Open hole straddle system
First Claim
1. A removable packer device for isolating a segment of a well bore comprising:
- (a) a housing for attachment to a tubing string, said housing carrying a pair of axially spaced inflatable packing elements;
(b) a first fluid path through said housing for delivering fluid under pressure from the tubing string to the inflatable packing elements to cause them to expand and sealingly engage with the well bore to isolate the segment of the well bore that lies between the packing elements;
(c) a first valve controlling said first fluid path;
(d) a pressure responsive sensor coupled to actuate said first valve for automatically sealing said inflatable packing elements after the latter have been inflated to a pressure sufficient to ensure their sealing engagement with the well bore, said first valve when so actuated opening a second fluid path from the tubing string to the isolated segment of the well bore; and
(e) an actuator in said housing selectively operable to close said second fluid path and to open a third fluid path through said housing to equalize pressure in the isolated well bore segment with the adjacent regions of the well bore above and below the packing elements, said actuator being coupled for operation in response to a short axial movement of said tubing string.
3 Assignments
0 Petitions
Accused Products
Abstract
A set of inflatable well packing elements are separated by a variable length of tubing and are set in a well to isolate a segment of the annulus by applying fluid under pressure through a tubing string to the well packing elements. The flow of the fluid under pressure to the inflatable packing elements is regulated by a flow control valve which automatically cuts off the fluid flow at a predetermined tubing to annulus pressure differential and opens communication between the tubing string and the isolated well zone. Fluid may thereafter be pumped into or swabbed from the isolated zone. Upon completing the zone servicing, pulling the tubing string up slightly will both equalize the pressure across the inflatable packing elements, and deflate the packing elements. Thereafter, the tubing string may be retrieved from the well or, if desired, moved to another location which can be serviced in the same manner.
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Citations
13 Claims
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1. A removable packer device for isolating a segment of a well bore comprising:
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(a) a housing for attachment to a tubing string, said housing carrying a pair of axially spaced inflatable packing elements; (b) a first fluid path through said housing for delivering fluid under pressure from the tubing string to the inflatable packing elements to cause them to expand and sealingly engage with the well bore to isolate the segment of the well bore that lies between the packing elements; (c) a first valve controlling said first fluid path; (d) a pressure responsive sensor coupled to actuate said first valve for automatically sealing said inflatable packing elements after the latter have been inflated to a pressure sufficient to ensure their sealing engagement with the well bore, said first valve when so actuated opening a second fluid path from the tubing string to the isolated segment of the well bore; and (e) an actuator in said housing selectively operable to close said second fluid path and to open a third fluid path through said housing to equalize pressure in the isolated well bore segment with the adjacent regions of the well bore above and below the packing elements, said actuator being coupled for operation in response to a short axial movement of said tubing string. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of setting a pair of axially spaced well packers in a well bore for isolating therebetween a segment of such well bore, comprising:
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(a) running the pair of packers on a tubing string to a selected position in the well bore; (b) inflating packing elements of said packers into sealing engagement with the well bore by supplying fluid under pressure thereto through the tubing string; (c) setting said packers by automatically locking the packing elements in sealed inflated condition in response to a preset pressure condition being reached, such that said packing elements remain locked in sealing engagement with said well bore irrespective of subsequent changes in pressure conditions in said well bore and in said tubing string; and (d) thereafter automatically opening a fluid path from the tubing string to the segment of the well bore isolated between the packing elements. - View Dependent Claims (10, 11)
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12. A method for setting, removing and resetting a pair of axially spaced packers for isolating a segment of well bore therebetween, comprising:
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(a) running the pair of packers on a tubing string to a selected position in the well bore; (b) inflating packing elements of said packers into sealing engagement with the well bore by supplying fluid under pressure thereto through the tubing string; (c) setting the packers by automatically sealing the packing elements in inflated condition in response to a preset pressure condition being reached; (d) automatically opening a path from the tubing string to the segment of well bore isolated between the packing elements; (e) for removal of the packers, subsequently equalizing the pressure across the packing elements by opening a fluid path between the isolated bore segment and an adjacent region of the bore beyond the packing elements; (f) automatically deflating the packing elements by releasing pressurized fluid contained therein; and (g) resetting the packers by repeating steps (a) to (d) above. - View Dependent Claims (13)
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Specification