Abstract: A downhole apparatus comprises a casing string with a frangible disk positioned therein. A flow barrier is connected in the casing string and spaced downwardly from the frangible disk. The frangible disk and the flow barrier define a buoyancy chamber. The sliding sleeve will impact and shatter the frangible disk into a plurality of pieces that will pass downwardly in the casing after the casing has been lowered to a desired depth.

Abstract: Remedial wellbore operations can be performed using metal material coated with a layer that is controllably activated to release the metal material downhole in a wellbore. At least a portion of the wellbore can be plugged or sealed using the metal material.

Abstract: Apparatus, systems, and methods for reverse circulation cementing a tubular string in a wellbore. One such method includes reverse circulating cement slurry down an annulus defined between the tubular string and the wellbore. During the reverse circulation, a flow control device located in the tubular string is closed to prevent, or at least reduce, flow of the cement slurry from the annulus into the tubular string. The closure of the flow control device causes a pressure pulse in the wellbore. After the flow control device is closed, the reverse circulation is stopped. During a time interval between the closure of the flow control device and the stoppage of the reverse circulation, a shock absorber associated with the flow control device absorbs the pressure pulse in the wellbore so that a pressure in the wellbore is maintained within an acceptable range.

Abstract: Systems, methods, and apparatuses of the present disclosure generally relate to dissolvable plugs for separating fluids in a wellbore. A dissolvable plug includes a first end comprising a first fluid barrier. The first fluid barrier includes a polymer film. The dissolvable plug also includes a second end opposite to the first end. The second end comprises a second fluid barrier. The second fluid barrier comprises a polymer film. The dissolvable plug includes a solid structure made of a sand and salt mixture.

Abstract: The disclosure provides a dual plug system, comprising a bottom plug, wherein the bottom plug comprises: a bottom plug mandrel; a plurality of first fins; and a first seat; wherein the plurality of first fins is disposed between a first end and a second end of the bottom plug mandrel, wherein the first seat is disposed at the second end; a top plug, wherein the top plug comprises a first end and a second end, wherein the top plug comprises: a top plug mandrel; a plurality of second fins; a collar; and a sleeve; wherein the plurality of second fins is disposed around the top plug mandrel covering at least a portion of the length of the top plug mandrel, wherein the collar is coupled to the top plug mandrel; and a connector, wherein the connector is coupled to the first end of the top plug.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

Abstract: A downhole apparatus comprises a casing string with a fluid barrier connected in the casing string. A degradable plug is positioned in the casing string above the fluid barrier. The degradable plug and fluid barrier define upper and lower ends of a buoyancy chamber in the casing string. The degradable plug may be degraded to leave an open bore through the casing string after the casing string is lowered into a wellbore.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

Abstract: A reverse cementing apparatus having a reverse cementing body with an internal bore, the reverse cementing body being coupleable to the downhole end of a casing pipe. The apparatus may further have a valve actuable from a closed to an open configuration, the closed configuration obstructing flow of fluid through the internal bore of the reverse cementing body. The valve may be configured to obstruct flow in an uphole direction during deployment but permit flow in the downhole direction. The apparatus further includes a port provided extending through a wall of the reverse cementing valve body from the internal bore to external the reverse cementing body, a fluid communication channel extending from the port to the internal bore. An actuable barrier member may be provided which is actuable to a closed position obstructing flow of fluid through the port upon actuation.

Abstract: A downhole apparatus has a casing string and a degradable plug positioned in the casing string to block flow therethrough. An upper membrane covers an upper end of the degradable plug. The upper membrane is made up of a plurality of separable membranes. A lower membrane covers a lower end of the degradable plug and is comprised of a plurality of separable membranes.

Abstract: Remedial wellbore operations can be performed using metal material coated with a layer that is controllably activated to release the metal material downhole in a wellbore. At least a portion of the wellbore can be plugged or sealed using the metal material.

Abstract: A conductive path can be formed using metal material coated with a layer that is controllably activated to release the metal material downhole in the wellbore. The conductive path can be used to communicate signals or power downhole in the wellbore.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier define a buoyancy chamber therebetween. A debris barrier positioned above the removable plug has a plurality of fragments interspersed in a stretchable material and includes a frangible disc.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

Abstract: Switchable cross-over systems, devices, and methods for cementing well walls are provided. A switchable cross-over device includes a tool body and a flow sleeve. The tool body includes a main tool path separable into uphole and downhole tool paths and an auxiliary chamber containing uphole and downhole annular ports. The flow sleeve is within the auxiliary chamber and movable between conventional and reverse circulation positions. In the conventional circulation position, the uphole and downhole tool paths are in fluid communication and the uphole annular port is in fluid communication with the downhole annular port through the auxiliary chamber. In the reverse circulation position, the flow sleeve forms first and second auxiliary flow paths in the auxiliary chamber, the uphole tool path and the downhole annular port are in fluid communication via the first auxiliary flow path, and the downhole tool path is in fluid communication with the uphole annular port.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug includes a frangible disk. A stretchable connecting ring is connected to the frangible disk and to the casing.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug includes a frangible disk. A stretchable connecting ring is connected to the frangible disk and to the casing.

Abstract: A downhole apparatus has a casing string and a degradable plug positioned in the casing string to block flow therethrough. An upper membrane covers an upper end of the degradable plug. The upper membrane is made up of a plurality of separable membranes. A lower membrane covers a lower end of the degradable plug and is comprised of a plurality of separable membranes.

Abstract: A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

Abstract: A buoyancy assist tool and a fluid barrier in a casing string define a buoyancy chamber therebetween. The buoyancy assist tool has a housing connected in the casing string with a retaining sleeve detachably connected in the housing. The retaining sleeve is movable from a first to a second position in the housing. A flapper disk is positioned in the housing and covers an upper end of the retaining sleeve in the first position of the retaining sleeve. In the second position of the retaining sleeve the flapper disk is in a retracted position out of the flow path through the housing.