A set of variable bore rams in a preventer provides back-up for tapered strings. The inserts rotate inward when the rams are closed, the steel providing support for the rubber which seals the pipe. The Flex-packer and Flex-packer —NR narrow range are a variation in design with stacks of metal inserts bonded to the elastomer. As the ram is energised the proper set of inserts is forced against the pipe extruding rubber to create a seal.
The Dual-bore Flex-packer is designed to seal on three different pipe sizes in two different packer bores. A block of polyethylene is inserted into the ram packer to increase wear resistance. The wedgelock is a hydraulic mechanism which allows the BOP to be locked in the closed position remotely.
The wedgelock assembly is attached to the BOP in place of the normal lock screw housing. With the ram in the closed position, energising the wedgelocks causes the floating wedge to slide forward and wedge the tapered tail rod in the closed position. This effectively locks the Ram in position even if hydraulic closing pressure is lost or removed from the operating piston. In order to open the ram the wedgelocks must first be unlocked by applying unlock pressure which forces the wedge back into the wedgelock housing.
The tail rod of the ram is then free to move back. The operating system can be interlocked using sequence caps to ensure the wedgelocks are opened before pressure is applied to open the preventer. In subsea applications, a pressure balance chamber is used in conjunction with the wedgelocks to eliminate the possibility of hydrostatic pressure unlocking the wedgelocks.
Wedgelocks are normally only used during well control operations and in special instances such as when the lower marine riser package LMRP is disconnected on a floating rig. The Hydril ram type preventer is similar in operation and performance to the other ram preventers detailed in this section. Hydraulic passages and fluid connectors are contained within the BOP body.
Operating fluid enters the BOP through the opening and closing ports in the body and is ported from the body through the fluid hinge and on to the operating cylinder. Normal operating pressure is psi. The ram upper surface is recessed to prevent seal seat wear while opening and closing the rams and to prevent scoring of the seal seat from a damaged ram.
Energising of the upper ram seal and the seal seat is produced during the final off portion of the ram stroke. Hydraulic Fluid Circuit. Hydril produce pipe, blind, variable, shear and offset rams. Rams include a large volume of feedable rubber in reserve between extrusion plates. The Ram blocks are rebated to slide on guide rails within the ram bonnet compartments. Certain rams have hardened steel inserts for hanging off operations. Seals and front packers are simple to change out in the field.
The front packer has a large volume of feedable rubber bonded to heavy anti-extrusion plates. As the rams meet face to face the plates on the front packer cause pressure in the rubber to initiate seal off. A new front packer provides a large clearance between the ram block and the pipe.
As wear increases the clearance reduces as the ram blocks move closer to the pipe. The useful life of the front packer is complete when the clearance between the pipe and the ram block is zero.
MPL automatically locks and maintains the ram closed even in the event of loss of closing pressure. Front packer seal wear requires a different ram locking position with each closure to ensure an effective seal off and the lock is only engaged when the ram reaches this position.
A mechanical lock is automatically set each time the ram is closed. Locking and unlocking of the MPL are controlled by a unidirectional clutch mechanism and a lock nut. Motion of the piston and tail rod during closing and opening of the rams causes the lock nut to rotate freely until the ram has come to a stop.
The clutch assembly permits or prevents lock nut rotation. Once the rams are closed the clutch engages and opening pressure is then required to disengage the clutch in order to open the rams.
Hydraulic opening pressure disengages the clutch plates to permit the lock nut to rotate freely as the ram opens. MPL is activated each time the rams are closed. The 'SL' BOP incorporates a mechanical locking system for use on surface stacks and has two types of automated locking systems for use subsea.
Any standard oil field accumulator with an operating pressure of psi can be used. A psi test is applied to all Model 'SL' cylinders at the factory, however this pressure is not recommended for field use.
The hydraulic operating fluid should be water soluble and have a viscosity of between SSU at F. Headers: Both accumulator and control valve headers are machined complete from non-welded mechanical tubing and are rated 5, psi. Pumps: Options include electric, gasoline, diesel, air powered or manual hand operated. All pump systems come with. The BOPs are designed and manufactured in full API 16A oilfield double ram manual bop blowout preventer.
The annular blowout preventer dynamic seal adopt lip structure of. Seaco Oilfield Equipment Co. Application area: is is used for forming BOPS It's also widely used in medicine. This machine has. Ltd [Shandong,China] Active Member. This machine has a. It combines the material sending, heating, forming and cutting into one process.
It has three operation models. BOPS thermoforming machine main features A combanition of mechanical, electric and puematic components, and the whole systen was controlled bu amicro PLC, which canbe operated in man-interface. A blowout begins as a Kick entry of subsurface formation fluids into the wellbore. What distinguishes a kick from a blowout is that a kick can be controlled while a blowout is uncontrollable.
We have already discussed two of the defenses against kicks when we discussed drilling fluids when we listed the objectives of the drilling fluid:. In the first objective re-quoted above, if we can keep the pressure exerted by the drilling mud greater than the pore pressure, then we know that fluids will flow in the direction of the mud to the formation.
This cannot always be achieved. For example, if we drill through a natural fracture or if our mud density is too great and we inadvertently fracture one formation, then we may lose large quantities of the drilling fluid into the fracture Lost Circulation. In this situation, instead of having the full weight of the mud column exerting pressure on a second porous and permeable formation, we may only have a fraction of the oil column height exerting a lower pressure on that second formation.
In the second objective re-quoted above, if we deposit an impermeable Drill Cake filter cake across an otherwise porous and permeable formation, then for a slightly Underbalanced Pressure drilling fluid pressure lower than the formation pressure we have created a seal between the wellbore and the formation.
Again, this is not a Failsafe System because at greater underbalanced pressures, the higher formation pressures may be able to displace the drill cake. The two previously discussed methods are used to help prevent a kick from occurring, but as mentioned they are not always successful, and kicks may still occur. Then they would wait Oct 14, Side ram with safe working tray—a Cameron exclusive. Single BOP. Double BOP. Double un BOP.
U Il Blowout Preventer. To order specify, part BOP Annulars. BOP Handling. DM - Double Manual. Blowout Preventers. Hydril is a registered trademark of Hydril Company. Bowen is a trademark of. National Oilwell Varco. Cameron is a registered trademark of Cooper Cameron.
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