Abstract: A downhole system for multistage fracturing wherein a stopper assembly is installed in a plugging device in manner that allows pressure integrity from above the plugging device, and the stopper assembly is further configured to allow a bore of the plugging device to open with an at least minimal pressure from therebelow in order to remove a stopper from a baffle in order to open a flow path through the plugging device in either direction.

Abstract: A downhole system for multistage fracturing having a first cluster of valves, and a second cluster of valves downhole from the first cluster. Each of the first and second cluster of valves has a frac valve. At least one of the first and the second cluster of valves has a flex valve. A single plugging device is used to open all of the valves in the second cluster, but leaves all valves in the first cluster closed.

Abstract: A system for stimulating a subterranean formation that has a wellbore formed within the subterranean formation; and a tubular disposed within the wellbore. There is a first frac valve disposed within the tubular, the first frac valve having a first sleeve in a closed position, and further configured to move to an open position. There is an at least a second frac valve disposed within the tubular, the second frac valve having a respective sleeve in a respective closed position, and further configured to move to a respective open position. A dart is configured to pass through the first frac valve without moving the first sleeve, and to subsequently engage the second frac valve to move the respective sleeve to the respective open position.

Abstract: A downhole sleeve tool is provided that includes a lower sub defining a bore and one or more sleeve ports therethrough. There is a piston valve movably positionable within the lower sub to selectively block communication between the bore and the one or more sleeve ports. There is an upper sub connectable to the lower sub and sharing another bore therewith. The upper sub has an inlet port, one or more communication ports, and an outlet port. There is an at least one cartridge assembly disposed in a cartridge bore formed in a wall of the upper sub.

Abstract: A system is provided, run on a liner, for stimulating one or more stages of a downhole wellbore. The system includes one or more frac valves arranged on the liner; each of the frac valves presenting an identical inside profile, the frac valves being openable for providing fluid communication between in inside of the liner to outside of the wellbore; and at least one dart deployable into the liner, and being adjustable to pass through one or more frac valves without opening said one or more frac valves, and to engage and open one or more other frac valves. Each of the at least one darts is identical to another. A method is further provided for stimulating one or more stages of a downhole wellbore.

Abstract: A device is provided for positively locating within a profile, wherein the device includes one or more radially resilient locator mechanisms; one or more slips; one or more packing elements; and a stopping mechanism; wherein the one or more locator mechanisms are radially expandable to locate within the profile and wherein the stopping mechanism prevents engagement of the one or more slips and the one or more packing elements unit the one or more locator mechanisms are located in the profile. A method is also provided for applying downhole isolation.

Abstract: A downhole wellbore system is provided, comprising one or more downhole sleeves run on a liner; and an intervention tool deployable into the liner. The intervention tool is reciprocateable within the line and one or more downhole sleeves between any one or more positions selected from the group consisting of: downhole sleeve opening position, downhole sleeve closing position, pull uphole position, push downhole position, and setting in a blank section of the liner position. A method is further provided for manipulating an intervention tool in a liner comprising one or more downhole sleeves. The method comprises the steps of deploying an intervention tool into the liner and reciprocating the intervention tool between one or more positions selected from the group consisting of: downhole sleeve opening position, downhole sleeve closing position, pull uphole position, push downhole position, and setting in a blank section of the liner position.

Abstract: A method is provided for multistage isolation and fluid treatment of a borehole, in which a first frac valve tool and a second frac valve tool are provided, a first packer is mounted downstream from the first frac valve tool, a second packer is mounted between the first frac valve tool and the second frac valve tool, a third packer is mounted upstream from the second frac valve tool, at least one of the first, second and third packers being a hydraulic set packer having a single packing element, the first frac valve tool being moveable between a closed and an open position, the second frac valve tool moveable between a closed and an open position; running the liner into a wellbore; hydraulically setting the single element packers; conveying means for moving the first frac valve tool to the open position; and forcing stimulation fluid out through the first frac sleeve tool.