Abstract: A system for drilling and/or producing a subsea wellbore comprises a primary BOP comprising a primary ram BOP. The secondary BOP is connectable to a subsea wellhead such that the secondary BOP is positioned between the primary BOP and the subsea well-head, in which the secondary BOP comprises a shear ram BOP.

Abstract: An accumulator for hydraulically actuating subsea equipment includes a hydraulic fluid chamber and a gas chamber. The hydraulic fluid chamber is in fluid communication with the subsea equipment and comprises a hydraulic piston slidably received, at least partially, within the hydraulic chamber. The gas chamber comprises a charge piston slidably received within the gas chamber, the charge piston dividing the gas chamber into a first portion and a second portion. The first portion of the gas chamber is configured to receive ambient hydrostatic pressure therein, and the second portion of the gas chamber is configured to receive precharge gas therein.

Abstract: Systems for accessing a well bore including a BOP stack with a universal intervention interface are disclosed. In some embodiments, the system includes a BOP stack and a valve assembly. The BOP stack has a throughbore and is installable on a well such that the throughbore is in fluid communication with the well bore. The valve assembly is coupled to the BOP stack and includes a fluid flowpath in fluid communication with the BOP stack throughbore, two valves connected in series and disposed along the fluid flowpath, the valves operable to control flow through the fluid flowpath, and a ROV panel including ports accessible by a ROV for operation of the two valves.

Abstract: A subsea connection apparatus to allow connecting a surface blowout preventer stack and riser to a subsea wellhead is disclosed. The subsea connection apparatus uses a single cavity blowout preventer with a set of shearing blind rams. Hydraulically actuated wellhead connectors are secured to the top and bottom of the blowout preventer to allow connection to a subsea wellhead below the subsea connection apparatus and a well head hub profile on the lower end of a riser above the apparatus. A control system can operate both of the hydraulically actuated connectors and the blowout preventer independently. A frangible bore protector is disposed in the bore of the blowout preventer to protect the shearing blind rams from pipe, tools, and fluids being passed through the blowout preventer and can be sheared by the shearing blind rams along with any drill pipe in the bore.

Abstract: A system for drilling and/or producing a subsea wellbore comprises a primary BOP comprising a primary ram BOP. In addition, the system comprises a secondary BOP releasably connected to the primary BOP, the secondary BOP comprising a secondary ram BOP. The primary rain BOP is actuatable by a first control signal. The secondary ram BOP is actuatable by a second control signal. The secondary rain BOP is not actuatable by the first control signal.

Abstract: An accumulator for hydraulically actuating subsea equipment includes a hydraulic fluid chamber and a gas chamber. The hydraulic fluid chamber is in fluid communication with the subsea equipment and comprises a hydraulic piston slidably received, at least partially, within the hydraulic chamber. The gas chamber comprises a charge piston slidably received within the gas chamber, the charge piston dividing the gas chamber into a first portion and a second portion. The first portion of the gas chamber is configured to receive ambient hydrostatic pressure therein, and the second portion of the gas chamber is configured to receive precharge gas therein.

Abstract: A system for drilling and/or producing a subsea wellbore comprises a primary BOP comprising a primary ram BOP. The secondary BOP is connectable to a subsea wellhead such that the secondary BOP is positioned between the primary BOP and the subsea well-head, in which the secondary BOP comprises a shear ram BOP.

Abstract: An accumulator for a subsea blowout preventer unit including a blowout preventer includes a body. The body includes a hydraulic fluid chamber and a gas chamber. The hydraulic fluid chamber has a smaller inner diameter than the gas chamber. The accumulator further includes a hydraulic fluid port in fluid communication between the hydraulic fluid chamber and the subsea blowout preventer, a hydraulic piston slidably and sealingly mounted in the hydraulic fluid chamber, and a charge piston slidably and sealingly mounted in the gas chamber. A pressure port receives pressure to provide a force on the opposite side of the charge piston from the hydraulic piston.

Abstract: Systems for accessing a well bore including a BOP stack with a universal intervention interface are disclosed. In some embodiments, the system includes a BOP stack and a valve assembly. The BOP stack has a throughbore and is installable on a well such that the throughbore is in fluid communication with the well bore. The valve assembly is coupled to the BOP stack and includes a fluid flowpath in fluid communication with the BOP stack throughbore, two valves connected in series and disposed along the fluid flowpath, the valves operable to control flow through the fluid flowpath, and a ROV panel including ports accessible by a ROV for operation of the two valves.

Abstract: A subsea connection apparatus to allow connecting a surface blowout preventer stack and riser to a subsea wellhead is disclosed. The subsea connection apparatus uses a single cavity blowout preventer with a set of shearing blind rams. Hydraulically actuated wellhead connectors are secured to the top and bottom of the blowout preventer to allow connection to a subsea wellhead below the subsea connection apparatus and a well head hub profile on the lower end of a riser above the apparatus. A control system can operate both of the hydraulically actuated connectors and the blowout preventer independently. A frangible bore protector is disposed in the bore of the blowout preventer to protect the shearing blind rams from pipe, tools, and fluids being passed through the blowout preventer and can be sheared by the shearing blind rams along with any drill pipe in the bore.

Abstract: Systems for accessing a well bore including a BOP stack with a universal intervention interface are disclosed. In some embodiments, the system includes a BOP stack and a valve assembly. The BOP stack has a throughbore and is installable on a well such that the throughbore is in fluid communication with the well bore. The valve assembly is coupled to the BOP stack and includes a fluid flowpath in fluid communication with the BOP stack throughbore, two valves connected in series and disposed along the fluid flowpath, the valves operable to control flow through the fluid flowpath, and a ROV panel including ports accessible by a ROV for operation of the two valves.

Abstract: A subsea connection apparatus to allow connecting a surface blowout preventer stack and riser to a subsea wellhead is disclosed. The subsea connection apparatus uses a single cavity blowout preventer with a set of shearing blind rams. Hydraulically actuated wellhead connectors are secured to the top and bottom of the blowout preventer to allow connection to a subsea wellhead below the subsea connection apparatus and a well head hub profile on the lower end of a riser above the apparatus. A control system can operate both of the hydraulically actuated connectors and the blowout preventer independently. A frangible bore protector is disposed in the bore of the blowout preventer to protect the shearing blind rams from pipe, tools, and fluids being passed through the blowout preventer and can be sheared by the shearing blind rams along with any drill pipe in the bore.

Abstract: Methods for deploying a subsea blowout preventer stack system comprising a lower marine riser package, a blowout preventer stack with a first ram blowout preventer, and an additional blowout preventer package releasably coupled to the blowout preventer stack and comprising a second ram blowout preventer. The subsea blowout preventer stack assembly can be deployed by coupling a drilling riser to the lower marine riser package that is releasably connected to the blowout preventer stack. The lower marine riser package and blowout preventer stack are then toward a subsea wellhead and then landed on the additional blowout preventer package that is coupled to the subsea wellhead.

Abstract: A system for drilling and/or producing a subsea wellbore comprises a primary BOP comprising a primary ram BOP. In addition, the system comprises a secondary BOP releasably connected to the primary BOP, the secondary BOP comprising a secondary ram BOP. The primary rain BOP is actuatable by a first control signal. The secondary ram BOP is actuatable by a second control signal. The secondary rain BOP is not actuatable by the first control signal.

Abstract: Methods for deploying a subsea blowout preventer stack system comprising a lower marine riser package, a blowout preventer stack with a first ram blowout preventer, and an additional blowout preventer package releasably coupled to the blowout preventer stack and comprising a second ram blowout preventer. The subsea blowout preventer stack assembly can be deployed by coupling a drilling riser to the lower marine riser package that is releasably connected to the blowout preventer stack. The lower marine riser package and blowout preventer stack are then toward a subsea wellhead and then landed on the additional blowout preventer package that is coupled to the subsea wellhead.

Abstract: A subsea connection apparatus to allow connecting a surface blowout preventer stack and riser to a subsea wellhead is disclosed. The subsea connection apparatus uses a single cavity blowout preventer with a set of shearing blind rams. Hydraulically actuated wellhead connectors are secured to the top and bottom of the blowout preventer to allow connection to a subsea wellhead below the subsea connection apparatus and a well head hub profile on the lower end of a riser above the apparatus. A control system can operate both of the hydraulically actuated connectors and the blowout preventer independently. A frangible bore protector is disposed in the bore of the blowout preventer to protect the shearing blind rams from pipe, tools, and fluids being passed through the blowout preventer and can be sheared by the shearing blind rams along with any drill pipe in the bore.

Abstract: Systems for accessing a well bore including a BOP stack with a universal intervention interface are disclosed. In some embodiments, the system includes a BOP stack and a valve assembly. The BOP stack has a throughbore and is installable on a well such that the throughbore is in fluid communication with the well bore. The valve assembly is coupled to the BOP stack and includes a fluid flowpath in fluid communication with the BOP stack throughbore, two valves connected in series and disposed along the fluid flowpath, the valves operable to control flow through the fluid flowpath, and a ROV panel including ports accessible by a ROV for operation of the two valves.

Abstract: A subsea connection apparatus to allow connecting a surface blowout preventer stack and riser to a subsea wellhead is disclosed. The subsea connection apparatus uses a single cavity blowout preventer with a set of shearing blind rams. Hydraulically actuated wellhead connectors are secured to the top and bottom of the blowout preventer to allow connection to a subsea wellhead below the subsea connection apparatus and a well head hub profile on the lower end of a riser above the apparatus. A control system can operate both of the hydraulically actuated connectors and the blowout preventer independently. A frangible bore protector is disposed in the bore of the blowout preventer to protect the shearing blind rams from pipe, tools, and fluids being passed through the blowout preventer and can be sheared by the shearing blind rams along with any drill pipe in the bore.

Abstract: Methods for deploying a subsea blowout preventer stack system comprising a lower marine riser package, a blowout preventer stack with a first ram blowout preventer, and an additional blowout preventer package releasably coupled to the blowout preventer stack and comprising a second ram blowout preventer. The subsea blowout preventer stack assembly can be deployed by coupling a drilling riser to the lower marine riser package that is releasably connected to the blowout preventer stack. The lower marine riser package and blowout preventer stack are then toward a subsea wellhead and then landed on the additional blowout preventer package that is coupled to the subsea wellhead.

Abstract: An accumulator for a subsea blowout preventer unit including a blowout preventer includes a body. The body includes a hydraulic fluid chamber and a gas chamber. The hydraulic fluid chamber has a smaller inner diameter than the gas chamber. The accumulator further includes a hydraulic fluid port in fluid communication between the hydraulic fluid chamber and the subsea blowout preventer, a hydraulic piston slidably and sealingly mounted in the hydraulic fluid chamber, and a charge piston slidably and sealingly mounted in the gas chamber. A pressure port receives pressure to provide a force on the opposite side of the charge piston from the hydraulic piston.