Abstract: A method for recovering petroleum from a formation, wherein at least two injection wells and at least one production well are in fluid communication with said formation, comprising: introducing a gaseous mixture into a first and a second injection well at a temperature and a pressure, wherein said gaseous mixture comprises steam and non-condens able gas (NCG); and recovering a fluid comprising petroleum from said production well, wherein said injection wells and a production well are horizontal wells, and wherein said first injection well is disposed 1-10 meters above said production well, and said second injection well is disposed at least 5 meters above said first injection well.

Abstract: A method of recovering resources from a resource bearing formation includes selectively injecting a fluid into the resource bearing formation through one or more injector wells, extracting a resource from the resource bearing formation through one or more production wells, receiving at a sweep pattern controller, an input from each of the one or more production wells indicating an amount of the resource extracted over a period of time, determining, in the sweep pattern controller, an adjusted sweep pattern for the formation that substantially equalizes production from each of the one or more production wells, and signaling each of the one or more injector wells, from the sweep pattern controller, to selectively inject the fluid to establish the adjusted sweep pattern in the formation.

Abstract: Techniques for recovering hydrocarbons, such as heavy hydrocarbons or bitumen, from a cellar region below a horizontal production well can include providing a cellar well section that extends from the horizontal production well into the cellar region. The horizontal production well can be part of a Steam-Assisted Gravity Drainage (SAGD) in situ recovery system, which forms a hydrocarbon depleted region and a hydrocarbon bearing cellar region. The cellar region includes hydrocarbons that have been pre-heated by SAGD operations. One or more cellar well sections are provided from the SAGD production well to extend into the cellar region, in order to form a branched production well. A pressurizing gas can be injected into the hydrocarbon depleted region from a SAGD injection well, in order to provide sufficient pressure to promote production of pre-heated hydrocarbons from the cellar region through the cellar well section.

Abstract: A method and system determines the performance index of subterranean rock. A performance index is determined for subterranean rock of an area. The area includes a well. A time period is determined during producing the well. The performance index is also determined from data of the time period from the equation PI=(q/dd)*(cum./GPI). The term PI is the performance index, and the term q is the average daily rate of the well for the time period. The term dd is the average drawdown per day of the well for the time period, and the term cum. is the cumulative production of the well for the time period. The term GPI is the gross perforated interval of the well for the time period.

Abstract: A method of evaluating a stimulation operation includes: receiving parameter information for the stimulation operation, the stimulation operation including injecting an acid stimulation fluid into an earth formation along a selected length of a borehole from a tubular disposed in the borehole; and generating, by a processor, a thermal model based on one or more energy balance equations that account for at least a first heat source and a second heat source, the first heat source expected to produce heat during the stimulation by a chemical reaction between an acid in the stimulation fluid and the formation, and the second heat source including expected geothermal heat from the formation.

Abstract: The invention is a method of evaluating a recovery potential for hydrocarbons contained in a fractured reservoir, using an enhanced recovery technique. Characteristic reservoir data, data obtained from well test results and data relative to the development conditions are acquired. A pressure gradient related to the flow of a fluid injected to improve recovery is then estimated from the previously acquired data. A recovery coefficient is calculated for the hydrocarbons initially in place in matrix blocks by estimating water saturation for a state of equilibrium of the matrix blocks. Finally, the oil recovery time under the effect of the fluid circulation in fractures is estimated by determining the required for the matrix blocks to change from the initial state to a state of equilibrium.

Abstract: A system for heating hydrocarbon resources in a subterranean formation having spaced-apart wellbores therein aligned in a plane may include radio frequency (RF) antennas to be positioned within respective ones of the spaced apart wellbores aligned in the plane. The system may also include a plurality of discrete RF sources each coupled to one of the RF antennas and configured so that the RF antennas are driven at a same frequency as each other RF antenna but at different phases.

Abstract: A method for heating a production fluid in a wellbore. The method can include heating, using a packer fluid, a working fluid flowing through a first medium disposed in a first section of the wellbore, where the first medium transfers heat from the packer fluid to the working fluid. The method can also include circulating the working fluid into a second section of the wellbore through a second medium, where the second medium transfers heat from the working fluid to the production fluid. The method can further include returning the working fluid to the first section of the wellbore through the first medium.

Abstract: An oil shale exploitation method comprises: forming a gas inlet pipeline (1) and a gas outlet pipeline (3) in an oil shale; forming a gasification channel (5) that connects the gas inlet pipeline and the gas outlet pipeline in the oil shale; feeding combustible gas and oxygen into the well through different gas inlet pipelines, and then igniting, in an aerobic environment, the combustible gas fed into the well at the lower opening of the pipeline for conveying the combustible gas, so as to heat the oil shale; and recycling through the gas outlet pipeline an oil-gas mixed product formed after thermal decomposition of kerogen in the oil shale.

Abstract: A method for developing deposits and extracting oil and gas from formations is provided including pumping electrically conductive fluid under pressure into a first heating well and a second heating well, creating an electrically conductive zone between the first heating well and the second heating well, positioning at least one first electrical current source into the first well and at least one second electrical current source into the second well such that the first and second electrical current sources come into contact with the electrically conductive fluid, applying alternating current to the at least one first electrical current source and the at least one second electrical current source, and generating an electric arc in the electrically conductive zone.

Abstract: A system and method are provided for recovering bitumen from a bitumen reserve. The method includes recovering bitumen from an alternative pay region in the bitumen reserve via gravity drainage using an inclined horizontally drilled well drilled from a drainage pit upwardly into the bitumen reserve. The drainage pit has been excavated into an area of an underlying formation that is, at least in part, adjacent to and underlying the bitumen reserve. The alternative pay region includes a region unsuitable for recovering bitumen by surface mining or by in situ recovery using wells that produce bitumen to ground level above the alternative pay region.

Abstract: The invention relates to a seismic acquisition process where multiple seismic sources are used to acquire seismic energy using encoding so that all of the sources may deliver seismic energy at the same time where the sweeps are arranged to be back to back with no listen time and wherein a pseudo listen time that is uncontaminated is created in the composite data record. After the listen time is created, the composite data may be source separated for further processing and analysis.

Abstract: A method for producing bitumen or heavy oil from a reservoir, the method comprising: defining at least one lateral section of the reservoir for placement of patterns of heater wells above a producer well; placing the producer well at a substantially centered location at or adjacent to the bottom of the reservoir within each of the lateral sections; placing a triangular pattern of heater wells above the producer well; placing a regular or non-regular pentagonal pattern of heater wells, or a portion thereof, at or above the triangular pattern of heater wells; heating the reservoir with the triangular and pentagonal patterns of heater wells to conductively heat the reservoir and reduce the viscosity of the bitumen or heavy oil; and producing bitumen or heavy oil with the producer well.

Abstract: Methods for increasing the enthalpy of a geothermal brine, methods for recovering heat enthalpy stored in a geothermal brine, and methods for the production of a heated brine from a natural geothermal reservoir are provided. The methods may be incorporated into a geosolar electric power generation project to provide a steady and flexible source of renewable energy from a geothermal heat source in combination with solar insolation.

Abstract: The invention relates to a method of managing ground water resources, where bores are used to extract ground water such as for agricultural, mining and town water supply purposes. It involves a method for managing a groundwater resource including, providing at least one production bore that is adapted to extract groundwater from an aquifer, providing at least one monitoring bore that provides a measure of the extraction capability of removing water from the aquifer, measuring the hydraulic head of groundwater in the aquifer by means of the monitoring bore, and monitoring at least one indicator of the capability of extracting groundwater from the bores. The method involves determining at least one trigger point at which further monitoring of, or action in respect of, the groundwater extraction is to be undertaken, and intervening when this trigger point is reached during groundwater extraction.

Abstract: A wellbore system and method for making viable the exploitation of oil deposits considered unviable, utilizing equipment available at the wells, wherein two wells, drilled in neighboring deposits, are connected by mechanical and hydraulic interconnection. The two wells include a first well (target well) in active production, fully equipped, and processing its production in a stationary production unit (SPU), and a second well, which is considered unviable. The second well initially appears as a pilot hole, can be used to map the reservoir of the deposit where it is located, and after the mapping procedure, its base can be cemented and abandoned. The pilot hole becomes the point of origin for drilling a horizontal lateral well in the direction of the first well, which becomes the target of the drilling and a recipient of production arising from the neighboring deposit where the second well is located.

Abstract: A ball joint 10 includes a first member 12 having a ball section 14 and a second member 15 having a socket 16. Ball section 14 is accommodated and supported inside socket 16. A pair of dies 20, 30 sandwich a wall 18 surrounding an opening 17 of the socket 16, and are configured to approach each other gradually, utilizing small repetitive vibrations that include an approaching and separating action, thereby intermittently pressing the wall in an inward radial direction. During each interval of the intermittent pressing action, a supporting and rotating device 40 rotates socket 16 (second member 15) in small increments about a central axis C2 of socket 16. Consequently, dies 20 and 30 successively press against a multitude of points on the circumference of the outer surface of wall 18 of the socket, thereby bending wall 18 inward so as to reduce the diameter thereof.

Abstract: A burner is arranged for access to a cavity in a target zone of a hydrocarbon reservoir. The burner is operated into the cavity to create and sustain hot combustion gases at a steady state for flowing into and permeating through the target zone. Water is injected into the target zone and permeates laterally therein. The hot combustion gases and the water in the target zone interact to form a steam drive front in the hydrocarbon reservoir.

Abstract: Methods and systems for enhancing recovery of hydrocarbons below a permafrost layer are provided which use a downhole combustion device to inject a heated fluid into a subterranean formation to enhance hydrocarbon recovery through viscosity reduction. The system is configured to avoid adversely thermally affecting the permafrost, which is highly undesirable. One or more heat exchangers may be used in conjunction with the combustion device to enhance heat transfer of various streams. The heat exchanger(s) mitigate the adverse effects of various streams on the permafrost by lowering the return stream temperatures, which are transported through the wellbore. A carbon dioxide capture system may be provided to recover carbon dioxide from the combustion device exhaust. Certain optional embodiments allow the amount of carbon dioxide introduced into the formation to be independently controlled to further enhance the hydrocarbon recovery.

Abstract: A system for producing hydrocarbons in situ from a heavy-oil and tar sand fixed bed, hydrocarbon deposit distributed substantially within a porous formation. The system includes at least one injection well and at least one production well drilled into the formation. A heated thermal-energy carrier fluid is circulated into the injection well and through a hydraulic fracture in the formation. The fracture is disposed between the injection well and the production well. The carrier fluid mobilizes hydrocarbons in situ by heating the hydraulic fracture and producing mobilized hydrocarbons through the production well. The hydrocarbons are then divided into at least two fluid fractures having differing chemical compositions.

Abstract: Gas from a tight gas formation may be produced using a drain hole having a juncture to a main wellbore and a terminal end at a depth higher than the juncture. The terminal end may be positioned in the tight gas formation.

Abstract: Described embodiments relate to methods, systems and infrastructure for flow manipulation within a porous volume. Some embodiments relate to a method of subsurface flow manipulation, comprising: providing fluid at a first subsurface location adjacent to or in a subsurface volume through which the fluid is to pass; providing first suction at a second subsurface location adjacent to or in the subsurface volume to extract fluid from the subsurface volume, the second subsurface location being located across at least part of the subsurface volume from the first subsurface location; providing fluid at a third subsurface location spaced from the first subsurface location and adjacent to or in the subsurface volume; and providing second suction at the first, second or a fourth subsurface location adjacent to the subsurface volume to extract fluid from the subsurface volume.

Abstract: In selected aspects, the present invention provides methods and systems for recovering hydrocarbons from a reservoir involving gravity-dominated recovery processes, such as steam assisted gravity drainage (SAGD). Aspects of the invention involve the use of multilateral wells in staged production processes, so that alternative segments of wells may be used in alternative ways during a recovery process, for example repurposing sections of an injection well as a production well at a stage in a recovery process when there is surplus injection well infrastructure in place.

Abstract: A method for performing shale gas operation is disclosed. The method may include drilling a first well, performing a fracturing operation in the well, recovering shale gas from the first well, supplying at least part of the shale gas recovered from the well to an electrical generator, generating electricity using the generator, and transferring the generated electricity to drilling equipment used to drill a second well.

Abstract: A method and system for use in association with a subterranean reservoir containing reservoir material, for separating the reservoir material into components and for producing one or more of the reservoir material components at a surface production location. The reservoir material components include one or more liquid components and a solid component. The system includes a subterranean cavern located below the reservoir. A drain extends between the reservoir and the cavern for draining the reservoir material from the reservoir into the cavern so that the reservoir material may be collected and separated into the reservoir material components in the cavern. A production well extends between the cavern and the surface production location for producing one or more of the reservoir material components at the surface production location. Preferably, one or more of the liquid components are produced at the surface production location while retaining the solid component in the cavern.

Abstract: A method and apparatus for producing hydrocarbons from a subterranean formation. A first well is provided in the formation, the first well being separated by an isolating material into at least a first and second zone, the first zone being substantially isolated from the second zone. A second well is provided in the formation. The second well is separated by an isolating material into at least a first and second zone, the first zone being substantially isolated from the second zone. A first fracture is provided in the formation, the first fracture extending substantially between the first zones. A second fracture is provided in the formation, the second fracture extending substantially between the second zones of the first and second wells. A fluid is injected into the formation from the first zone in the first well. Hydrocarbons are produced at the second zone of the second well.

Abstract: Methods and systems are provided for selectively displacing water from a hydraulically continuous water zone in a porous geological formation. The target zone to be displaced is defined by a hydrodynamically maintained pressure differential, which has been shown to be capable of confining an expanding injected gas zone. One or more gas injection wells and water production wells are located within the zone. During pressurized gas injection within the zone, the gas displaces water downward within the confined zone such that water is selectively produced from the target zone and the injected gas zone is confined within the hydraulically continuous water zone.

Abstract: A method for determining along relatively uniformly spaced apart parallel first and second wellbores situated in an underground hydrocarbon-containing formation, regions within the formation, including in particular regions between such wellbores, where injection of a fluid at a pressure above formation dilation pressure may be advantageous in stimulating production of oil into the second of the two wellbores, and subsequently injecting fluid at pressures above formation dilation pressures at the discrete regions along such wellbores determined to be in need. An initial information-gathering procedure is conducted, wherein fluid is supplied under a pressure less than formation dilation or fracture pressure, to discrete intervals along a first wellbore, and sensors in the second wellbore measure and data is recorded regarding the ease of penetration of such fluid into the various regions of the formation intermediate the two wellbores.

Abstract: The method begins by forming a gravity drainage production well pair within a formation comprising an injection well and a production well. The pre-soaking stage begins by soaking at least one of the wellbores of the well pair with a solvent, wherein the solvent does not include water. The pre-heating stage begins by heating the soaked wellbore of the well pair to produce a vapor. The squeezing stage begins by introducing the vapor into the soaked wellbore of the well pair, and can thus overlap with the pre-heating stage. The gravity drainage production begins after the squeezing stage, once the wells are in thermal communication and the heavy oil can drain to the lower well.

Abstract: The present invention provides grain-drying facilities which can effectively use the heat energy of a biomass combustion hot-air that has been generated in a biomass combustion furnace.

Abstract: A method for producing bitumen or heavy oil from a reservoir, the method comprising: defining at least one lateral section of the reservoir for placement of patterns of heater wells above a producer well; placing the producer well at a substantially centered location at or adjacent to the bottom of the reservoir within each of the lateral sections; placing a triangular pattern of heater wells above the producer well; placing a regular or non-regular pentagonal pattern of heater wells, or a portion thereof, at or above the triangular pattern of heater wells; heating the reservoir with the triangular and pentagonal patterns of heater wells to conductively heat the reservoir and reduce the viscosity of the bitumen or heavy oil; and producing bitumen or heavy oil with the producer well.

Abstract: A method is taught of creating one or more targeted fractures in a subterranean formation. The method comprises the steps of drilling and completing two wells in the formation, conditioning said wells to create a stress condition favorable for forming a fracture zone connecting said two wells and initiating and propagating the fracture zone in said formation.

Abstract: A system for heating hydrocarbon resources in a subterranean formation having spaced-apart wellbores therein aligned in a plane may include radio frequency (RF) antennas to be positioned within respective ones of the spaced apart wellbores aligned in the plane. The system may also include a plurality of discrete RF sources each coupled to one of the RF antennas and configured so that the RF antennas are driven at a same frequency as each other RF antenna but at different phases.

Abstract: A method of gas production from a field containing natural gas processing particularly for transport of stranded gas to conserve resources and reduce emissions includes extracting gas a gas supply from a plurality of individual gas wells in the field and initially at the individual gas wells providing a recovery unit having a production capacity matching that of the well for carrying out liquid recovery from the gas supply and compression of the natural gas. When a production rate of the well declines to a low level, typically to about 20% of the original, the recovery unit is removed for redeployment either at a central plant or at other wells which are still at the high production and is substituted by a dehydration system and gas compressor arranged to fill portable pressure vessels typically on trucks for transporting the compressed natural gas to a main pipe line.

Abstract: Systems and methods for decreasing compaction within a pyrolyzed zone are disclosed herein. The methods include injecting a sealing fluid into the pyrolyzed zone and flowing the sealing fluid to a peripheral region of the pyrolyzed zone. The methods further include fluidly sealing the peripheral region of the pyrolyzed zone with a sealing fluid where fluidly sealing limits a fluid leakage from the pyrolyzed zone. Subsequent to the fluidly sealing, the methods further include pressurizing the pyrolyzed zone to a zone pressure. The systems include hydrocarbon production systems and/or components thereof that are formed using the methods.

Abstract: Downhole tools and techniques acquire information regarding nearby conductors such as pipes, well casing, and conductive formations. At least some method embodiments provide a current flow along a drill string in a borehole. The current flow disperses into the surrounding formation and causes a secondary current flow in the nearby conductor. The magnetic field from the secondary current flow can be detected using one or more azimuthally-sensitive antennas. Direction and distance estimates may be obtainable from the azimuthally-sensitive measurements, and can be used as the basis for steering the drillstring relative to the distant conductor. Possible techniques for providing current flow in the drillstring include imposing a voltage across an insulated gap or using a toroid around the drillstring to induce the current flow.

Abstract: A method for performing shale gas operation is disclosed. The method may include drilling a first well, performing a fracturing operation in the well, recovering shale gas from the first well, supplying at least part of the shale gas recovered from the well to an electrical generator, generating electricity using the generator, and transferring the generated electricity to drilling equipment used to drill a second well.

Abstract: A method of permeating and infusing a formation around the borehole with wax by heating a formation surrounding a borehole and pumping molten wax into the formation, wherein the molten wax flows into and fills voids the formation without disrupting the formation is described. Also, a method of permeating and infusing a formation around the borehole with wax by heating a formation surrounding a borehole, pumping molten wax into the borehole, heating and circulating the molten wax vertically within the borehole for an extended period using a heater and pump attached to a circulation pipe extended to the bottom of a zone of the borehole to be heated, and recovering molten wax from the borehole by displacing it back to the surface with another material of different density is described.

Abstract: The invention relates to a method of extracting oil from a reservoir. The method comprises the following steps: drilling of a first well; mounting and cementing of well pipes in the first well; mounting of a Blow Out Preventer or Lubricator in the top of the well. At a distance from this well, a second well is drilled against a section of the first well such that the second well gets into operational contact with the first well. Hereafter well pipes are mounted and cemented in the second well; a Blow Out Preventer or Lubricator is mounted in the top of the second well; where after the drilling from the first or the second well is continued down into the reservoir.

Abstract: The present disclosure relates to a particularly effective well configuration that can be used for SAGD and other steam based oil recovery methods. A central wellpad originates injector and/or producer wells, arranged in a radial pattern, and either or both provided with multilateral wells, thus effectively expanding the coverage.

Abstract: An installation for the in-situ extraction of a substance including hydrocarbons from an underground deposit is provided. The conductor and return conductor of the inductor lines are guided essentially vertically in the capping to the bottom of the deposit, at a small maximum lateral distance of 10 m compared to the length of the lines, but especially less than 5 m. Preferably, the inductor lines are guided horizontally in the deposit and are at different distances in certain areas. Furthermore, the electrical conductors and return conductors perpendicularly extending in the capping preferably combine to form a conductor pair. In this way, the conductor pair can be introduced into a single borehole which reaches into the reservoir and splits only once it has arrived in the reservoir.

Abstract: Methods are described for using heated fluids from enhanced geothermal systems projects that recover geothermal heat from hot dry rock resources, and then injecting the heated pressurized fluids into a suitable rock formation to create an artificial geothermal energy reservoir. The artificial geothermal reservoir can then be used to store thermal energy by boosting the enthalpy of injected fluids by exchanging against heated fluids from other sources including a solar thermal power plant. Recovered heated fluids are utilized in a geothermal power plant and the spent geothermal fluids can be injected to recover additional thermal energy from hot dry rock resources. One embodiment is a geosolar electric power generation project to provide a steady and flexible source of renewable energy from a hot dry rock geothermal source integrated with a concentrating solar power project.

Abstract: Techniques for recovering hydrocarbons, such as heavy hydrocarbons or bitumen, from a cellar region below a horizontal production well can include providing a cellar well section that extends from the horizontal production well into the cellar region. The horizontal production well can be part of a Steam-Assisted Gravity Drainage (SAGD) in situ recovery system, which forms a hydrocarbon depleted region and a hydrocarbon bearing cellar region. The cellar region includes hydrocarbons that have been pre-heated by SAGD operations. One or more cellar well sections are provided from the SAGD production well to extend into the cellar region, in order to form a branched production well. A pressurizing gas can be injected into the hydrocarbon depleted region from a SAGD injection well, in order to provide sufficient pressure to promote production of pre-heated hydrocarbons from the cellar region through the cellar well section.

Abstract: According to one embodiment, a system for accessing a subterranean zone from the surface includes a well bore extending from the surface to the subterranean zone, and a well bore pattern connected to the junction and operable to drain fluid from a region of the subterranean zone to the junction.

Abstract: A method for recovering hydrocarbons from a subterranean reservoir by operating a substantially gravity-controlled recovery process with two adjacent well pairs. Each well pair includes an injector well and a producer well. A mobilized zone forms around each well pair through the gravity-controlled recovery process, and a bypassed region forms between the adjacent well pairs when the respective mobilized zone of each well pair merge to form a common mobilized zone. A plurality of infill producer wells are provided in the bypassed region. The plurality of infill producer wells are operated to establish fluid communication between the plurality of infill producer wells and the common mobilized zone. Once fluid communication is established, the plurality of infill producer wells and the adjacent well pairs are operated under a substantially gravity-controlled recovery process, and hydrocarbons are recovered from the plurality of infill producer wells and from the producer wells.

Abstract: Improved SAGD methods for recovering heavy oil from underground formations. In a first aspect a method is provided for drilling, using multi-lateral drilling techniques, a series of horizontal collector wells from a vertical shaft of a production well, below and parallel to an injection well. In a further alternative to the typical SAGD configuration having injector and producer well drilled from the same end of a region under development, the production well is instead drilled at an end of a region of development opposite to an end of such region at which an injector well is drilled. Lastly, in yet another aspect, the invention comprises a method for rejuvenating an existing SAGD well pair, comprising drilling a further production well or wells at an opposite end of said formation at which an existing injector well was drilled, preferably using multi-lateral drilling techniques.

Abstract: Systems and methods for drilling a multilateral well using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a multilateral well includes drilling and casing a mother wellbore, installing a multilateral junction, drilling and casing a first lateral well from the multilateral junction, and drilling a second lateral well from the multilateral junction using magnetic ranging while drilling such that the second lateral well has a controlled relationship relative to the first lateral well. The first and second lateral wells may form a SAGD well pair, in which case the first lateral well may be a producer well and the second lateral well may be an injector well.

Abstract: Methods and systems for performing well network production optimizations are described. For example, in one embodiment, a method of allocating an applied resource throughout a well network includes receiving topological data into an analytical model of a well network having one or more wells. The topological data includes a plurality of performance curves that relate well performance to one or more levels of an applied resource. The method also includes determining an optimum allocation of the applied resource using the analytical model to maximize an operating parameter of the well network, including converting a portion the analytical model having one or more wells and a linear inequality relationship to a modified portion having a single variable and a linear equality constraint.

Abstract: Methods and systems produce petroleum products by steam assisted gravity drainage with dual producers separated vertically and laterally from at least one injector. Placement of the producers limits temperature rise of draining fluids and hence reflux of non-condensable gases injected with steam. In particular, the fluids drain along a steam chamber boundary for recovery at positions that are not in a direct downward path from where the injector is introducing heat.

Abstract: Methods for improving the quality of hydrocarbon fluids produced by in situ pyrolysis or mobilization of organic-rich rock, such as oil shale, coal, or heavy oil. The methods involve reducing the content of olefins, which can lead to precipitation and sludge formation in pipelines and during storage of produced oils. The olefin content is reduced by arranging wells and controlling well pressures such that hydrocarbon fluids generated in situ are caused to pass through and contact pyrolyzed zones in which coke has been left. This contacting chemically hydrogenates a portion of the olefins in the pyrolysis oil by reducing the hydrogen content of the coke.