A method and system are shown that conditions an underground reservoir by flooding the reservoir with a heated fluid to transfer heat to the underground reservoir and cause oil and gas to increase flow during recovery from the underground reservoir, wherein the fluid is heated by heat from a geothermal well, or heated by heat generated by burning gas recovered from the underground reservoir, or heated by heat from both a geothermal well and heat generated by burning gas recovered from the underground reservoir, and recovering the oil and gas with the increased flow.

System includes one or more processors that are configured to perform iterations of the following until a predetermined condition is satisfied. The one or more processors are configured to select a modified trial schedule. The modified trial schedule is selected based on initial fluid-extraction data and initial trial schedules and, if available, prior modified trial schedules and prior modified fluid-extraction data from prior iterations. The one or more processors are configured to receive modified fluid-extraction data generated by execution of the modified trial schedule with a designated model of the reservoir. The one or more processors are also configured to update the surrogate model with the modified fluid-extraction data and the modified trial schedule. For at least a plurality of the iterations, the modified trial schedule is selected, at least in part, to reduce uncertainty in a sample space as characterized by the surrogate model.

The present invention is a process for the thermobaric production of hydrocarbons from natural reservoirs through conventional wells. The hydrocarbons are converted into corresponding vapor phase fractions in the downhole. Such conversion is accomplished through the use of a combination of gasifying agents, heated atmospheric air, and steam—all pumped into the downhole. Temperature and pressure gradients that develop in the reservoir lead to disintegration of low-porosity rock and decompaction of impermeable rock. The vapor phase fractions are recovered at the well head and condensed on-site into high quality liquid and gaseous products.

A pressure-up blow-down method for recovering oil from an underground hydrocarbon formation, comprising the steps of: injecting an injection fluid into alternatingly-spaced multiple-induced fractures which extend radially outwardly and along a horizontal portion of a wellbore in the formation; ceasing injection of said injection fluid; recovering to surface oil which flows from remaining of the multiple induced fractures into the wellbore; and successively repeating the foregoing steps one or more times. Gas preferentially is initially used as the injection fluid and after one successive iteration water is then used. A sliding sleeve or sleeves which may be selectively slid open and closed within the wellbore in accordance with the method to allow and prevent, at various time periods in the method, fluid communication with fluid injection fractures and oil production fractures.

Methods for enhanced oil recovery (EOR) are disclosed that involve removal of oil from a reservoir that has an injection well, a producing well, and a plurality of lenses that contain oil and that each span between the injection well and the producing well. One method, among others, involves recovering primary oil from a primary set of lenses via the producing well by alternating injection one or more times of water and carbon dioxide into the injection well so that the water and carbon dioxide enter the primary set in a first direction and move the primary oil in the first direction. The method further involves recovering secondary oil from a secondary set of lenses that is different than the primary set via the injection well by alternating injection one or more times of water and carbon dioxide into the producing well so that the water and carbon dioxide enter the secondary set in a second direction that is different than the first direction (e.g., opposite) and therefore move the secondary oil in the second direction.

Treatment fluids including a base fluid; and fly ash microspheres, wherein the fly ash microspheres are of a material selected from the group consisting of Class C fly ash, Class F fly ash, and any combination thereof, wherein the fly ash microspheres have a diameter in the range of from about 0.1 μηη to about 150 μηη, and wherein the fly ash microspheres are present in the treatment fluid in an amount in the range of from about 0.001 ppg to about 1 ppg of the treatment fluid.

The disclosure provides a method of treating a subterranean formation penetrated by a wellbore. The method includes introducing a gas phase gas into fractures of the subterranean formation extending from the wellbore, followed by introducing a carrier fluid into the subterranean formation under sufficient pressure to fracture a portion of the subterranean formation and release hydrocarbons from the subterranean formation. The gas phase gas occupies the fractures at a sufficient pressure to cause the carrier fluid to be diverted to additional fractures of the subterranean formation defined by the portion.

The method and the system (100) according to the invention relate to the injection of gas into an underground formation, enhanced by the simultaneous injection of liquid (IL). Mixing of the gas and the liquid can occur at different levels in the well in order to facilitate the flow and to limit the gas pressure necessary for reinjection at the wellhead. Thus, the system (100) and the method require less energy and the associated gas compression equipment is less expensive.

The invention notably applies to geothermal energy applications, underground gas storage, notably CO.sub.2, or to enhanced recovery in petroleum reservoirs.

FIG. 3a to be published.

Systems and methods for enhanced or improved oil recovery includes injecting a Y-Grade NGL enhanced oil recovery fluid through an injection well into a hydrocarbon bearing reservoir to mobilize and displace hydrocarbons. The Y-Grade NGL enhanced oil recovery fluid comprises an unfractionated hydrocarbon mixture. Simultaneously and/or subsequently, a mobility control fluid is injected into the hydrocarbon bearing formation. Hydrocarbons from the hydrocarbon bearing reservoir are produced through a production well or the same injection well.

A method for treating a hydrocarbon-containing formation includes injecting an aqueous solution that contains an alkali nitrite, an ammonium halide, and a foaming agent into the formation, injecting supercritical carbon dioxide into the formation, allowing a portion of the carbon dioxide to dissolve in the aqueous solutions, causing the alkali nitrite and ammonium halide to react and generate nitrogen gas, and allowing a foam to form by the interaction of the nitrogen gas with the foaming agent.