US 9,810,047 B2Granted

Re-fracturing bottom hole assembly and method

AssigneeBaker Hughes Incorporated

InventorsRuslan V. Filyukov, Bryan J. Tindall, Donald G. Parmer

Life of this patent

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Abstract

A bottom hole assembly to enable reperforation and refracturing a cased hole has a bottom end anchor seal to allow a larger drift dimension in the zones to be perforated and fractured between spaced external seals that preferably set by swelling. A separable section has a seal bore to protect lower pressure rated casing in the upper annulus from overpressure during the refracturing operations. Either existing perforations can be refractured or new perforations made and fractured. With a multiple shot perforating gun all the zones can be perforated and fractured in a single trip with a service string that supports a releasable plug, a gun and frac ports. The BHA can be remove with a line cut above the anchor seal at the bottom and a pull on the tubular sting that takes all the swelling packers out. Location devices can be employed for proper gun placement before firing.

Claims12

Dependent claims

A bottom hole assembly for cased hole recompletion in a borehole extending from a surface to a subterranean location, comprising:

spaced seals mounted externally to a tubular string support and defining at least one perforation and fracturing location there between;
an anchor seal for said tubular string mounted externally to said tubular string further from the surface than said spaced seals such that the drift dimension of said tubular string through said spaced seals is larger than through said anchor seal, said anchor seal selectively supporting said tubular string from the cased hole;
a service string supporting a service string bottom hole assembly further comprising at least one releasable plug below a perforating gun, a perforating gun with at least one shot and at least one fracturing port;
said service string bottom hole assembly when in the tubular string selectively positioned adjacent said at least one perforation and fracturing location for sequential perforation and fracturing with fluid flow through said port at said at least one location.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 14/010,055Filed 26 Aug 2013
Published: US 2015/0053397 A126 Feb 2015
Granted: 7 Nov 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

E21B 43/116
Perforators; Permeators: gun or shaped-charge perforators
E21B 33/124
Packers; Plugs: units with longitudinally-spaced plugs for isolating the intermediate space
E21B 43/26
Methods for stimulating production: by forming crevices or fractures
E21B 33/129
Packers; Plugs: with mechanical slips for hooking into the casing