Cementing plugs and methods of forming cementing plugs containing a plurality of objects are disclosed. In some implementations, the cementing plug includes a body having a plurality of objects dispersed within the body. One or more of the objects may protrude from a surface of the body of the cementing plug. In some implementations, the plurality of objects may be irregularly-shaped, uniformly-shaped, or a combination of irregularly-shaped and uniformly-shaped. The plurality of objects may be randomly distributed in the body of the cementing plug or uniformly arranged in the body of the cementing plug. In some implementations, a portion of the plurality of objects may be uniformly arranged and another portion of the plurality of objects may be randomly distributed in the body of the cementing plug.

Cementing plugs and methods of forming cementing plugs containing a plurality of objects are disclosed. In some implementations, the cementing plug includes a body having a plurality of objects dispersed within the body. One or more of the objects may protrude from a surface of the body of the cementing plug. In some implementations, the plurality of objects may be irregularly-shaped, uniformly-shaped, or a combination of irregularly-shaped and uniformly-shaped. The plurality of objects may be randomly distributed in the body of the cementing plug or uniformly arranged in the body of the cementing plug. In some implementations, a portion of the plurality of objects may be uniformly arranged and another portion of the plurality of objects may be randomly distributed in the body of the cementing plug.

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 example system for isolating cement slurry from drilling fluids includes a tool configured for installation on a landing collar of a casing. The tool includes a base that conforms to an inner circumference of the casing and a tube that extends uphole from the base. The tube has a first borehole that extends downhole through the base. The tube is perforated to allow cement slurry to pass from the casing into the first borehole. A cementing plug is configured to seal to the casing uphole of the base. The cementing plug includes a second borehole to receive the tube. The cementing plug includes a covering that extends across at least part of the borehole and that is configured to break in response to contact with the tube.

A well tool attachment includes a tubular body with a bore therethrough extending along a longitudinal axis, wherein the tubular body is configured to seat in a shoe track of a well casing. A plurality of partitions are suspended from the tubular body, dividing the bore of the tubular body into a plurality of segments extending axially through the tubular body. The partitions are configured to break up cement slurry entering the bore of the tubular body into a plurality of cement segments to facilitate drilling after downhole cement sets.

A well tool attachment includes a tubular body with a bore therethrough extending along a longitudinal axis, wherein the tubular body is configured to seat in a shoe track of a well casing. A plurality of partitions are suspended from the tubular body, dividing the bore of the tubular body into a plurality of segments extending axially through the tubular body. The partitions are configured to break up cement slurry entering the bore of the tubular body into a plurality of cement segments to facilitate drilling after downhole cement sets.

The present disclosure relates to a cementing plug comprising a first plug body (bottom plug), a second plug body (top plug), and a plurality of cleaning portions. The first plug body comprises: a first body provided therein with a chamber opening towards a lower end thereof, and an upper end of the first body being provided with a pressure portion; and an anti-rotation portion provided on an inner wall of the first body, and capable of being connected to slurry entering the chamber to limit a rotation of the first plug body. The second plug body comprises a second body. The plurality of cleaning portions is provided on outer sidewalls of the first body and the second body along a length direction thereof, for scraping off residuals (mud cake) on an inner wall of a casing.

A casing string is augmented with one or more variable flow resistance devices or vibrating tools to facilitate advancement of the casing and distribution of the cement in the annulus once the casing is properly positioned. Vibrating tools in the form of plugs can be pumped down and landed inside the casing string. The method includes vibrating the casing string while advancing the casing down the wellbore or while the cement is pumped into the annulus, or both. After the cementing operation is completed, the devices may be drilled out or retrieved with fishing tools to reopen the casing string for further operations. One or more wipers may be provided on the plugs, but the section housing the flow path may be free of wipers to allow the size and flow capacity of the flow path to be optimized.

An example system for isolating cement slurry from drilling fluids includes a tool configured for installation on a landing collar of a casing. The tool includes a base that conforms to an inner circumference of the casing and a tube that extends uphole from the base. The tube has a first borehole that extends downhole through the base. The tube is perforated to allow cement slurry to pass from the casing into the first borehole. A cementing plug is configured to seal to the casing uphole of the base. The cementing plug includes a second borehole to receive the tube. The cementing plug includes a covering that extends across at least part of the borehole and that is configured to break in response to contact with the tube.

An expansion system is assembled by coupling a piston assembly and a solid cone assembly to an adjustable cone assembly within an expandable tubular having inner sleeve disposed in a portion thereof. The expansion system is run into a wellbore. The piston assembly is activated to move the solid cone assembly downward through the inner sleeve so as to expand the inner sleeve and the portion of the expandable tubular having the inner sleeve. The adjustable cone assembly is shifted from a retracted position to an expansion position within the inner sleeve. The adjustable cone assembly is moved upward through expandable tubular while leaving the solid cone assembly and the inner sleeve coupled to expandable tubular. The solid cone assembly and the inner sleeve may be drilled or milled.