Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
147 words
A method of placing a plug in an uncollapsed region around a continuous perforate liner in a wellbore; said method comprising the steps of: placing a pair of inflatable packers along a predetermined length of said perforate liner so as to seal against an inner surface of said liner where the plug is to positioned, said packers being spaced apart so as to define both a chamber inside the perforate liner and the uncollapsed region to be plugged outside the liner; pumping a predetermined volume of a thixotropic plugging fluid into the chamber and, via the perforate liner, into the region to be plugged, said plugging fluid being characterized by a gelling time comparable to or shorter than the time taken to displace the fluid into the region and by having a gelling strength after said gelling time sufficient to eliminate gravity-induced flow; and removing said packers.
Claim 2
Independent Claim
147 words
A method of placing a plug in an uncollapsed region around a continuous perforate liner in a wellbore; said method comprising the steps of: placing a pair of inflatable packers along a predetermined length of said perforate liner so as to seal against an inner surface of said liner where the plug is to positioned, said packers being spaced apart so as to define both a chamber inside the perforate liner and the uncollapsed region to be plugged outside the liner; pumping a predetermined volume of a thixotropic plugging fluid into the chamber and, via the perforate liner, into the region to be plugged, said plugging fluid being characterized by a gelling time comparable to or shorter than the time taken to displace the fluid into the region and by having a gelling strength after said gelling time sufficient to eliminate gravity-induced flow; and removing said packers.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1, wherein the volume of the chamber is smaller than the volume to be plugged.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 1, wherein the perforate liner is a slotted liner or a pre-packed screen.
Claim 5
Dependent Claim
37 words
A method as claimed in claim 3, wherein the perforate liner is a slotted liner and the plugging fluid is a cement, or the perforate liner is a pre-packed screen and the plugging fluid is a resin.
Claim 6
Dependent Claim
29 words
A method as claimed in claim 1, in which, prior to pumping in the plugging fluid, a wash fluid is pumped through the chamber and region to be plugged.
Claim 7
Dependent Claim
54 words
A method as claimed in claim 1, in which, after the plugging fluid has been pumped into the region to be plugged, the packers are moved to a location separate from the region to be plugged, and a wash fluid is circulated through the chamber and perforate liner to remove unwanted plugging fluid therefrom.
Claim 8
Dependent Claim
39 words
A method as claimed in claim 1 including the steps of: placing tubing through said inflatable packers; and placing a port in said tubing between said packers for the supply of plugging fluid from said tubing into said chamber.
Claim 9
Independent Claim
149 words
A method of isolating a zone of a well which is lined with a continuous perforate liner along a predetermined length of the well, the method including the steps of: placing plugs on either side of the zone along a predetermined length of the perforate liner, the step of placing plugs on either side of said zone including the steps of: placing a pair of packers inside the perforate liner where one of the plugs is to be positioned, the packers being spaced apart so as to define both a chamber inside the perforate liner and also a region to be plugged outside the perforate liner; pumping a predetermined volume of a plugging fluid into the chamber, and via the perforate liner, into the region to be plugged, the plugging fluid being sufficient to displace substantially all other fluids from the region to be plugged; and removing said packers.
Claim 10
Independent Claim
149 words
A method of isolating a zone of a well which is lined with a continuous perforate liner along a predetermined length of the well, the method including the steps of: placing plugs on either side of the zone along a predetermined length of the perforate liner, the step of placing plugs on either side of said zone including the steps of: placing a pair of packers inside the perforate liner where one of the plugs is to be positioned, the packers being spaced apart so as to define both a chamber inside the perforate liner and also a region to be plugged outside the perforate liner; pumping a predetermined volume of a plugging fluid into the chamber, and via the perforate liner, into the region to be plugged, the plugging fluid being sufficient to displace substantially all other fluids from the region to be plugged; and removing said packers.
Claim 11
Dependent Claim
43 words
A method as claimed in claim 8 wherein the plugging fluid has a gelling time comparable to or shorter than the time taken to displace the fluid into said region and a gelling strength after said gelling time sufficient to eliminate gravity-induced flow.
Claim 12
Dependent Claim
39 words
A method as claimed in claim 9 including the further steps of: placing tubing through said packers and placing a port in said tubing adjacent said packers for the supply of plugging fluid from said tubing into said chamber.