Methods for downhole sequestration of carbon dioxide
AssigneeSchlumberger Technology Corporation
InventorsTerizhandur S. Ramakrishnan, Romain De Loubens, Yusuf Bilgin Altundas
Life of this patent
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Abstract
Carbon dioxide is sequestered in a formation using a dual completion and injection method that reduces or eliminates upward leak rates of the sequestered carbon dioxide. The dual completion and injection method involves the injection of a benign fluid such as brine (water) into a permeable layer of the formation located above the sequestration layer and which is separated form the sequestration layer by a nearly impermeable layer. The water is preferably injected at the same time the carbon dioxide is injected.
Claims17
A method for sequestration of carbon dioxide in a formation traversed by a cased wellbore, comprising:
- a) finding a location in the formation having a first permeable layer directly overlain by a nearly impermeable layer, which in turn is overlain by a second permeable layer;
- b) completing the wellbore as a dual completion wellbore and with perforations in the casing for the purpose of injecting carbon dioxide into the first permeable layer and injecting water into the second permeable layer;
- and
- c) injecting carbon dioxide and water into their respective layers simultaneously, with the nearly impermeable layer therebetween, where the water is injected at a pressure of at least
- p
- w
-
-
- i
- =
- p
- g
-
-
- i
- -
- ρ
- g
-
- g
-
- (
- z
- 0
- -
- z
- m
-
-
- 0
- )
- +
- ρ
- w
-
- g
-
- (
- z
- 0
- -
- z
- m
-
-
- 2
- )
- -
- C
-
-
- γ
-
- ϕ
- 1
- k
- 1
- ,
- where pwi is the water injection pressure, pgi is the carbon dioxide injection pressure, g is the acceleration due to gravity, ρg and ρw are the densities of the carbon dioxide and water respectively, zm0 is the measurement point for pressure in said first permeable layer, zm2 is the measurement point for pressure in said second permeable layer, z0 is the depth at the top of the first permeable layer, γ is the interfacial tension between said carbon dioxide and said water, φ1 and k1 are the porosity and the permeability of said nearly impermeable layer, and C is a constant.
A method for sequestration of carbon dioxide in a formation traversed by a cased wellbore, comprising:
- a) finding a location in the formation having a first permeable layer directly overlain by a nearly impermeable layer, which in turn is overlain by a second permeable layer;
- b) running simulations of the formation assuming injection of carbon dioxide into the first permeable layer and injection of water along different lengths of the second permeable layer in order to find a length which provides desired results concerning leakage of carbon dioxide from the first permeable layer;
- b) completing the wellbore as a dual completion wellbore and with perforations in the casing along said first permeable layer for the purpose of injecting carbon dioxide into the first permeable layer and with second perforations in the casing along said length which provides desired results for the purpose of injecting water into the second permeable layer;
- and
- c) injecting carbon dioxide and water into their respective layers simultaneously, with the nearly impermeable layer therebetween, where the water is injected at a pressure at least equal to the carbon dioxide injection pressure minus an entry capillary pressure of the carbon dioxide into the said nearly impermeable layer, plus a gravitational head correction for the water and carbon dioxide.
A system for sequestration of carbon dioxide in a formation having a surface and thereunder a first permeable layer directly overlain by a nearly impermeable layer, which in turn is overlain by a second permeable layer, the formation being traversed by a cased wellbore, comprising:
- a) a first pump coupled to a source of carbon dioxide;
- b) a second pump coupled to a source of water;
- c) a dual completion of the cased wellbore, said dual completion coupled to said first pump and to said second pump and providing independent communication between the surface and the first permeable layer and between the surface and the second permeable layer, wherein said first pump pumps the carbon dioxide down the dual completion and into the first permeable layer at a first injection pressure, and simultaneously the second pump pumps the water down the dual completion and into the second permeable layer at a second injection pressure, said second injection pressure at least equal to said first injection pressure plus a gravitational head correction for the water and carbon dioxide minus an entry capillary pressure of the carbon dioxide into the nearly impermeable layer.
Dependencies are inferred from the claim text.