METHOD FOR IMPROVING ISOLATION OF FLOW TO COMPLETED PERFORATED INTERVALS
First Claim
1. A method of building a plug in a horizontal wellbore which penetrates a subterranean formation, the method comprising:
- (a) pumping a fluid pill into the wellbore wherein the fluid pill comprises a suspended well treatment composite, the well treatment composite comprising a core having a dissolvable diverter and a deformable particulate, a viscosifying agent and a crosslinking agent, wherein the viscosifying agent and crosslinking agent are coated onto the core;
(b) disassociating at least a portion of the dissolvable diverter from the core of the well treatment composite and rendering a modified fluid pill comprising the deformable particulate and viscosifying polymer and crosslinking agent coated onto the deformable particulate;
(c) blocking at least a portion of a high permeability zone of a subterranean formation with the disassociated dissolvable diverter;
(d) diverting the flow of the modified fluid pill from a high permeability zone to a lower permeability zone of a subterranean formation;
(e) allowing at least one fracture in the lower permeability zone of the subterranean formation to partially close;
(f) at least partially preventing the deformable particulate from entering the at least one fracture by forming a thickened gel containing the deformable particulate, wherein the thickened gel is formed by the in-situ reaction of;
(i) the crosslinking agent disassociated from the core; and
(ii) viscosifying polymer disassociated from the core; and
(g) forming a fluid-impermeable plug with the thickened gel containing the deformable particulate.
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Accused Products
Abstract
A method for building a plug in a horizontal wellbore using a fluid pill containing a suspended well treatment composite. The well treatment composite contains a core comprising at least one deformable particulate and at least one dissolvable diverter. At least a portion of the surface of the core is coated with at least one viscosifying polymer and at least one crosslinking agent. The fluid pill is pumped into the wellbore at the end of a fracturing treatment and the fluid pill may be displaced by a displacement fluid. The fluid pill may be diverted to an area of lower permeability by disassociating the dissolvable diverter from the core. The disassociated diverter blocks an area of higher permeability. The sized particle distribution of the diverter is sufficient to at least partially block the penetration of fluid into the high permeability zone. In the lower permeability zone, a thickened gel is formed by the in-situ reaction of the viscosifying polymer and crosslinking. Deformable particulates in the gelled fluid form a bridge plug.
34 Citations
25 Claims
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1. A method of building a plug in a horizontal wellbore which penetrates a subterranean formation, the method comprising:
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(a) pumping a fluid pill into the wellbore wherein the fluid pill comprises a suspended well treatment composite, the well treatment composite comprising a core having a dissolvable diverter and a deformable particulate, a viscosifying agent and a crosslinking agent, wherein the viscosifying agent and crosslinking agent are coated onto the core; (b) disassociating at least a portion of the dissolvable diverter from the core of the well treatment composite and rendering a modified fluid pill comprising the deformable particulate and viscosifying polymer and crosslinking agent coated onto the deformable particulate; (c) blocking at least a portion of a high permeability zone of a subterranean formation with the disassociated dissolvable diverter; (d) diverting the flow of the modified fluid pill from a high permeability zone to a lower permeability zone of a subterranean formation; (e) allowing at least one fracture in the lower permeability zone of the subterranean formation to partially close; (f) at least partially preventing the deformable particulate from entering the at least one fracture by forming a thickened gel containing the deformable particulate, wherein the thickened gel is formed by the in-situ reaction of; (i) the crosslinking agent disassociated from the core; and (ii) viscosifying polymer disassociated from the core; and (g) forming a fluid-impermeable plug with the thickened gel containing the deformable particulate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of building a plug in a horizontal wellbore, the method comprising:
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(a) pumping a fracturing fluid into the horizontal wellbore at a pressure sufficient to create or enlarge a fracture in the subterranean formation penetrated by the wellbore; (b) pumping into the wellbore a fluid pill having a well treatment composite suspended therein, the well treatment composite comprising a solid core comprising a dissolvable diverter and a deformable particulate and a viscosifying polymer and crosslinking agent coated onto the core; (c) pumping a displacement fluid down the wellbore and displacing the fluid pill further into the wellbore in proximity to a perforation tunnel in a desired location; (d) flowing the fluid pill into a high permeability zone, blocking at least a portion of the higher permeability zone with the dissolvable diverter, forming a modified fluid pill and flowing the modified fluid pill into a lower permeability zone of the formation, wherein the modified well treatment composite has a core comprising the deformable particulate and viscosifying polymer and crosslinking agent coated onto the deformable particulate; (e) allowing at least one fracture within the horizontal wellbore to at least partially close, the modified well treatment composite remaining suspended within the modified fluid pill; (f) pumping the displacement fluid down the horizontal wellbore to slowly displace the modified fluid pill; (g) increasing the viscosity of the modified fluid pill to form a gelled fluid by the in-situ reaction of; (i) the crosslinking agent as it is disassociated from the deformable core; and (ii) viscosifying polymer disassociated from the deformable core; and (h) at least partially preventing the gelled fluid containing the deformable particulate from entering the at least one fracture in the zone, wherein the gelled fluid forms a fluid-impermeable plug within the wellbore. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method for building a plug in a horizontal wellbore comprising:
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(a) suspending a well treatment composite within a fluid, the well treatment composite comprising a core of a dissolvable diverter and a deformable particulate and a viscosifying polymer and crosslinking agent coated onto the core; (b) diverting the flow of the fluid pill to a low permeability zone of a subterranean formation penetrated by the wellbore; (c) dissolving the dissolvable diverter to provide a modified fluid pill comprising a modified well treatment composite having a core comprising the deformable particulate and viscosifying polymer and crosslinking agent coated onto the deformable particulate; (d) displacing the modified fluid pill; (e) allowing at least one fracture in the low permeability zone of the horizontal wellbore to partially close; (f) continuing to displace the modified fluid pill after the at least one fracture in the zone has partially closed, wherein a gelled fluid containing the deformable core bridges off forming a plug within the wellbore; and further wherein during displacement of the modified fluid pill, the thickened gel is formed by the in-situ reaction of; (i) the crosslinking agent after being disassociated from the deformable particulate; and (ii) viscosifying polymer after being disassociated from the deformable particulate.
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Specification