Ram Blowout Preventer
|Brief Introduction to Ram Blowout Preventer:
The ram BOP is an integral part of well controlequipment, featuring flexible closings and openings,easy operation, safe service and simple maintenance.
The ram BOP is designed to seal off the tubularannulus or the well. With the ram BOP in the closedposition, such operations as circulating drilling fluid, re-leasing pressure and killing the well can be performedby means of the spool beneath the BOP or pipelinesconnected to outlet of the BOP body. Under specialcircumstances, the ram BOP can shear the pipe in thehole to seal off the well. If the ram BOP has variablebore rams, it can seal off the annular space betweenthe casing and the pipes whose sizes are at the mini-mum and maximum of the ram’s range.
2、 Structural Features
（1） Body Structure；
1）Shape. The BOP has a body similar to squareshape, having a vertical bore through which the pipescan pass and ram cavities in which the rams move inthe horizontal direction
2）Connection types. The BOP are offered withstudded, flanged and hubbed top and bottomconnections. The sizes of flanges, bolts, clamps andring grooves all conform to API 16A.
For dual-face ram, the upper face and lower faceof the ram are exactly symmetrical. Various drilling toolswith different sizes is only necessary to replace the semi-annular rubber sealing ring and ram compact, the oth-ers can be interchanged;
（3）Seal of Ram
The seal of the ram putting into effect of the pack-ing wellhead must depend on four seals. i.e. the sealbetween the top of the ram and housing, the seal be-tween the fore-end of the ram and the pipeline, the sealbetween the housing and the side-gate and the sealbetween piston rod and the side-gate.
（4）Locking Mechanism of Ram
The manual locking device depends on manpower torotate handwheel to close or lock the rams. It shall benoted that the manual locking device only can be usedto close rams. Be sure to make the manual locking de-vice return to the original position to unlock the ramsbefore opening the rams with hydraulic pressure.
| Operating Requirements：
（1）As blowout happens, full-enclosed ram BOP isable to pack off an empty well or semi-enclosed ram isable to pack off the drilling tool with the same size asthe ram. If long time of well close is necessary, the ramshould be locked up manually and a nameplate shouldbe provided for indication. The wheel is pulled to thestation prior to turned back at 1/4~1/2 circuit.
（2）Before opening rams, check whether the manual locking device is unlocked or not. Every time after open-ing rams, check whether rams are in the full open posi-tion or not in order to prevent pipes from damaging rams
（3）Release pressure in the control manifold before opening or closing the door in order to prevent damageto O-Ring of the hinge. If the door is not in the full openposition or its bolts not installed well, it is not allowed toopen or close rams with hydraulic pressure
Annular Blowout Preventer
| Annular BOP：
Used in conjunction with hydraulic control system,the annular BOP seals off the annulus of different sizeswhen drilling tool is set in the hole, when there is nodrilling tool in the hole, it can also seal off the wellhead.If well blowout happens during the coring and measur-ing operation, it can seal off the annular spaces beteenthe well barrel and kelly, coring tool, cable and steelrope etc. matched with pressure-relief valve and buffertank, it can force-execute the running/retrieving drilloperation through butt-weld drilling-rod at 18 degreewithout fine thread.
A hydraulic control system is used to close or openthe annular preventer. when it is closed, high pressureoil is directed to the closing chamber positioned in thelower side of the piston, causing the piston to moveupward. The rubber core is compressed by the movingpiston. Because the annular BOP has a cap, the pack-ing unit can not move upward and only can move to-ward the center of the well to pack off a string or seal offthe well.
When well open is required, operate the reversalvalve to direct high pressure oil from the upper oil-portinto the chamber in the upper side of the pistion so asto push the pistion to move down, and then the closingchamber is relieved, the squeese pressure at the coneof rubber core is removed, the wellhead is opened.
（1）The annular BOP can be used to seal off a wellwhere the drill pipe is in use if the well blowout.However, the annular BOP cannot be closed for along time, because the packing unit is easy to bedamaged and the BOP itself has no lockingmechanism.
（2）It is necessary to use a drilling tool with 18 bevel when running/retrieving drill of operation with BOP,running/retrieving drill should be slow pass throughthe nipple and all the rubber protecting collar onthe drilling tool should be discharged off.
（3）With the annular BOP in the closed position andshut-in pressure kept below 5MPa, the string canbe moved either up or down, but mustn’t be rotated.
（4）It is forbidden to open the annular BOP to relievethe pressure out of the well to avoid rubber coredamage
（5）Be sure to check whether the annular BOP is inthe full open position or not every time after openedin order to prevent damage to the packing unit
（6）Clean the inside of the BOP after well cementingoperation is completed in order to keep its clos-ings and openings flexible.
（7）More attention shall be paid to ring gaskets andgasket grooves during installation of the BOP or itsremoval from the service
（8）After entering the destination layer, running/retriev-ing drill once should be accompanied with test ofwell-enclosed with drilling tool once, and inspectthe effect of well enclosed with rubber core, if be-yond the requirement, it should be replaced.
（9）Periodically perform pressure test on the annularBOP in accordance with applicable standards