The invention relates to an inverse polymer emulsion having the particular feature of auto-inverting without any need for the use of an inverting agent and containing a polymer of at least one water-soluble monomer and at least one LCST macromonomer. The invention also relates to the use of the inverse emulsion in the fields of the oil and gas industry, water treatment, slurry treatment, paper manufacturing, construction, mining, cosmetics, textiles, detergents or agriculture.

The invention relates to an inverse polymer emulsion having the particular feature of auto-inverting without any need for the use of an inverting agent and containing a polymer of at least one water-soluble monomer and at least one LCST macromonomer. The invention also relates to the use of the inverse emulsion in the fields of the oil and gas industry, water treatment, slurry treatment, paper manufacturing, construction, mining, cosmetics, textiles, detergents or agriculture.

Techniques for determining one or more hydrocarbon sweet spots include generating a three-dimensional (3D) simulation model of a hydrocarbon reservoir in a subterranean formation; executing a gas winnowing process to the 3D simulation model; applying one or more geomechanical restraints to the 3D simulation model; activating one or more energy simulation parameters with the 3D simulation model; applying a total dynamic productivity index (TDPI) process to the 3D simulation model to generate at least one 3D index that includes one or more hydrocarbon sweet spots; and generating a graphical representation of the generated 3D index for presentation on a graphical user interface (GUI) to a user.

A variety of methods, systems, and compositions are disclosed, including, in one embodiment, method of scale inhibition including: introducing a treatment fluid comprising a brine, a scale inhibitor in neutralized form, and a thermally activated acid precursor through a wellbore and into a producing formation; wherein the thermally activated acid precursor is heated to release an acid that enhances miscibility of the scale inhibitor in the brine.

Some reservoirs have tight oil formations, such as the Changqing reservoir. The surfactant polymer flooding and low tension gas flooding are two potential chemical flooding methods for use in tight oil formations. In these methods, an oil displacement agent, or surfactant, is added. Nonionic surfactants with extended chains (by propylene oxide and ethylene oxide) from dialkyl alcohols or dialkyl amines were tested. A synergistic blend of surfactants was developed between the nonionic surfactants and anionic surfactants that lowers interfacial tension and improves surfactant solubility in water and oil.

Some reservoirs have tight oil formations, such as the Changqing reservoir. The surfactant polymer flooding and low tension gas flooding are two potential chemical flooding methods for use in tight oil formations. In these methods, an oil displacement agent, or surfactant, is added. Nonionic surfactants with extended chains (by propylene oxide and ethylene oxide) from dialkyl alcohols or dialkyl amines were tested. A synergistic blend of surfactants was developed between the nonionic surfactants and anionic surfactants that lowers interfacial tension and improves surfactant solubility in water and oil.

A conformance improvement method involves injecting, via an injection well, a first water slug into a subsurface reservoir. A second water slug is injected, via the injection well, into the subsurface reservoir. The first and second water slugs have different viscosities, at least one of the first and second water slugs includes a surfactant, and the first and second water slugs combine with oil in the subsurface reservoir to form a microemulsion in a layer of the subsurface reservoir. A fluid is injected, via the injection well, into the subsurface reservoir. Oil is collected, via a production well, from the subsurface reservoir. The injected fluid causes the oil to move into the production well.

A conformance improvement method involves injecting, via an injection well, a first water slug into a subsurface reservoir. A second water slug is injected, via the injection well, into the subsurface reservoir. The first and second water slugs have different viscosities, at least one of the first and second water slugs includes a surfactant, and the first and second water slugs combine with oil in the subsurface reservoir to form a microemulsion in a layer of the subsurface reservoir. A fluid is injected, via the injection well, into the subsurface reservoir. Oil is collected, via a production well, from the subsurface reservoir. The injected fluid causes the oil to move into the production well.

Techniques including methods, apparatus and computer program products are disclosed for determining an amount of hydrocarbon recoverable from porous reservoir rock by a miscible gas flood. The techniques include retrieve a representation of a physical porous reservoir rock sample (porous reservoir rock), the representation including pore space and grain space data corresponding to the porous reservoir rock, subsequent to an execution of a multiphase flow simulation to obtain predictions of flow behavior of oil in the presence of a waterflood of the porous reservoir rock, locate substantially immobile oil blobs or patches in the retrieved representation of the porous reservoir rock; and for N number of substantially immobile oil blobs or patches (blobs), evaluate changes in mobility of the blobs for two or more iterations an effort level for of a given EOR technique, with a first one of the two or more iterations expending a first level of effort and a second one of the two or more iterations expending a second, higher level of effort, to estimate an amount of change in mobilization of the blob between the first and the second iterations for the given EOR technique.

Techniques including methods, apparatus and computer program products are disclosed for determining an amount of hydrocarbon recoverable from porous reservoir rock by a miscible gas flood. The techniques include retrieve a representation of a physical porous reservoir rock sample (porous reservoir rock), the representation including pore space and grain space data corresponding to the porous reservoir rock, subsequent to an execution of a multiphase flow simulation to obtain predictions of flow behavior of oil in the presence of a waterflood of the porous reservoir rock, locate substantially immobile oil blobs or patches in the retrieved representation of the porous reservoir rock; and for N number of substantially immobile oil blobs or patches (blobs), evaluate changes in mobility of the blobs for two or more iterations an effort level for of a given EOR technique, with a first one of the two or more iterations expending a first level of effort and a second one of the two or more iterations expending a second, higher level of effort, to estimate an amount of change in mobilization of the blob between the first and the second iterations for the given EOR technique.