Annular BOP with packing element used in oilfield

Description

Goldenman API 16A Annular BOPs are hydraulically operated well-control devices designed to seal around drill pipe, tubing, casing, drill collars, tool joints and other tubular profiles positioned in the wellbore.

Depending on the selected model and approved operating procedure, the annular packing element can also close on an open wellbore when no tubular is present.

The available series includes spherical and tapered packing-element designs with bore sizes from 179.4 to 539.7 mm and rated working pressures from 2,000 to 10,000 psi.

Each Annular BOP is selected according to the BOP stack bore, pressure rating, tubular outside diameter, control-system capacity, operating temperature, drilling-fluid chemistry, H₂S conditions and required packing-element performance.

Product Highlights

• Manufactured according to applicable API Spec 16A requirements
• API-certified Annular BOP equipment
• Spherical and tapered packing-element designs
• Bore sizes from 179.4 to 539.7 mm
• Rated working pressures from 2,000 to 10,000 psi
• Bolted or clamp-type upper-housing connections
• Hydraulic opening and closing
• Sealing around multiple tubular outside diameters
• Open-bore sealing capability in approved configurations
• Packing elements and replacement sealing parts available
• Opening and closing volumes provided by model
• Onshore and offshore BOP stack applications
• Factory pressure and functional testing
• Project documentation and third-party inspection support

What Is an Annular BOP?

An Annular Blowout Preventer is a hydraulically operated well-control device installed in the BOP stack.

Its reinforced elastomeric packing element is compressed inward by a hydraulic piston to form a pressure seal around the tubular passing through the bore.

Depending on the equipment design and approved operating procedure, an annular BOP can seal around:

• Drill pipe
• Tool joints
• Drill collars
• Tubing
• Casing
• Wireline or other approved profiles
• An open wellbore

The annular BOP provides greater sealing flexibility across different outside diameters than a fixed-size pipe ram. However, it does not replace the specific functions of pipe rams, variable-bore rams, blind rams or shear rams in a complete BOP stack.

Main Applications

Goldenman Annular BOPs can be configured for:

• Oil and gas drilling rigs
• Land and offshore drilling
• Workover and well-servicing operations
• Well shut-in
• Pressure containment around tubulars
• Open-bore well isolation
• Controlled stripping operations
• Snubbing and pressure-control applications
• BOP stack replacement projects
• New drilling-rig well-control packages

The suitability of a specific model for stripping, rotating pipe or sealing around a tool joint must be confirmed through the equipment manual and approved well-control procedure.

Annular BOP Structure Types

Model A — Tapered Packing Element

The tapered packing-element design shown on the original product page includes:

• Upper housing
• Wear plate
• BOP body
• Hydraulic piston
• Tapered packing element
• Anti-dust ring
• Supporting cylinder

The tapered geometry converts piston movement into inward compression of the packing element.

This design is available in several high-pressure models, including configurations rated up to 10,000 psi.

Model D — Spherical Packing Element

The spherical packing-element design includes:

• Upper housing
• BOP body
• Hydraulic piston
• Spherical packing element
• Anti-dust ring

The spherical packing element deforms inward around the tubular or open bore as hydraulic pressure moves the piston.

Final selection between tapered and spherical designs should be based on the required bore, working pressure, packing-element availability, control-system compatibility and operating procedure—not on packing shape alone.

General Technical Specifications

Parameter	Available Specification
Product name	Annular Blowout Preventer
Applicable standard	API Spec 16A, applicable current edition
Structure options	Spherical or tapered packing element
Bore range	179.4–539.7 mm
Working pressure	14–70 MPa / 2,000–10,000 psi
Upper housing connection	Bolted or clamp-type
Operation	Hydraulic opening and closing
Primary sealing component	Reinforced annular packing element
Main service	Drilling and workover well control
Applicable profiles	Drill pipe, tubing, casing, drill collars and approved tubular profiles
Open-bore sealing	According to the selected model and approved procedure
Stripping capability	According to the model, the tubular profile and operating procedure
Packing-element material	Selected according to service conditions
BOP stack connection	Project-specific
Control-system requirement	Based on the opening and closing volume
Certification	API certificate
Inspection	Factory and third-party inspection as specified

Model A Tapered Annular BOP Specifications

Model	Bore	Working Pressure	Closing Volume	Opening Volume	Reference Weight
FHZ18-70	179.4 mm	70 MPa / 10,000 psi	36 L	27 L	6,293 kg
FHZ28-70	279.4 mm	70 MPa / 10,000 psi	67 L	66 L	12,290 kg
FHZ35-70	346.1 mm	70 MPa / 10,000 psi	116 L	117 L	15,190 kg
FHZ43-35	425.4 mm	35 MPa / 5,000 psi	134 L	134 L	14,100 kg
FHZ54-14	539.7 mm	14 MPa / 2,000 psi	95.3 L	94.5 L	7,660 kg

Model D Spherical Annular BOP Specifications

Model	Bore	Working Pressure	Closing Volume	Opening Volume	Reference Weight
FH18-21	179.4 mm	21 MPa / 3,000 psi	21 L	15 L	1,433 kg
FH18-35	179.4 mm	35 MPa / 5,000 psi	21 L	15 L	1,520 kg
FH23-21	228.6 mm	21 MPa / 3,000 psi	34 L	22.8 L	2,398 kg
FH23-35	228.6 mm	35 MPa / 5,000 psi	42 L	33 L	2,986 kg
FH28-21	279.4 mm	21 MPa / 3,000 psi	50 L	39 L	2,950 kg
FH28-35	279.4 mm	35 MPa / 5,000 psi	To be confirmed	72 L	4,675 kg
FH35-21	346.1 mm	21 MPa / 3,000 psi	94 L	69 L	5,738 kg
FH35-35	346.1 mm	35 MPa / 5,000 psi	94 L	69 L	6,415 kg
FH48-35	425.3 mm	35 MPa / 5,000 psi	220 L	171 L	16,000 kg
FH53-21	427 mm*	21 MPa / 3,000 psi	173 L	110 L	6,994 kg
FH54-35	539.7 mm	35 MPa / 5,000 psi	241 L	181 L	20,230 kg

*The model designation and bore data for FH53-21 should be confirmed against the current factory datasheet before publication or quotation.

All listed weights are reference values. Final dimensions, connection details, operating volume and weight are governed by the approved product drawing and datasheet.

How to Select the Correct Annular BOP

1. Match the BOP Stack Bore

The Annular BOP bore must be compatible with:

• Wellhead and drilling spool bore
• Ram BOP bore
• Drilling riser or stack bore
• Maximum tubular and tool-joint outside diameter
• Required internal clearance
• Planned casing and completion program

Selection should not be based only on the nominal drill pipe size. Tool-joint, drill-collar and casing-coupling outside diameters may be significantly larger.

2. Confirm the Required Working Pressure

The rated working pressure should be selected from:

• Maximum anticipated surface pressure
• BOP stack rating
• Well-control design pressure
• Shut-in pressure
• Pressure-test requirements
• End-user and regulatory specifications

All components in the pressure-control flow path must have compatible ratings.

3. Select Spherical or Tapered Packing-Element Design

Both structures can provide annular sealing, but they have different body designs, piston arrangements, packing geometries and replacement-part requirements.

The buyer should consider:

• Existing BOP stack design
• Preferred packing-element type
• Available installation height
• Bore and pressure requirements
• Opening and closing volume
• Control-unit capacity
• Packing-element inventory
• Maintenance experience
• Replacement compatibility

A spherical packing element cannot be assumed to be interchangeable with a tapered packing element.

4. Check the Maximum Tubular and Tool-Joint OD

The buyer should provide the largest outside diameter expected to pass through or be sealed by the Annular BOP.

This may include:

• Drill pipe tool joint
• Drill collar
• Casing coupling
• Bottom-hole assembly
• Completion tool
• Workover string
• Wireline pressure-control equipment

The packing unit’s sealing and stripping capability must be verified for the largest applicable profile.

5. Verify Control-System Capacity

Opening and closing volumes differ substantially by model.

The BOP control system should be checked for:

• Required closing volume
• Required opening volume
• Number of BOPs controlled
• Accumulator usable-fluid volume
• Hydraulic operating pressure
• Required closing time
• Simultaneous-function requirements
• Emergency operating reserve

A control unit should not be selected only by nominal accumulator capacity.

6. Define Service Conditions

Provide:

• Minimum and maximum temperature
• Water-based, oil-based or synthetic-based mud
• H₂S and CO₂ conditions
• Drilling-fluid additives
• Expected hydrocarbons
• Pressure exposure
• Stripping requirement
• Storage environment

These conditions affect packing-element compound, dynamic seals, elastomers and corrosion-control requirements.

Packing-Element Selection

The packing element is the primary sealing component and one of the most important consumable parts of an Annular BOP.

Selection should consider:

• BOP model
• Bore size
• Working pressure
• Tubular OD range
• Tool-joint profile
• Operating temperature
• Mud type
• Oil and chemical exposure
• H₂S conditions
• Stripping frequency
• Expected storage period

A packing element should not be ordered using only the general description “annular BOP rubber.”

For replacement orders, provide:

• BOP manufacturer
• BOP model
• Bore and pressure rating
• Existing packing-unit part number
• Packing-unit dimensions
• Compound or service requirement
• Clear photographs
• Previous operating conditions

Stripping and Tubular Movement

An Annular BOP may be used for controlled stripping when permitted by the BOP design and approved well-control procedure.

During stripping, hydraulic closing pressure is adjusted to maintain a seal while allowing controlled tubular movement through the packing element.

The procedure must account for:

• Tubular outside diameter
• Tool-joint profile
• Well pressure
• Packing-element condition
• Hydraulic closing pressure
• Lubrication
• Pipe speed
• Expected element wear
• Control-system response

The Annular BOP should not be operated at maximum closing force unnecessarily, because excessive force can increase packing-element wear and tubular damage.

Procurement Considerations

Complete BOP Scope

The quotation should identify whether it includes:

• Complete Annular BOP
• Upper and lower connections
• Packing element
• Piston seals
• Wear plate
• Anti-dust ring
• Supporting cylinder
• Hydraulic fittings
• Lifting points or handling accessories
• Companion flanges or clamp components
• Studs, nuts and ring gaskets
• Recommended spare-parts kit
• API and inspection documentation

Replacement Compatibility

For an existing BOP replacement, confirm:

• Original manufacturer and model
• Bore size
• Pressure rating
• Upper and lower connection
• Overall height
• External diameter
• Hydraulic-port location
• Opening and closing volume
• BOP stack interface
• Control-system capacity
• Packing-unit part number

The same bore and pressure rating do not guarantee dimensional interchangeability.

Packing-Element Inventory

Remote or continuous drilling projects should normally maintain spare packing elements and seal kits onsite.

Spare-part planning should consider:

• Number of operating BOPs
• Well duration
• Drilling-fluid type
• Stripping frequency
• Storage conditions
• Local replacement-part availability
• Manufacturing and shipping lead time

API Certification and Quality Control

Goldenman supplies Annular BOPs with API certification under the applicable API Spec 16A scope.

Manufacturing and inspection controls may include:

• Material-certificate verification
• Heat-number traceability
• Chemical and mechanical property review
• Dimensional inspection
• Hardness testing
• Ultrasonic examination where required
• Magnetic-particle or liquid-penetrant examination
• Pressure-containing body inspection
• Piston and sealing-surface inspection
• Packing-element verification
• Hydraulic opening and closing test
• Hydrostatic body test
• Sealing and pressure-holding test
• Hydraulic-port and leakage inspection
• Product-marking verification
• Coating and preservation inspection
• Final documentation review

The final inspection and test scope is determined by the selected model, API requirements, approved quality plan and purchase order.

Factory Acceptance Test

The agreed FAT can include:

• Approved drawing review
• Bill of materials verification
• Material traceability review
• Dimensional inspection
• Bore and connection inspection
• Hydraulic opening and closing
• Closing-volume and opening-volume verification
• Body pressure test
• Packing-element sealing test
• Pressure-holding test
• External leakage inspection
• Functional cycle test
• Product marking inspection
• Coating inspection
• Documentation review

Customer or third-party witness and hold points should be specified before production.

Available Documentation

The documentation package can include:

• API certificate
• Certificate of Conformity
• Approved product datasheet
• General arrangement drawing
• Material certificates
• Heat-treatment records
• NDE reports
• Hardness report
• Dimensional inspection report
• Hydrostatic test report
• Sealing and functional test records
• Packing-element identification
• Operation and maintenance manual
• Recommended spare-parts list
• Packing list
• Third-party inspection report

Frequently Asked Questions

How should buyers choose between a spherical and tapered Annular BOP?

The decision should be based on bore, working pressure, installation dimensions, packing-element availability, control-unit capacity and the existing BOP stack design.

Neither packing shape is automatically better for every application. The selected design must match the approved well-control system and maintenance strategy.

Can one Annular BOP seal around several different pipe sizes?

Yes, an annular packing element can normally seal around a range of tubular outside diameters within the approved model capability.

However, the manufacturer must verify the minimum pipe OD, maximum tool-joint OD, open-bore requirement and any planned stripping operation.

Can an Annular BOP close and seal on an open wellbore?

Many Annular BOP designs can close on an open bore, but this capability must be confirmed for the exact BOP and packing-element configuration.

Open-bore closure should only be performed in accordance with the equipment manual and approved well-control procedure.

Can drill pipe tool joints be stripped through the packing element?

Stripping may be possible when the packing unit is qualified for the tool-joint profile and the procedure controls hydraulic closing pressure, pipe speed and lubrication.

The largest tool-joint OD and profile should be stated before purchase.

Why are opening and closing volumes important when selecting a BOP control unit?

These volumes determine how much hydraulic fluid is required to operate the Annular BOP.

The control unit must provide sufficient usable fluid to operate the complete BOP stack while maintaining the required reserve and operating pressure.

How should the packing-element compound be selected?

Selection should consider temperature, mud type, hydrocarbons, chemical additives, H₂S exposure, stripping requirements and storage conditions.

A packing element selected only by BOP model may not be suitable for the actual well environment.

Can a replacement packing element be ordered using only the BOP bore and pressure?

No. The BOP model, packing-unit design, part number, dimensions and service compound must also be confirmed.

Packing elements from spherical and tapered designs are not interchangeable.

What causes premature Annular BOP packing-element failure?

Common causes include:

• Incorrect elastomer selection
• Excessive hydraulic closing pressure
• Stripping through unsupported tool-joint profiles
• High operating temperature
• Chemical incompatibility
• Damaged tubular surfaces
• Poor storage
• Incorrect installation
• Repeated high-pressure cycling

The failed packing unit and operating records should be reviewed together.

What inspection documents should be supplied with an API 16A Annular BOP?

The package may include the API certificate, material records, NDE reports, dimensional inspection, hydrostatic test report, sealing test report, functional test records and Certificate of Conformity.

The exact documentation scope should be agreed before production.

Information Required for Quotation

Please provide:

• Required Annular BOP model
• Required bore size
• Rated working pressure
• Upper connection
• Lower connection
• Maximum tubular OD
• Maximum tool-joint OD
• Open-bore sealing requirement
• Stripping requirement
• Operating temperature
• Drilling-fluid type
• H₂S and CO₂ conditions
• Preferred spherical or tapered structure
• Required packing-element compound
• Existing BOP stack configuration
• BOP control-unit model and capacity
• Required spare packing elements
• API certificate requirement
• FAT and third-party inspection requirements
• Required documentation
• Quantity
• Destination country
• Delivery schedule

For replacement equipment, also provide the existing nameplate, general arrangement drawing, hydraulic-port locations and product photographs.

Request a Technical Quotation

Goldenman supplies API 16A spherical and tapered Annular BOPs for drilling, workover and well-control systems.

Send your required bore, working pressure, connections, maximum tubular OD, packing-element service conditions and control-system details to:

Email: info@goldenman.com

Goldenman will review the BOP stack requirements and prepare the appropriate model selection, datasheet and commercial quotation.