Hydraulic fracturing plug

A plug configured to isolate formation zones within a wellbore that has a casing, the plug comprising:

• a flow control subassembly configured to control the flow of fluid through the plug, the flow control subassembly comprising:
• a mandrel that includes a central flow passage;
• and
• a valve assembly, wherein the valve assembly comprises:
• a housing defining a valve chamber inside the housing and one or more bypass ports that extend through the housing into the valve chamber;
• a valve seat between the valve chamber and the central flow passage of the mandrel;
• a valve element inside the valve chamber, wherein the valve element is secured to the housing with one or more shear pins when the valve element is in a first position in which the valve element is spaced apart from the valve seat and does not block the bypass port(s);
• and
• wherein the valve element has a half-capsule shape that includes a rounded sealing surface a flat outer face, and a peripheral surface extending between the rounded sealing surface and the flat outer face, the peripheral surface configured to cover the entirety of the bypass port(s) when the valve element is in a second position in which the rounded sealing surface contacts the valve seat;
• an anchoring subassembly configured to secure the plug in the casing of the wellbore;
• and
• a sealing device configured to prevent flow around the plug within the casing of the wellbore.

A plug configured to isolate formation zones within a wellbore that has a casing, the plug comprising:

• a flow control subassembly configured to control the flow of fluid through the plug, the flow control subassembly comprising:
• a mandrel that includes a central flow passage;
• and
• a valve assembly, wherein the valve assembly comprises:
• a housing defining a valve chamber inside the chamber housing and one or more bypass ports that extend through the housing into the valve chamber;
• a valve seat between the valve chamber and the central flow passage of the mandrel;
• a valve element inside the valve chamber, wherein the valve element is secured to the housing with corresponding shearable threads when the valve element is in a first position in which the valve element is spaced apart from the valve seat and does not block the bypass port(s);
• and
• wherein the valve element has a half-capsule shape that includes a rounded sealing surface a flat outer face, and a peripheral surface extending between the rounded sealing surface and the flat outer face, the peripheral surface configured to cover the entirety of the bypass port(s) when the valve element is in a second position in which the rounded sealing surface contacts the valve seat;
• an anchoring subassembly configured to secure the plug in the casing of the wellbore, wherein the anchoring subassembly includes upper slips and lower slips;
• and
• a sealing device configured to prevent flow around the plug within the casing of the wellbore, wherein the sealing device is located between the upper slips and the lower slips.