The ram blowout preventer is one of the key elements of the well control system. It
is mainly used to control the well head pressure during such operations as drilling,
servicing and oil testing to prevent any blow out hazard effectively and ensure safe
operations. Specifically, this ram blowout preventer can perform the following
operations:
1. When there is a pipe string in a well, the circular space between the casing and
the pipe string could be sealed with pipe rams or variable diameter rams with
matched specifications.
2. When there isn’t a pipe string in a well, the wellhead could be shut off
completely with blind rams.
3. In cases of emergency, the pipe string can be cut by cutting the drill pipe to seal
the wellhead completely.
4. After the well has been sealed, such special operations as mud circulation,
choking, killing and well washing can be performed through pipe manifold for well
killing and choking connected to spool and side outlet of BOP.
5. When used together with the choke and kill manifold, it can control the well
pressure effectively and achieve near-balance well killing operations.
2.1. Explanation of the Model of Ram Blowout Preventer
2.2. Technical Parameters of the Ram Blowout Preventer
3. Operating Principles
3.1. Principles of the Open and Closure of the Ram
When the high pressure oil of the hydraulic control system is introduced into the
left and right hydraulic cylinder ram closure chambers, the impelling piston drives
the ram shaft and the left and right ram assembly to the center of the wellhead
along the Ram Block chamber to close the well. When the high pressure oil is
introduced into the left and right hydraulic cylinder ram open chambers, the
impelling piston drives the ram shaft and the left and right ram assembly away from
the center of the wellhead to open the well. The open and closure of the ram is
controlled through the reversal valve of the hydraulic control unit. Generally the
open and closure operations can be completed within 3 to 15 second (but
correlated with the status of the hydraulic control system, the specifications of the
hydraulic control line and the length of this line).
3.2. Principles of Well Pressure Sealing
A ram blowout preventer can only effectively close a well when all the four seals
have taken effect. These four seals include the seal between the ram top seal and
the body, the seal between the ram front seal and the pipe, the seal between the
body and the bonnet, and the seal between the ram shaft and the bonnet.
The ram sealing process is divided into two steps. In the first step the hydraulic oil
forces the ram shaft to impel the Front Packer rubber element to make it deformed
and seal the front part and it also lets the Top Seal rubber element be interfered
and compressed to fill the gap between the Top Seal element and the body and
seal the top, thus finish the primary sealing. In the second step, with the help of the
pressure inside the well the ram is impelled from behind to allow the further
deformation of the Front Packer element and the ram is also impelled from the
bottom to let the body adhere tightly to the Top Seal element and thus achieve the
reliable sealing of the well. This is called the well pressure assisted sealing effect.
4. Structures and Features of the Main Components
4.1. Structural Features
Such major pressure bearing components as the body and the bonnet are cast
formed with alloy steels of high strength and high malleability and properly heat
treated. And the water pressure test for strength is performed for each preventer
according to the API Spec 16A standards before ex factory.
At the bottom of the chamber of the body and the ram there are high brace rods
and a sand depositing slop towards the well bore. So the sands and silts can be
removed automatically when the ram is opened and closed. This can reduce the
kinetic frictional resistance of the ram and is also helpful to the well pressure
assisted sealing of the ram. The inner surface of the ram chamber is smooth and
easy to clean.
A kind of floating ram sealing is adopted to reduce the resistance in opening or
closing the ram, minimize the wearing of the rubber elements and lengthen the
service life of the ram. It also prevents the body and ram from rusting together and
thus is easy to disassemble.
The retainers for the packing of the ram shaft are stainless steel and the slot for the
retainers is welded with stainless steel to improve the corrosion proof capability of
the blowout preventer.
The surface of the top seal of the chamber between the body and the ram of the
blowout preventer is chemically nickel plated to effectively improve its corrosion
resistance and its wear resistance.
The HF integral structure is adopted for this type of ram block. This allows the easy
assembling and disassembling of the sealing elements and the easy replacing and
repairing of the ram.
The NPT 1” female threads are adopted for the hydraulic connection threads on
the body. Oil tube sockets are installed outside and NPT 1” female threads are
processed on the oil tube sockets to protect the threads on the body. When the
NPT 1” female threads on the oil tube sockets are damaged the connection
threads on the body can be directly used.
The dimensions of the external connections are in conformity with the API Spec 6A norms.
4.2. Pipe Ram
There are 2 kinds of structures for the pipe rams. One structure is integral, the HF
rams and the other is the separated, the S rams. Both kinds of rams can be used.
The structure of S rams is old in style and the HF rams are recommended.
Table 8 Part List of the HF Ram Assembly
No. 1 2 3
Name Ram Assembly Top Seal Front Packer Ram Block
Quantity
Ram
Specification
1 1 1
C.S.O.
11153.02.09.00
11153.02.01.01
11153.02.09.02 11153.02.09.03
2 3/8" 11153.02.01.00 11153.02.01.02 11153.02.01.03
2 7/8" 11153.02.02.00 11153.02.02.02 11153.02.02.03
3 1/2" 11153.02.03.00 11153.02.03.02 11153.02.03.03
4" 11153.02.10.00 11153.02.10.02 11153.02.10.03
4 1/2" 11153.02.04.00 11153.02.04.02 11153.02.04.03
5" 11153.02.05.00 11153.02.05.02 11153.02.05.03
5 1/2" 11153.02.06.00 11153.02.06.02 11153.02.06.03
5 3/4" 11153.02.16.00 11153.02.16.02 11153.02.16.03
6 5/8″
11153.02.07.00 11153.02.07.02 11153.02.07.03
7" 11153.02.08.00 11153.02.08.02 11153.02.08.03
5-5 1/2" variable
diameter
11153.02.11.00 11153.02.11.02 11153.02.06.03
4.3. Ram Shaft Sealing Device
The bonnet and the ram shaft on the BOP adopt the both sides of sealing. The
sealing ring assembly, support ring and clamping ring are used to seal the well
pressure. The Y-ring assembly is used to seal the hydraulic pressure. (seeing the
figure11A, table 11 A)
The sealing element between the ram shaft and the bonnet is divided into two
parts, one for the sealing of the well pressure and one for the sealing of the oil
pressure of the hydraulic control system. The secondary sealing device is located
between these two parts. In general cases, the sealing at this part is very reliable
because of the multiple seal rings and the auxiliary sealing of the O ring in the
middle. However, in some cases the seal rings here are damaged because of long
terms of lacking of maintenance or other reasons. The leakages may be observed
when closing a well and in this case the secondary sealing device is then needed
to deal with this kind of emergencies.
If leaking liquid is observed from the inspection hole (below the bonnet) after a well
is closed, it indicates that a seal ring has been damaged. Which seal is failed
between well pressure side and oil pressure could be judged from the leaking
liquid. At this time loosen the plug screws of the grease injection hole at the top
immediately. And then loosen the screw bolts of the hole clockwise with a hexagon
ring spanner and inject the sealing grease into the annular space through the
check valve and the radial hole of the support seal sleeve to repair the sealing.
Precautions for the use of the secondary sealing device:
1. In order to prevent the secondary sealing grease from solidifying and becoming
invalid, the secondary sealing grease is not injected when the blowout preventer is
released from the factory. It is only provided as a kind of attachment to the
machine. It is also recommended not to inject the secondary sealing grease when
the blowout preventer is not used. It shall be injected just before the blowout
preventer is used in the well and it shall be taken out after the completion
inspection and the relevant parts shall be well cleaned.
2. The special tools shall be prepared at hand for cases of emergency.
3. The plug screw (with a small hole on it) of the inspection hole at the lower part of
the blowout preventer shall be inspected periodically to see whether there are any
leakages of well liquids or oil.
4. When a seal ring becomes faulty the amount of the secondary sealing grease
injected shall not be too much. The appropriate amount shall be the one when no
further leakages are observed at the inspection hole. The frictional resistance of
the secondary sealing grease is very large and it is attached with granular
substances. Thus it is rather harmful to the ram shaft when the ram shaft is in back
stroke.
5. After the secondary sealing is used the blowout preventer shall be examined
and repaired as soon as possible and the secondary sealing grease shall be
cleaned as soon as possible to prevent it from solidifying inside the grease
injection hole.
4.5. Locking Shaft Sealing Device
The ram manual locking device is composed of the locking shaft, the ram shaft and
the manual control assembly. For the manual locking device the hand wheel needs
to be rotated manually to enable the rotation of the locking screw and thus lock the
ram. It is used when the well needs to be sealed for a long period of time. It can
lock the ram at the closure position after the ram has been closed hydraulically.
And at this time the hydraulic pressure can be released. When performing the
locking operation manually after the ram has been closed hydraulically, rotate the
hand wheel to the right to enable the rotation of the locking screw through the
control lever. Because the end of the locking screw lies against the tail of the ram
shaft and cannot fall back, so it pushes the ram shaft toward the center of the
wellhead and locks the ram. The manual locking device can only be used to close
the ram. It cannot be used to open it. If you want to open a manually locked ram,
you must first reset and unlock it with the manual locking device and then open the
ram hydraulically. This is the only possible method. The specific operations include,
first rotate the hand wheel counter clockwise to the end, then rotate it to the right
for 1/8 to 1/4 circle to prevent the locking shaft from being locked at the unlocked
position because of the variations in temperature, and then open the ram
hydraulically.
4.6. Ram Manual Locking Device
The ram manual locking device is composed of the locking shaft, the ram shaft and
the manual control assembly. For the manual locking device the hand wheel needs
to be rotated manually to enable the rotation of the locking screw and thus lock the
ram. It is used when the well needs to be sealed for a long period of time. It can
lock the ram at the closure position after the ram has been closed hydraulically.
And at this time the hydraulic pressure can be released. When performing the
locking operation manually after the ram has been closed hydraulically, rotate the
hand wheel to the right to enable the rotation of the locking screw through the
control lever. Because the end of the locking screw lies against the tail of the ram
shaft and cannot fall back, so it pushes the ram shaft toward the center of the
wellhead and locks the ram. The manual locking device can only be used to close
the ram. It cannot be used to open it. If you want to open a manually locked ram,
you must first reset and unlock it with the manual locking device and then open the
ram hydraulically. This is the only possible method. The specific operations include,
first rotate the hand wheel counter clockwise to the end, then rotate it to the right
for 1/8 to 1/4 circles to prevent the locking shaft from being locked at the unlocked
position because of the variations in temperature, and then open the ram
hydraulically.
5. Product Spare Part List
5.1. List of Spare Parts
6. Installation, Uses and Precautions
Before installing the blowout preventer please make sure that you have read the
above chapters of this manual, where the structures, functions and operation
methods of each component of this blowout preventer are described in detail. Then
you can install and use this blowout preventer following the procedures described
below.
6.1 Installation at the Wellhead
6.1.1 The following checks shall be performed before installing this ram blowout
preventer:
(1) Check the integrity of the ring grooves of the flanges of the wellhead and the
blowout preventer and check that there are no protrusions on the surfaces of the
flanges.
(2) Check whether the specifications of the ram of the blowout preventer are
compatible with the dimensions of the drilling tools in the well.
(3) Check that it passed the pressure test.
6.2 Uses
A dedicated person should be appointed to be responsible for BOP and the
responsibilities should be defined clearly. The operator should have the knowledge
concerning working principles, performances and the process, and should be able
to operate, maintain, service and debug it also.
When testing the closure of the pipe ram, if there is not any pipe strings in the well
the maximum hydraulic control pressure shall not exceed 3MPa to avoid damaging
the rubber elements. When there is a pipe in the well it is strictly forbidden to close
the blind ram.
When it is needed to close a well for a long period of time, the ram shall be locked
with the manual locking device and a label shall be attached at the control console
indicating the actual situation to avoid any incorrect operations.
After entering the target layer, the ram shall be opened and closed once a day to
check whether it can be opened or closed smoothly and whether the manual
locking device is in good service. The open and closure of the blind ram shall also
be tested after each pulling out operation. It is strictly forbidden to close the blind
ram when there are some pipes inside the well.
6.2.1 Ram Sealing Test
The testing media shall be clean water or drilling fluid. During the pressure test the
timing shall be started after the pressure has been stabilized.
(1) Testing of the Blind Ram and the Pipe Ram
Testing Procedures:
A. Install the blowout preventer on the seat of the testing pile and connect the open
and closure pipe lines to the preventer. Connect the pipe lines from the high
pressure test pump to the seat of the testing pile or the side outlet of the blowout
preventer.
B. When testing the pipe ram, install the testing mandrel in the blowout preventer
and ensure that the mandrel is reliably connected to prevent it from breaking off
during the test. No mandrels are needed when testing the blind ram.
C. Close the ram hydraulically under a pressure of 8.4 to 10.5MPa (1,200psi to
1,500psi) with the hydraulic control handle at the closure position of the ram.
D. Improve the pressure inside the well to 1.4MPa to 2.1MPa (200psi to 300psi)
and keep for 10 minutes. Check if there are any leakages and the sealing is judged
as passed if there are no leakages.
F. Improve the well pressure to the maximum nominal working pressure of the
blowout preventer, 35MPa (5,000psi) and keep for 10 minutes. Check if there are
any leakages again and the sealing is judged as passed if there are no leakages.
G. Reduce the well pressure to zero.
For a variable diameter ram, its maximum sealing drill pipe and its minimum drill
pipe shall be tested separately following the same testing procedures described
above. For a variable diameter ram it is not allowed to close the well through
manual closure operations and the well can only be closed hydraulically.
(2) Testing of the Locking Device:
A. Close the ram hydraulically under a pressure of 8.4 to 10.5MPa (1,200psi to
1,500psi).
B. Rotate the locking shaft manually clockwise to lock the ram.
C. Reduce the hydraulic control pressure to zero and leave the hydraulic control
handle at the ram closure position.
D. Improve the pressure inside the well to 1.4MPa to 2.1MPa (200psi to 300psi)
and keep for 10 minutes. Check if there are any leakages and the sealing is judged
as passed if there are no leakages.
E. Improve the well pressure to the maximum nominal working pressure of the
blowout preventer, 35MPa (5,000psi) and keep for 10 minutes. Check if there are
any leakages again and the sealing is judged as passed if there are no leakages.
F. Reduce the well pressure to zero, rotate the locking shaft counter clockwise to
unlock it. After unlocking rotate it backward for 1/8 to 1/4 circles.
G. Open the ram hydraulically.
6.2.3 Testing of the Hydraulic Control System
The nominal working pressure of the hydraulic control system of the blowout
preventer is 21MPa (3,000psi). The open and closure of it shall be tested
separately when it is tested. The testing media is the hydraulic oil.
A. Without rams or bonnets are open. Pay attention not to let the ram shaft touch
the body when it is protruded. The blowout preventer shall be fixed to the ground to
prevent it from falling because of the shift in the center of gravity after the two
bonnets have been opened at the same time.
B. Perform the testing of the closure chamber under a pressure of 21MPa
(3,000psi) and keep for 10 minutes. Check if there are any leakages and the
sealing is judged as passed if there are no leakages.
C. Reduce the hydraulic control pressure to zero.
D. Perform the testing of the open chamber under a pressure of 21MPa (3,000psi)
and keep for 10 minutes. Check if there are any leakages and the sealing is judged
as passed if there are no leakages.
E. Reduce the hydraulic control pressure to zero.
6.3 Precautions
It is not allowed to release the pressure by opening the ram to avoid damaging
the rubber elements. Check whether the manual locking device has been unlocked
every time before opening the ram. After opening the ram check whether the ram
has been fully opened (drawn back completely inside the body) to avoid damaging
the ram by the drilling tools.
Name: Steven
Mobile：+8615369805074
Whatsapp：+8613512492572
Email：sales@fengliangpetroleum.com
Add：Binhai New Area, Tianjin City