SYSTEMS AND METHODS FOR INITIATING ANNULAR OBSTRUCTION IN A SUBSURFACE WELL
First Claim
1. A system for initiating annular obstruction in a subsurface well, said system comprising:
- a) an at least partially permeable liner string situated within a portion of a wellbore that is at least partially open to a hydrocarbon-bearing formation;
b) a load-bearing coiled spring disposed about a portion of the at least partially permeable liner string, wherein the load-bearing coiled spring is in a load-bearing state selected from the group consisting of a tensioned state and a compressed state;
c) a spring retainer device attached to the load-bearing coiled spring so as to maintain it in a load-bearing state, wherein the spring retainer device is at least partially fabricated of material designed to melt above a predetermined temperature, and wherein upon melting loses its ability to maintain the coiled spring in a load-bearing state; and
d) metal mesh interposed with the load-bearing spring such that removal of the load from the spring causes the metal mesh to engage the formation, thereby forming an annular obstruction between the liner string and the formation, wherein the load removal is effected by application of heat to the annular region sufficient to melt at least a portion of the spring retainer device.
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Accused Products
Abstract
The present invention is directed to systems and methods for initiating annular obstructions in wells used in, or in support of, enhanced oil recovery operations—particularly enhanced oil recovery (EOR) efforts involving steam injection (e.g., steam flooding). In at least some instances, system and method embodiments of the present invention utilize one or more passively-activated annular obstruction devices (and/or hybrid active/passive devices) for inducing annular obstruction, wherein the associated passive or hybrid activation is at least partially controlled by thermal means such that it can be deemed to be thermally-directed or thermally-controlled. Such thermally-directed passive activation can afford considerably more control over the annular obstruction process and, correspondingly, over the overall steam injection into the formation and associated reservoir—thereby providing more efficient recovery of hydrocarbons.
16 Citations
25 Claims
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1. A system for initiating annular obstruction in a subsurface well, said system comprising:
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a) an at least partially permeable liner string situated within a portion of a wellbore that is at least partially open to a hydrocarbon-bearing formation; b) a load-bearing coiled spring disposed about a portion of the at least partially permeable liner string, wherein the load-bearing coiled spring is in a load-bearing state selected from the group consisting of a tensioned state and a compressed state; c) a spring retainer device attached to the load-bearing coiled spring so as to maintain it in a load-bearing state, wherein the spring retainer device is at least partially fabricated of material designed to melt above a predetermined temperature, and wherein upon melting loses its ability to maintain the coiled spring in a load-bearing state; and d) metal mesh interposed with the load-bearing spring such that removal of the load from the spring causes the metal mesh to engage the formation, thereby forming an annular obstruction between the liner string and the formation, wherein the load removal is effected by application of heat to the annular region sufficient to melt at least a portion of the spring retainer device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for initiating annular obstruction in a subsurface well, said method comprising:
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a) fabricating an at least partially permeable length of modified liner string, the length of modified liner string comprising; i) a load-bearing coiled spring disposed about at least a portion of the modified liner string, wherein the load-bearing coiled spring is in a load-bearing state selected from the group consisting of a tensioned state and a compressed state; ii) a spring retainer device attached to the load-bearing coiled spring so as to maintain it in the load-bearing state, wherein the spring retainer device is at least partially fabricated of material designed to melt above a predetermined temperature, and wherein upon melting loses its ability to maintain the coiled spring in a load-bearing state; and iii) metal mesh interposed with the load-bearing coiled spring such that when the coiled spring undergoes a transformation from a load-bearing state to a non-load-bearing state, the metal mesh expands outward in a radial direction; b) positioning the modified length of modified liner string in an open hole region of a wellbore, wherein an annular region is established between the modified length of liner string and the open hole region of the wellbore; and c) heating the modified length of liner string so as to melt the spring retainer device and effect the transformation of the coiled spring to the non-load-bearing state, correspondingly causing the metal mesh to expand outwardly and engage the formation, thereby forming an annular obstruction between the modified length of liner string and the open hole. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification