Abstract:
Embodiments of the present invention relate to heat transfer fluids (e.g. molten-salt) as a thermal buffer for heating, by thermal energy derived from wind-generated electricity, at least one of (i) a subsurface hydrocarbon-containing formation or (ii) a bed of hydrocarbon-containing rocks. During times when 5 wind is plentiful, wind electricity is used to heat the heat transfer fluid - e.g. by means of an electrically resistive heater immersed in the heat transfer fluid. At any time, thermal energy from the wind electricity may be transferred to the hydrocarbon-containing rocks or subsurface formation by the heat transfer fluid. In some embodiments, the fluid is 10 heated both by wind-generated electricity and by solar radiation. Some embodiments relate to a subsurface molten salt heater (e.g. powered by wind-generated electricity) having a non-thermally insulation portion through which molten salt flows. The heater is configured to maintain a temperature of the circulating molten salt, throughout the substantially non-thermally-insulated portion, at a temperature significantly above a 15 melt temperature of the molten salt.
Abstract:
Embodiments of the present invention relates to a pyrolysis-derived thiophenic composition having a high concentration of C1 and/or C2 and/or C3 alkylthiophenes. Preferably, the composition is derived from pyrolysis (e.g. by slow, low-temperature pyrolysis) of type IIs kerogen (e.g. of a kerogenous chalk). In some embodiments, the thiophenic composition may be used as an enhanced oil recovery (EOR) fluid. Some advantages of the presently-disclosed alkylthiophene-rich enhanced oil recovery (EOR) fluids are that (i) the alkyl-thiophene fluids have excellent solvency for heavy hydrocarbons, (ii) alkyl-thiophene fluids are insoluble in water; (iii) it is possible to blend the alkyl-thiophene fluids to a density of about 1.0 g/cc which matches extra heavy oils and bitumens and water; (iv) a boiling point of alkyl-thiophenes exceeds that of water, making it possible to inject heated EOR fluid and create steam in situ for steam distillation. Methods of use of the EOR fluid are disclosed herein.
Abstract:
Some embodiments relate to a method for producing, from sulfur-rich type IIs kerogen, a sweetened synthetic crude having a sulfur concentration of at most 1% wt/wt, a nitrogen concentration of at most 0.2% wt/wt and an API gravity of at least 30°. Hydrotreating is performed under only low-severity conditions of at most about 350 degrees Celsius and a maximum pressure of at most 120 atmospheres. In some embodiments, the feedstock to the hydrotreater comprises hydrocarbon pyrolysis liquids generated primarily by low temperature pyrolysis of the sulfur-rich type IIs kerogen. For example, the feedstock may be rich in easier-to-hydrotreat heterocyclic species. In some embodiments, it is possible to optimize the pyrolysis process by monitoring relative concentrations of the easier-to- hydrotreat heterocyclics and the harder-to-treat heterocyclics.
Abstract:
Embodiments of the present invention relate to heater patterns and related methods of producing hydrocarbon fluids from a subsurface hydrocarbon-containing formation (for example, an oil shale formation) where a heater cell may be divided into nested inner and outer zones. Production wells may be located within one or both zones. In the smaller inner zone, heaters may be arranged at a relatively high spatial density while in the larger surrounding outer zone, a heater spatial density may be significantly lower. Due to the higher heater density, a rate of temperature increase in the smaller inner zone of the subsurface exceeds that of the larger outer zone, and a rate of hydrocarbon fluid production ramps up faster in the inner zone than in the outer zone. In some embodiments, a ratio between a half-maximum sustained production time and a half-maximum rise time of a hydrocarbon fluid production function is relatively large.
Abstract:
Methods for assessing a temperature in an opening in a subsurface formation are described herein. A method may include assessing one or more dielectric properties along a length of an insulated conductor located in the opening and assessing one or more temperatures along the length of the insulated conductor based on the one or more assessed dielectric properties.
Abstract:
Systems and methods for treating a subsurface formation are described herein. A system for treating a subsurface formation may include a plurality of wellbores in the formation. The system may include at least one heater positioned in at least two of the wellbores. The system may include a self-regulating nuclear reactor. The self-regulating nuclear reactor may function to provide energy to at least one of the heaters to raise the temperature of the formation to temperatures that allow for hydrocarbon production from the formation. A temperature of the self-regulating nuclear reactor may be controlled by controlling a pressure of hydrogen supplied to the self-regulating nuclear reactor. The pressure may be regulated based upon formation conditions.
Abstract:
Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.
Abstract:
Embodiments of the present invention relate to heater patterns and related methods of producing hydrocarbon fluids from a subsurface hydrocarbon-containing formation (for example, an oil shale formation) where a heater cell may be divided into nested inner and outer zones. Production wells may be located within one or both zones. In the smaller inner zone, heaters may be arranged at a relatively high spatial density while in the larger surrounding outer zone, a heater spatial density may be significantly lower. Due to the higher heater density, a rate of temperature increase in the smaller inner zone of the subsurface exceeds that of the larger outer zone, and a rate of hydrocarbon fluid production ramps up faster in the inner zone than in the outer zone. In some embodiments, a ratio between a half-maximum sustained production time and a half-maximum rise time of a hydrocarbon fluid production function is relatively large.
Abstract:
Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.
Abstract:
A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300°C.