BACKGROUND

The present disclosure relates generally to wellbore technology. More specifically, the present disclosure relates to downhole tools usable for placing materials in the wellbore.

Wellbores may be drilled to reach subsurface locations. Drilling rigs may be positioned about a wellsite, and a drilling tool advanced into subsurface formations to form the wellbore. During drilling, mud may be passed into the wellbore to line the wellbore and cool the drilling tool. Once the wellbore is drilled, the wellbore may be lined with casing and cement to complete the wellbore. Production equipment may then be positioned at the wellbore to draw subsurface fluids to the surface. Fluids may be pumped into the wellbore to treat the wellbore and to facilitate production.

In some cases, part or all of the wellsite may be plugged and/or sealed. For example, perforations may be drilled in a side of the wellbore to reach reservoirs surrounding the wellbore. Plugs may be inserted into the perforations to seal the wellbore from passage of fluid into the wellbore. Examples of plugs and/or plugging technology are provided in U.S. Pat. Nos. 9,062,543, 6,991,048, and 7,950,468, the entire contents of which are hereby incorporated by reference herein.

In some other cases, cementing tools may be deployed into the wellbore to drop cement into the wellbore to seal portions of the wellbore. Examples of cementing are provided in U.S. Pat. Nos. 5,033,549, 9,080,405, 9,476,272, 2014/0326465, and 2017/0175472, the entire contents of which are hereby incorporated by reference herein. The cement may also be used to seal materials in the wellbore.

Despite the advancements in wellbore technology, there remains a need for devices capable of effectively and efficiently placing materials in the wellbore. The present disclosure is directed at providing such needs.

SUMMARY

In at least one aspect, the disclosure relates to a downhole placement tool for placing a wellbore material in a wellbore. The downhole placement tool comprises an actuation assembly and a placement assembly. The actuation assembly comprises an actuation housing having a fluid pathway therethrough and an actuation piston seated in the actuation housing to block the fluid pathway. The actuation piston is movable by fluid applied thereto to open the fluid pathway and allow the fluid to pass through the fluid pathway. The placement assembly is connected to the actuation assembly, and comprises a placement housing having a pressure chamber to store the wellbore material therein; a door positioned in an outlet of the placement housing; and a placement piston. The placement piston is positioned in the placement housing, and comprises a piston head and a placement rod. The piston head is slidably movable in the placement housing. The placement rod is connected between the piston head and the door. The piston head is movable in response to flow of the fluid from the actuation assembly into the placement assembly to advance the placement piston and open the door whereby the wellbore material is selectively released into the wellbore.

The placement tool may have various features and/or combinations of features as set forth below:

The actuation assembly further comprises one of a ball actuator and an electro-hydraulic actuator. The actuation assembly further comprises a support positioned in the actuation housing and wherein the actuation piston comprises a disc removably seated in an opening in the support. The actuation assembly further comprises a rupture disc positioned in the actuation housing and wherein the actuation piston comprises a piercing rod having a tip extendable through the rupture disc. The downhole placement tool further comprises a deflection plate between the actuation assembly and the placement assembly. The actuation assembly further comprises a filtration or a plug sub. The actuation assembly further comprises a sub with the fluid pathway extending therethrough, and the actuation piston has tabs at a downhole end thereof positionable against the sub to define a fluid gap therebetween. The downhole placement tool further comprises shear pins releasably positioned about the actuation piston, the placement housing, the support, the actuation housing, the door, and/or the placement rod. The downhole placement tool further comprises filters positionable in the fluid pathway.

The downhole placement tool further comprises a crossover sub connecting the actuation assembly to the placement assembly. The placement assembly further comprises a metering sub with channels for passing fluid from the actuation assembly into the pressure chamber. The downhole placement tool further comprises a perforated sleeve with a hole to receive the placement rod therethrough. The placement rod comprises a piston rod and a push rod. The piston rod is connected to the piston head and movable therewith, and the push rod is connected to the door and has a hole to slidingly receive an end of the piston rod. The downhole placement tool further comprises a valve positioned about the push rod to selectively permit fluid to pass into the push rod. The downhole placement tool further comprises a disc supported in the pressure chamber, the placement rod extending through the disc. The downhole placement tool further comprises a peripheral screen slidingly positionable in the placement housing. The peripheral screen comprises a plate with a hole to receive the placement rod therethrough and a tubular screen, the tubular screen extending from the plate. The wellbore material comprises bentonite. The pressure chamber is shaped to receive the wellbore material having a spherical shape, a disc shape, a box shape, a fluted shape, a cylindrical shape, and/or combinations thereof. The wellbore material has a cylindrical body with peripheral cuts extending from a periphery towards a center thereof, the cuts shaped to permit passage of the fluid therein.

In another aspect, the disclosure relates to a method of placing a wellbore material in a wellbore. The method comprises placing a wellbore material in a pressure chamber of a placement tool; deploying the placement tool into the wellbore; and releasing the wellbore material into the wellbore by: pumping fluid from a surface location into the placement tool to unblock a blocked fluid pathway to the pressure chamber; and allowing the fluid to pass from the fluid pathway and into the pressure chamber to increase a pressure in the pressure chamber sufficient to open a door of the pressure chamber.

The method further comprises triggering the fluid to flow from the surface location and into the fluid pathway. The pumping comprises creating an opening in the fluid pathway by unseating a placement piston from a support in the fluid pathway. The pumping comprises creating an opening in the fluid pathway by driving a piercing piston through a rupture disc. The releasing comprises deflecting the fluid as it passes into the pressure chamber. The releasing comprises opening the door by applying pressure from the fluid to a placement piston connected to the door.

Finally, in another aspect, the disclosure relates to a method of placing a wellbore material in a wellbore. The method comprises placing a wellbore material in a pressure chamber of a placement tool; deploying the placement tool into the wellbore; opening a fluid pathway to the pressure chamber by pumping fluid from a surface location and into the deployed placement tool; and releasing the wellbore material into the wellbore by passing the fluid through the fluid pathway and into the pressure chamber until a pressure in the pressure chamber is sufficient to open a door to the pressure chamber.

The method further comprises fluidizing the wellbore material by adding fluid to the pressure chamber after the placing and before the deploying. The method further comprises activating the wellbore fluid by exposing a core of the wellbore material to a wellbore fluid in the wellbore. The activating comprises dropping the wellbore fluid a distance in the wellbore sufficient to wash away a coating of the wellbore material and expose the core to the wellbore material. The deploying comprises deploying the placement tool to a depth a distance above a sealing location, and the method further comprises activating the wellbore material by dropping the wellbore material through the wellbore and allowing wellbore fluid in the wellbore to wash away a coating of the wellbore material as the wellbore material falls through the wellbore.

This summary is not intended to be limiting of the subject matter herein.

