Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
  • E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
  • E21B43/2401—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection by means of electricity
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
  • E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection

Definitions

• SAGD steam assisted gravity drainage
• the heating element can be any type known in the art, including the following: 1) a continuous tube having an electric heating element or 2) a continuous tube permitting circulation of a heated fluid such as steam, gas, superheated liquid, molten salts, or other heated fluids known in the art. These heating elements are typically utilized to preheat the underground formation prior to injection of the steam into the formation.
• the solvent assisted technique includes the following steps: 1 ) the solvent is injected into the formation; 2) the solvent is mixed with the bitumen; 3) the solvent/bitumen mixture is recovered from the bitumen formation; and 4) the solvent is separated from the bitumen, recycled and then used in the formation again.
• US 201 1/0303423 teaches recovering in situ viscous oil from an underground reservoir. Electricity is conducted through the underground reservoir by at least two electrodes in an amount that would, in the absence of solvent injection, cause water in the reservoir to vaporize adjacent to the electrodes. Solvent is injected into the reservoir to mitigate water vaporization adjacent to the electrodes by vaporizing solvent in this region. Oil and solvent are produced through one or more production wells.
• the method disclosed in US 201 1/0303423 does not contemplate an energy efficient process that reduces both solvent usage and water treatment procedures.
• the known enhanced oil recovery technologies are heavily investigated, but still require improvements at every stage.
• the required improvements include 1) simplifying oil recovery the process; 2) reducing the need for materials such as steam and solvents thereby reducing energy consumption for steam generation; 3) reducing water treatment procedures; and 4) improving the process solvent recovery from the bitumen mixture.
• Disclosed herein is a process for recovering hydrocarbons such as bitumen from an underground formation which is designed to increase energy efficiency by reducing 1) surface water treatment and 2) solvent usage.
• bitumen recovery process comprises the following steps:
• the heating element utilizes electricity, steam, or a hot fluid circulating through the well. In a further embodiment, the heating element utilizes electricity, steam, or a hot fluid circulating through the well in a tube. In yet another embodiment, the electricity, steam, or hot fluid is reheated at the surface or in the bore of the well.
• the solvent used in the process comprises propane, butane (normal, iso & mixed), pentane (normal, iso & mixed), or hexane (normal, iso & mixed).
• the solvent is a mixed solvent with a composition from C3 to C8.
• the solvent is a mixed solvent with a composition from C5 to C7. Even further, the solvent composition is a heavier C7 in the initial recovery process and is progressively replaced with lighter hydrocarbons as the process continues.
• steam is injected into the well along with the solvent.
• the produced fluids recovered from the well are primarily bitumen or heavy oil with a small amount of miscible contained solvent and some connate water.
• Figure 1 is a cross-sectional view of single well heating.
• Figure 2 is a cross-sectional view of the end of pre-heating the single well.
• Figure 3 is an alternative view of the end of pre-heating the single well.
• Figure 4 is a cross-sectional view of the single well near abandonment.
• Figure 5 is a production profile of single well heating.
• Figure 6 is a graph showing the production profile of single well heating.
• Figure 7 is a cross-sectional view of solvent recovery in single well heating.
• a well is drilled into the target formation.
• the entire operation may be achieved in a vertical well, slant well, horizontal well or an irregular well having a combination of vertical, horizontal and tilted portions to adapt to the geometry of the formation. Even further, the horizontal well can be extended from the vertical well.
• a single well is used to achieve a gravity driven bitumen or heavy oil production process. However, multiple wells may be heated and produced simultaneously or sequentially, each with their own heat string.
• the well is cased to the bottom of an intermediate casing, where the horizontal section includes a thermal casing and thermal cement. In the horizontal section, the well has a liner with either slotting or screens to control any sand influx.
• a string of tubing 2 is placed into the hole down through the vertical section and out into the horizontal section to a desired length. Then, the tubing 2 subsequently curls back to return along the horizontal run and back to the surface 4.
• the tubing 2 can be fully insulated, partially insulated, or non-insulated.
• the tubing 2 contains a heating medium 6 which could be electricity, steam, or another fluid with high-heat transfer characteristics.
• a heating medium 6 which could be electricity, steam, or another fluid with high-heat transfer characteristics.
• the electricity, steam, or fluid is reheated to the target temperature and then returned to the portion of tubing string 2 in the well.
• the electricity, steam, or fluid is at super-heated or saturated steam condition as it enters the well bore so that it transfers heat to the horizontal section.
• This initial preheating of the formation creates and initiates a depletion chamber. Condensing may take place and, because of the phase change and fixed volume, a thermo-siphon effect will be created.
• a solvent is introduced into the well. Preferably, in the horizontal section of the well, the solvent is added through an additional tubing string.
• the solvent is a straight chain hydrocarbon which is easily vaporized at the well temperature and is miscible with the reservoir bitumen/oil. More preferably, the solvent is a light hydrocarbon such as butane, iso-butane, pentane, hexane or a mixed solvent with similar commercial diluents with a composition from C3 to C8, but the bulk of the solvent volume in the
• an initial fill of solvent in the horizontal well bore should be sufficient to maintain the process.
• the liquid solvent reaches the tube heated by steam, the heat of condensation is released to the solvent.
• the solvent quickly heats to its boiling point and vaporizes. Since vapor is lighter and has a lower density than the liquid phase, solvent vapor will rise in the well bore filling the depletion chamber. The vapor will rise until it reaches a surface that is cool enough to condense it. Generally, the cooling surface will be the bitumen above the cased well. Once the vapor is condensed onto or with the bitumen, a hydrocarbon mixture is created and the viscosity and density of the mixture are much lower than bitumen alone but higher than pure solvent.
• the hydrocarbon mixture will flow by gravity down to the horizontal section of the well, creating a void space above in the reservoir.
• the lighter hydrocarbon mixture falls into the horizontal section of the well bore and meets with the heat of the steam tubing again. This causes the solvent portion of the mixture to evaporate and rise into the void space in a new cycle.
• the bitumen in the well bore is maintained at a warm temperature, which keeps it mobile.
• the mobile bitumen can be recovered from the horizontal well by means known in the art.
• a gas lift or electric submersible pump system 12 can be used to lift the hot bitumen to surface.
• the heat source is positioned at ground level.
• it may be also positioned down hole, as when using a standard ESP (electric submersible pump) which generates a significant amount of heat in the pumping action.
• an electric heating source can be used alone or in combination with other heating sources.
• the solvent will stay in the reservoir throughout the process without the need to top up the solvent. This results in little or no solvent in the production fluid because the solvent remains a working fluid within the reservoir.
• the solvent has a repeating cycle consisting of being warm liquid in the horizontal section to hot vapor rising through the reservoir to a bitumen/solvent mixture flow back to the horizontal section. Because the solvent remains a working fluid in the reservoir, there is no solvent recovery until the end of the process resulting in less solvent used in the overall process.
• bitumen produced from this process will still contain some water, since there is connate water entrapped around the sand grains in the reservoir along with the bitumen. However, the volume of water in the well will be substantially lower. In fact, the 300% volume of water in the bitumen volume experienced in typical SAGD operation is reduced to 15-30% volume of water in the bitumen volume.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
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• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Working-Up Tar And Pitch (AREA)

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• 2013
  • 2013-08-21 WO PCT/CA2013/000730 patent/WO2014029009A1/fr not_active Ceased
  • 2013-08-21 AU AU2013305433A patent/AU2013305433A1/en not_active Abandoned
  • 2013-08-21 EP EP13831655.9A patent/EP2888439A1/fr not_active Withdrawn
  • 2013-08-21 CN CN201380041458.5A patent/CN104520529A/zh active Pending
  • 2013-08-21 RU RU2015101920A patent/RU2015101920A/ru not_active Application Discontinuation
  • 2013-08-21 CA CA2880092A patent/CA2880092A1/fr not_active Abandoned
  • 2013-08-21 BR BR112015003024A patent/BR112015003024A2/pt not_active Application Discontinuation
  • 2013-08-21 SG SG11201500300QA patent/SG11201500300QA/en unknown
  • 2013-08-21 MX MX2015000934A patent/MX2015000934A/es unknown
  • 2013-08-21 US US13/971,893 patent/US20140054028A1/en not_active Abandoned
  • 2013-08-21 PL PL411369A patent/PL411369A1/pl unknown
• 2015
  • 2015-01-22 CO CO15012615A patent/CO7180210A2/es unknown

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