Equipment Category 01

Well Control & Pressure-Control Equipment

Browse well-control and pressure-control equipment for drilling, workover and well-intervention operations. Review current listings by equipment type and condition, or submit an RFQ for a specific requirement.

02Technical Guide

Well-control equipment works as a system

Well-control equipment provides the pressure barriers, controlled flow paths and operating functions required to shut in, circulate and manage an influx during drilling and other well operations.

A BOP stack cannot be evaluated by bore size and working pressure alone. Its suitability also depends on the well design, tubular programme, expected surface pressure, well fluids, required shearing capability, connection interfaces, control-system capacity and choke and kill arrangement.

FactorWhat must be considered
Pressure and temperatureExpected surface pressure, test pressure and operating temperature
Tubular programmePipe sizes, tool joints, casing dimensions and hang-off loads
Ram functionsSealing range, shearing capability and post-shear sealing
ConnectionsBore, flange or hub type, pressure rating and stack compatibility
Control systemRequired functions, usable accumulator volume and response
Service environmentWell fluids, sour service, offshore conditions and regulatory requirements
03Technical Guide

Different barriers perform different functions

Annular preventers

Annular preventers seal around a range of tubular sizes and shapes within their qualified operating limits. Selection depends on bore, pressure, packing-element type, temperature, fluid compatibility and stripping requirements.

Pipe and variable-bore rams

Fixed-bore pipe rams seal around a specified tubular size. Variable-bore rams cover a defined diameter range, but should not be assumed to seal around every tubular passing through the stack.

Blind and blind-shear rams

Blind rams seal an unobstructed bore. Blind-shear rams are designed to shear specified tubulars and subsequently provide a pressure seal.

Casing-shear and specialized rams

Some applications require dedicated casing-shear, hang-off, stripping, test or intervention ram assemblies. Their functions and operating limits must be confirmed from the manufacturer's documentation.

Shear capability must be verified — not assumed. Tubular size, wall thickness, grade, tool-joint position, blade condition, available closing force and supporting calculations or test evidence all matter.
04Technical Guide

No single BOP stack suits every well

Surface systems

  • annular and ram BOPs
  • drilling spools
  • choke and kill outlets
  • connectors and transition spools
  • surface hydraulic-control equipment

Subsea systems

  • lower BOP stack
  • lower marine riser package
  • subsea connectors and accumulators
  • control pods
  • emergency-disconnect functions
  • ROV intervention interfaces

The stack arrangement should be defined against the well-control philosophy, tubular programme, required shearing and sealing functions, rig envelope and applicable operator requirements.

05Technical Guide

Control, circulation and diversion

Choke & Kill Equipment

Provides controlled flow paths into and out of the well during circulation and pressure-control operations. Pressure rating, bore, configuration, materials, erosion exposure, end connections and flexible-line service level should be confirmed for the complete system.

BOP Control Units

Store and deliver the hydraulic energy required to operate the BOP stack and associated valves. Suitability depends on usable accumulator volume, pump capacity, redundancy, operating pressure, control functions and response requirements — not bottle count alone. Also searched as a Koomey unit.

Diverter Systems

Direct shallow formation flow away from the rig rather than shutting in and containing full well pressure. Vent-line arrangement, valve sequencing, control logic and rig layout are integral to the system.

Rotating Control Devices

Provide a dynamic seal around the drill string for managed-pressure, underbalanced and other closed-loop operations. An RCD complements the well-control system and should not automatically be presented as a substitute for conventional BOP functions.

06Technical Guide

Select the wellhead around the well design

The wellhead supports and suspends casing and tubing strings, seals the annuli and provides pressure-containing interfaces throughout well construction and production. Selection begins with the casing and completion design — not with an isolated flange size or working-pressure rating.

01

Casing programme and loads

Confirm casing sizes, weights, connections, suspended loads, pressure loads and external mechanical loads.

02

Pressure and temperature

Confirm the required rating for each stage of well construction and production. The capacity of the complete assembly is limited by its components and interfaces, not only the main housing.

03

Materials and service environment

Evaluate expected fluids, hydrogen sulphide, carbon dioxide, chlorides, temperature and other corrosive or embrittling conditions.

04

Configuration and installation

Define whether the system is conventional spool, compact or unitized, threaded, slip-on, weld-on or mandrel-hanger based, together with the required installation tooling and access.

05

Interface compatibility

Verify compatibility among the BOP, casing hangers, tubing head, tubing hanger, Christmas tree, sealing systems and any required adapters.

Components from different manufacturers should not be assumed interchangeable without dimensional and engineering verification.
07Reference

Relevant API standards

StandardPrincipal relevance
API Specification 16ARam and annular BOPs, drilling spools, adapters and connectors
API Specification 16CChoke and kill equipment
API Specification 16DBOP and diverter control systems
API Standard 53BOP equipment systems used in drilling wells
API Specification 6AWellhead and Christmas tree equipment
API Standard 16ARRepair and remanufacture of drill-through equipment
Additional applicable standards
  • API Specification 16BIntervention well-control equipment
  • API Specification 16RCDRotating control devices
  • API Standard 64Diverter equipment systems
  • API Standard 6ARRepair and remanufacture of wellhead and tree equipment
  • API Specification 17DSubsea wellhead and tree equipment
  • API Specification 16FMarine drilling-riser equipment and associated interfaces
The applicable standard, edition, addenda, equipment class and purchaser requirements must be confirmed for each application. Additional ISO, NORSOK, regional regulatory, operator-specific and sour-service material requirements may also apply.
08Buyer Guidance

Evaluating used, surplus or refurbished equipment

Available equipment can reduce procurement lead time, but its configuration, condition and documentation must be assessed against the intended service.

Equipment identity

  • manufacturer and model
  • serial number and legible nameplate
  • original manufacturing date
  • complete equipment configuration

Technical documentation

  • original data book and drawings
  • certificates and material records
  • pressure- and function-test records
  • maintenance and inspection history
  • repair or remanufacture documentation

Current condition

  • elastomer age and storage conditions
  • preservation status
  • known defects
  • recent photographs
  • readiness for physical inspection
“Refurbished” should be supported by a defined scope of work. Cleaning, painting and replacing visible seals are not equivalent to a controlled repair or remanufacturing process.

Looking for specific well-control equipment?

Submit the required equipment type, configuration, ratings, documentation and delivery schedule. WELLENGI can also approach relevant equipment owners and suppliers when the required item is not currently listed.

What to include
  • intended operation
  • surface or subsea application
  • nominal bore size
  • working pressure and temperature range
  • expected well fluids
  • sour-service requirements
  • applicable API or other standards
  • required BOP stack configuration
  • pipe and ram sizes
  • required shear capability
  • connection sizes and types
  • control-system requirements
  • certification and documentation requirements
  • acceptable equipment condition
  • inspection or recertification requirements
  • operating country and location
  • required delivery date
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Need help evaluating the equipment?

Request independent support with specification review, equipment comparison, documentation assessment or inspection-scope development.

Final equipment acceptance remains subject to the applicable engineering assurance, inspection, testing and operator-approval process.

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Have surplus well-control equipment?

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