series of tests is performed using a series of different fluids and/or the same fluid for different exposure times. The excess test fluid residing on the surfaces of sample particles is removed. The test fluid imbibed into the interior of the particulate sample is then measured. The test fluid can be, for example, water, a non-aqueous fluid, and/or a solution of miscible solvents. The technique used to measure the imbibed fluid depends on the solvent (imbibing fluid) being studied.

Abstract: A method for determining a characteristic of an underground formation with a fluid is described. The method includes providing a sample material of the underground formation; measuring the permeability and the porosity of the sample material; performing a drainage test on the sample material using the fluid; estimating the threshold pressure of the sample material from the drainage test, the permeability and the porosity measurements; and determining the receding contact angle of the fluid on the sample material from the threshold pressure. The sample material can be disaggregated material.

Abstract: A method of treating a subterranean formation penetrated by a wellbore to mitigate the production of unwanted fluids from the wellbore is carried out by forming a treatment fluid containing at least one of an oil-wetting or water-repelling surfactant and a carrier fluid. The treatment fluid is then introduced into the wellbore. The treatment or treatments may be performed remedially or prophylacticaly. The treatment may include the completion and production of zones containing the undesirable fluid(s) and the deliberate formation of cones therein.

Abstract: Recovery of hydrocarbon fluid from low permeability sources enhanced by introduction of a treating fluid is described. The treating fluid may include one or more constituent ingredients designed to cause displacement of hydrocarbon via imbibition. The constituent ingredients may be determined based on estimates of formation wettability. Further, contact angle may be used to determine wettability. Types and concentrations of constituent ingredients such as surfactants may be determined for achieving the enhanced recovery of hydrocarbons. The selection can be based on imbibition testing on material that has been disaggregated from the source formation.

Abstract: A method of treating a subterranean formation penetrated by a wellbore to mitigate the production of unwanted air from the wellbore is carried out by forming a treatment fluid containing a water-wetting surfactant and a carrier fluid. The treatment fluid is then introduced into the wellbore. The treatment or treatments may be performed remedially or prophylacticaly. The treatment may include the completion and production of zones containing the undesirable air and the deliberate formation of cones therein.

Abstract: Recovery of hydrocarbon fluid from low permeability sources is enhanced by introduction of a treating fluid. The treating fluid may include one or more constituent ingredients designed to cause displacement of hydrocarbon via imbibition. The constituent ingredients may be determined based on estimates of formation wettability. Further, contact angle may be used to determine wettability. Types and concentrations of constituent ingredients such as surfactants may be determined for achieving the enhanced recovery of hydrocarbons.

Abstract: A method is given for treating a wellbore to increase the production of hydrocarbons from a subterranean formation penetrated by a wellbore, involving a period of injecting into the formation an aqueous injection fluid having a different chemical potential than the aqueous fluid in the formation. If there is water blocking, an osmotic gradient is deliberately created to cause flow of water into the injected fluid; hydrocarbon is then produced by imbibition. If the pore pressure in the water-containing pores in the formation is too low, an osmotic gradient is deliberately created so that water flows from the injected fluid into the water-containing pores, increasing the pore pressure and facilitating hydrocarbon production by imbibition. The method may be repeated cyclically. A semipermeable membrane may be created to enhance the osmosis. Wetting agents may be used to influence imbibition.

Abstract: A method of treating a subterranean formation penetrated by a wellbore to mitigate the production of unwanted air from the wellbore is carried out by forming a treatment fluid containing a water-wetting surfactant and a carrier fluid. The treatment fluid is then introduced into the wellbore. The treatment or treatments may be performed remedially or prophylacticaly. The treatment may include the completion and production of zones containing the undesirable air and the deliberate formation of cones therein.

Abstract: A method of treating a subterranean formation penetrated by a wellbore to mitigate the production of unwanted fluids from the wellbore is carried out by forming a treatment fluid containing at least one of an oil-wetting or water-repelling surfactant and a carrier fluid. The treatment fluid is then introduced into the wellbore. The treatment or treatments may be performed remedially or prophylacticaly. The treatment may include the completion and production of zones containing the undesirable fluid(s) and the deliberate formation of cones therein.

Abstract: A well treatment fluid composition that comprises a carrier fluid and an amphoteric surfactant, and optionally a viscosifying agent and proppant, is well suited for use in fracturing coal beds to stimulate methane production. The composition preferably is a foam that comprises a gas such as nitrogen or air. Preferably, the surfactant has the formula R—NH2—(CH2)n—C(O)OX wherein R is a saturated or unsaturated alkyl group having from 6-20 carbon atoms, n is from 2-6, and X is hydrogen or a salt forming cation.

Abstract: A well treatment fluid composition that comprises a carrier fluid and an amphoteric surfactant, and optionally a viscosifying agent and proppant, is well suited for use in fracturing coal beds to stimulate methane production. The composition preferably is a foam that comprises a gas such as nitrogen or air.

Abstract: A well treatment fluid composition that comprises a carrier fluid and an amphoteric surfactant, and optionally a viscosifying agent and proppant, is well suited for use in fracturing coal beds to stimulate methane production. The composition preferably is a foam that comprises a gas such as nitrogen or air. Preferably, the surfactant has the formula R—NH2—(CH2)n—C(O)OX wherein R is a saturated or unsaturated alkyl group having from 6-20 carbon atoms, n is from 2-6, and X is hydrogen or a salt forming cation.

Abstract: Methods are provided for increasing the production of hydrocarbons from shaly formations that contain adsorbed condensed hydrocarbon gases by treating such formations with dewatering compositions comprising surfactants that cause the surfaces of the formation to be or to remain oil-wet. The methods may be used in stimulation (acidizing or acid fracturing or hydraulic fracturing), remediation or workover, and in enhancing flow from natural fractures or from unstimulated formations.

Abstract: A well treatment fluid composition that comprises a carrier fluid and an amphoteric surfactant, and optionally a viscosifying agent and proppant, is well suited for use in fracturing coal beds to stimulate methane production. The composition preferably is a foam that comprises a gas such as nitrogen or air.