Liquid carbon dioxide cleaning of wellbores and near-wellbore areas using high precision stimulation
First Claim
1. A method for cleaning a wellbore and near wellbore areas in a coal bed methane formation comprising the steps of:
- inserting a desired length of tubing into said wellbore;
introducing a treatment medium comprising liquid carbon dioxide through said tubing from a jetting tool at the distal end of the tubing and arranged to direct the carbon dioxide into one or more locations within said wellbore and into at least a portion of said formation adjacent to said wellbore;
moving the tubing such that carbon dioxide is introduced to another location within said wellbore and into another portion of the formation adjacent the wellbore and vaporizing at least a portion of said treatment medium after it is injected into said wellbore.
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Accused Products
Abstract
The invention relates to cleaning wellbores and the near wellbore areas adjacent to a hydrocarbon bearing formations and coal bed methane formations. In a particular aspect, the invention relates to removing liquids such as water and/or oil from the formation near the wellbore. The cleaning and liquid removal is accomplished with liquid carbon dioxide or a treatment medium that includes liquid carbon dioxide. The treatment medium is injected into the wellbore through tubing in a controlled manner so that the treatment medium enters the formation in a liquid state, although a portion may be allowed to vaporize upon introduction into the wellbore. The treatment medium is then allowed to vaporize and loosen and entrain undesirable materials from the formation and from within the wellbore or casing, and mobilize water and oil present by effervescing and by dissolving. The water and oil may be blown or pumped to the surface or, if the present invention is practiced in a coal bed methane formation, may be driven into the coal bed methane formation such that it may no longer impose a barrier to methane production. In certain embodiments, the gaseous portion of the treatment medium is allowed to escape through the wellhead, carrying out the undesirable materials.
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Citations
23 Claims
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1. A method for cleaning a wellbore and near wellbore areas in a coal bed methane formation comprising the steps of:
- inserting a desired length of tubing into said wellbore;
introducing a treatment medium comprising liquid carbon dioxide through said tubing from a jetting tool at the distal end of the tubing and arranged to direct the carbon dioxide into one or more locations within said wellbore and into at least a portion of said formation adjacent to said wellbore;
moving the tubing such that carbon dioxide is introduced to another location within said wellbore and into another portion of the formation adjacent the wellbore and vaporizing at least a portion of said treatment medium after it is injected into said wellbore. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- inserting a desired length of tubing into said wellbore;
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14. An apparatus for introducing a treatment medium into a desired space comprising:
- a storage means for storing a quantity of a treatment medium;
a pumping means for delivering said treatment medium to a transport means;
said transport means inserted into said space and operable to transport a quantity of said treatment medium to a location within said desired space; and
means for directing said treatment medium onto a location within said desired space;
wherein said treatment medium is comprised of liquid carbon dioxide and said desired space is defined by at least a portion of a wellbore, a casing within said wellbore, a region of a wellbore located in a coal bed methane formation and/or at least a portion of a coal bed methane formation near said wellbore; and
means for relocating said directing means to a different location in said wellbore wherein the apparatus is configured to introduce the treatment medium to one or more other locations within said wellbore. - View Dependent Claims (15, 16, 17, 18)
- a storage means for storing a quantity of a treatment medium;
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19. A method for removing liquids from a wellbore and the near wellbore areas of a coal bed methane formation comprising the steps of:
- inserting a desired length of tubing into said wellbore;
introducing a treatment medium comprising liquid carbon dioxide through said tubing into one or more locations within said wellbore and into at least a portion of said formation adjacent to said wellbore; and
vaporizing at least a portion of said treatment medium after it is injected into said wellbore. - View Dependent Claims (20, 21, 22, 23)
- inserting a desired length of tubing into said wellbore;
Specification