Provided is a downhole fracturing tool assembly, a well system, and a method for fracturing a well system. The downhole fracturing tool assembly, in one aspect, includes a fracturing port cover coupleable to an interior of a wellbore casing having one or more fracturing ports therein. The downhole fracturing tool assembly, according to this aspect, further includes a fracturing port cover actuator coupled to the fracturing port cover, the fracturing port cover actuator operable to move the fracturing port cover between a first position sealing the one or more fracturing ports from an interior of the wellbore casing and a second position exposing the one or more fracturing ports to the interior of the wellbore casing, and fracturing port cover electronics coupled to the fracturing port cover actuator proximate the fracturing port cover, the fracturing port cover electronics operable to activate the fracturing port cover actuator.

Provided is a downhole fracturing tool assembly, a well system, and a method for fracturing a well system. The downhole fracturing tool assembly, in one aspect, includes a fracturing port cover coupleable to an interior of a wellbore casing having one or more fracturing ports therein. The downhole fracturing tool assembly, according to this aspect, further includes a fracturing port cover actuator coupled to the fracturing port cover, the fracturing port cover actuator operable to move the fracturing port cover between a first position sealing the one or more fracturing ports from an interior of the wellbore casing and a second position exposing the one or more fracturing ports to the interior of the wellbore casing, and fracturing port cover electronics coupled to the fracturing port cover actuator proximate the fracturing port cover, the fracturing port cover electronics operable to activate the fracturing port cover actuator.

A method includes disposing a device into a borehole in proximity to a subterranean formation where a filter cake has been formed adjacent thereto, the device comprising a support structure and a shape-memory article disposed at the support structure, the shape-memory article comprising a shape-memory polymer, wherein the device is disposed when the shape-memory article is in a compacted shape; exposing the shape-memory article to a fluid system to cause the shape-memory article to expand and conform to a surface of the borehole; exposing the filter cake to the fluid system; and removing the filter cake with the fluid system. The fluid system comprises (i) an acid component, a chelating agent, or a combination thereof; (ii) an activator, (iii) a viscosifier, (iv) water or a brine, and (v) optionally a surfactant.

An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured tool body assembly having valving members (e.g., safety or kelly values) and valving members holding plugs, balls, or darts to be dropped. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation. An optional indicator indicates to a user or operator that a ball or plug has passed a selected one of the valving members. A transmitter (or transceiver) provides an ability to generate a wireless signal that is received by receivers (or transceivers) on the tool body assembly. Each receiver (or transceiver) controls an electrical actuator that engages a valving member or the indicator. Wireless signals can be used to open or close a valve or to reset a “tripped” indicator.

An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured tool body assembly having valving members (e.g., safety or kelly values) and valving members holding plugs, balls, or darts to be dropped. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation. An optional indicator indicates to a user or operator that a ball or plug has passed a selected one of the valving members. A transmitter (or transceiver) provides an ability to generate a wireless signal that is received by receivers (or transceivers) on the tool body assembly. Each receiver (or transceiver) controls an electrical actuator that engages a valving member or the indicator. Wireless signals can be used to open or close a valve or to reset a “tripped” indicator.

A liner string includes a liner hanger assembly and a liner hanger deployment assembly. The liner hanger assembly includes a liner hanger. The liner hanger includes a plurality of slips and a liner hanger actuation assembly configured to set the plurality of slips. The liner hanger deployment assembly is disposed within the liner hanger assembly. The liner hanger deployment assembly includes a setting tool configured to selectively allow fluid communication between a central bore of the setting tool and the liner hanger actuation assembly.

Some embodiments of the inventive subject matter improve techniques for measuring downhole attributes. A method for determining a flow rate of a fluid includes positioning a tubular within a wellbore formed in a subsurface formation, wherein a flow of fluid is to move through the tubular. An orifice plate is positioned in the tubular. The orifice plate is movable between a first position and a second position to alter a flow area of the flow of fluid moving through the tubular. The method includes detecting a change in a downhole attribute that changes in response to the alteration of the flow area of the flow of fluid. Sensors positioned within or in communication with an interior of the tubular can detect the change in the downhole attribute. The method further includes determining a flow rate of the flow of fluid based on the detected change in the downhole attribute.

Some embodiments of the inventive subject matter improve techniques for measuring downhole attributes. A method for determining a flow rate of a fluid includes positioning a tubular within a wellbore formed in a subsurface formation, wherein a flow of fluid is to move through the tubular. An orifice plate is positioned in the tubular. The orifice plate is movable between a first position and a second position to alter a flow area of the flow of fluid moving through the tubular. The method includes detecting a change in a downhole attribute that changes in response to the alteration of the flow area of the flow of fluid. Sensors positioned within or in communication with an interior of the tubular can detect the change in the downhole attribute. The method further includes determining a flow rate of the flow of fluid based on the detected change in the downhole attribute.

A method for reducing water production from a hydrocarbon bearing subterranean formation includes identifying a high permeability zone in the formation and injecting a dense CO.sub.2 composition from a production well into the high permeability zone. The dense CO.sub.2 composition includes dense CO.sub.2 and a thickener soluble in the dense CO.sub.2. The thickener includes a copolymer that is the polymerized reaction product of monomers that include at least one alkenyl ether or dialkenyl ether monomer, at least one acrylate or methacrylate monomer, at least one structural monomer, and at least one allyl ester monomer. After injecting the dense CO.sub.2 composition into the high permeability zone, the method includes withdrawing hydrocarbons from the hydrocarbon bearing subterranean formation through the production well. The dense CO.sub.2 composition blocks pores in the high permeability zone to reduce or prevent flow of water from the high permeability zone into the production well.

A method for reducing water production from a hydrocarbon bearing subterranean formation includes identifying a high permeability zone in the formation and injecting a dense CO.sub.2 composition from a production well into the high permeability zone. The dense CO.sub.2 composition includes dense CO.sub.2 and a thickener soluble in the dense CO.sub.2. The thickener includes a copolymer that is the polymerized reaction product of monomers that include at least one alkenyl ether or dialkenyl ether monomer, at least one acrylate or methacrylate monomer, at least one structural monomer, and at least one allyl ester monomer. After injecting the dense CO.sub.2 composition into the high permeability zone, the method includes withdrawing hydrocarbons from the hydrocarbon bearing subterranean formation through the production well. The dense CO.sub.2 composition blocks pores in the high permeability zone to reduce or prevent flow of water from the high permeability zone into the production well.