Abstract: A method of pressure testing a casing string in a reverse cementing operation in a wellbore can include: introducing the casing string and a downhole tool installed within the casing string into the wellbore, wherein the downhole tool comprises a fluid flow path defined by an inner diameter of the downhole tool; introducing a cement composition into an annulus located between a wall of the wellbore and an outside of the casing string; causing the fluid flow path of the downhole tool to close against fluid flow from the annulus into at least a portion of the casing string; and increasing pressure within the portion of the casing string that is closed against fluid flow from the annulus. The fluid flow path can be closed by shifting an inner sleeve to close a flapper valve or flow ports, a bridge plug, a packer, or a ball and a ball seat.

Abstract: A dual plug system comprises a bottom plug and a top plug. The bottom plug comprises, a bottom plug mandrel, a plurality of first fins, and a first seat. The plurality of first fins is disposed between a first end and a second end of the bottom plug mandrel, and the first seat is disposed at the second end The top plug comprises a first end and a second end. The top plug further comprises a top plug mandrel, a plurality of second fins, a collar, and a sleeve. 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, and the collar is coupled to the top plug mandrel The dual plug system further comprises a connector, wherein the connector is coupled to the first end of the top plug.

Abstract: A buoyancy assist tool has an outer case and a sleeve disposed in the outer case. The sleeve is movable from first to second positions in the outer case. A permeable membrane is attached to the movable sleeve at a lower end thereof. A rupture disk is mounted in the outer case. Fluid flow through the permeable membrane detaches the sleeve from the outer case and moves the sleeve from the first to the second position. In the second position, the sleeve creates an open bore for the passage of downhole tools therethrough.

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: A cementing tool has an outer housing defining a central flow passage and a plurality of housing flow ports through a wall thereof. An opening sleeve has first and second opening sleeve faces exposed to housing pressure. The first opening sleeve face has a greater surface area than the second opening sleeve face. The pressure differential created is such that the sleeve will move from a first position to a second position in which flow through the plurality of housing flow ports is permitted. The cementing tool has an opening seat defined on the opening sleeve. The opening sleeve may also be moved from the first to the second position as a result of the engagement of the opening plug with the opening seat and an application of pressure thereabove.

Abstract: A reverse cementing tool has an outer case connected in a casing string. A dual stage actuating sleeve is disposed in the outer case and is operable in a first stage actuation to open a cement flow path from a well annulus to a central flow passage of the reverse cementing tool. In a second stage actuation the cement flow path is closed. The actuating sleeve includes inner and outer sleeves in the outer case. The inner and outer sleeves move in opposite directions in the outer case to first open, and then close the cement flow path.

Abstract: A method of anchoring a housing to an inner diameter of a tubing string can include: installing an anchoring assembly at an end of the tubing string, the anchoring assembly comprising: a body; the housing; an installation sleeve; a rotating sleeve in threaded connection with the housing and the installation sleeve; and a plurality of anchoring buttons located within a plurality of cutouts on the housing; causing movement of the body along a longitudinal axis of the tubing string towards the end of the tubing string that causes the plurality of anchoring buttons to circumvolve around a pin and an edge of the anchoring buttons lockingly engages with the ID of the tubing string after circumvolving; releasing both of the installation sleeve and the rotating sleeve from engagement with the tubing string, the body, and the housing; and removing the installation sleeve and the rotating sleeve from the anchoring assembly.

Abstract: A dual valve downhole tool for reverse cementing in a wellbore can include: a body configured to fit within a casing string; an inner sleeve located within the body; a first valve located within the body and configured to open and close a fluid flow path through the body, and wherein the first valve is configured to be in an open position during placement of the downhole tool in the wellbore; and a second valve located within the body and configured to open and close the fluid flow path through the body, wherein the second valve is configured to be in a closed position during placement of the downhole tool in the wellbore, and wherein shifting of the inner sleeve after placement of the downhole tool closes the first valve and opens the second valve. Reverse cementing can commence after the second sleeve has converted to the open position.

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: A poppet valve having an elongated tubular housing and an internal bore. A flange extends within the internal bore supporting an interior tubular member. The interior tubular member itself has a central aperture and an inwardly protruding lip extending into the central aperture. A stem having collet fingers may be partially received in the central aperture of the interior tubular member. The collet fingers have a protrusion which is engagable with the inwardly protruding lip. A biasing element is provided biasing the stem toward a first position. An elastomeric seal may be disposed around the stem. When the stem is in a first position the elastomeric seal forms a fluid tight seal preventing fluid flow through the internal bore, and wherein upon application of a predetermined fluid pressure the stem transitions from the first position to a second position, whereby fluid flow is permitted through the internal bore.

Abstract: A valve assembly has a housing defining a flow passage therethrough. A first flapper is disposed in the housing. A first sleeve retains the flapper in an open position. At least one lock ring holds the first sleeve in a first position. A tripping ball engages a plurality of disconnected bodies in the sleeve and a force is applied to move the first sleeve from the first to a second position.

Abstract: A flow assembly is deployed downhole in a casing for a cementing operation. The flow assembly has a spool with an optical cable. As cement is pumped downhole and through the flow assembly, a dart attached to the optical cable on the spool is dragged with the flow of cement. Cement flow is stopped based on signals along the optical cable that the dart is at a desired location downhole.

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 cementing tool has an outer housing defining a central flow passage and a plurality of housing flow ports through a wall thereof. An opening sleeve has first and second opening sleeve faces exposed to housing pressure. The first opening sleeve face has a greater surface area than the second opening sleeve face. The pressure differential created is such that the sleeve will move from a first position to a second position in which flow through the plurality of housing flow ports is permitted. The cementing tool has an opening seat defined on the opening sleeve. The opening sleeve may also be moved from the first to the second position as a result of the engagement of the opening plug with the opening seat and an application of pressure thereabove.

Abstract: A shoe for use with a casing string in a borehole. The shoe may include a first screen positioned within a bore of the shoe or of the casing string near the shoe. The first screen may include orifices sized to prevent the passage of lost circulation material or a material with properties similar to the lost circulation material from outside the shoe through the first screen.

Abstract: A buoyancy assist tool has an outer case with a rupture disk assembly connected therein. The buoyancy assist tool defines the upper end of a buoyancy chamber in a well casing. A sleeve in the outer case traps the rupture disk membrane after it has ruptured to provide full bore flow through the casing.

Abstract: A downhole apparatus comprises a casing string with a degradable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the degradable plug and the degradable plug and the flow barrier defining a buoyancy chamber therebetween. An annular fluid reservoir holds a degrading fluid. The fluid reservoir has first and second rupture disks at upper and lower ends. Fluid from the annular fluid reservoir is communicated to the degradable plug after the first and second rupture disks rupture.

Abstract: A flow assembly is deployed downhole in a casing for a cementing operation. The flow assembly has a spool with an optical cable. As cement is pumped downhole and through the flow assembly, a dart attached to the optical cable on the spool is dragged with the flow of cement. Cement flow is stopped based on signals along the optical cable that the dart is at a desired location downhole.

Abstract: A buoyancy assist tool has an outer case and a sleeve disposed in the outer case. The sleeve is movable from first to second positions in the outer case. A permeable membrane is attached to the movable sleeve at a lower end thereof. A rupture disk is mounted in the outer case. Fluid flow through the permeable membrane detaches the sleeve from the outer case and moves the sleeve from the first to the second position. In the second position, the sleeve creates an open bore for the passage of downhole tools therethrough.

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.