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Drilling & Well Services Training
1.11.1 Diverters-KFDJ
Operating parameters is typically 750 psi closing pressure through 1-inch ID lines with a maximum wellbore pressure of 500 psi. Closing time is less than 10 seconds. Overboard lines should be as straight as possible in configuration to minimise erosion during diverting. Diverters can be connected directly to the conductor or drive-pipe or attached above the BOPs. On floating rigs the diverter is used to prevent trapped gas from reaching the rig floor after a kill operation.
Outer Packer
Flowline/Vent Outlets
Rotary Table
Test Tool
Handling Tool
Outer Packer
Flowline/Vent Outlets
Diverter Assembly
Fill-up Line
Test Tool
Figure 32 - KFDJ Diverter
Diverter Assembly
Insert Packer
Fill-up Line
Figure 32 - KFDJ Diverter
□ rillinq S Well Services Trai n in g
On manually operated systems the proper sequence for diverting is as follows:
• Open overboard line valve down wind of the rig; close shaker line valve and then close diverter.
Automated systems combine the actions listed above in one simultaneous function. With these systems the appropriate (downwind) vent valve should be selected prior to diverting.
In the past diverters have failed due to control system faults, human error, eroded and ruptured vent lines and blocked or plugged vent line valves. An important consideration is the proper maintenance and testing of the diverter system at regular intervals. Vent lines should be flushed and vent line valves should be function tested to ensure proper operation.
Open Close
Diverter Packer
Open Close
Overboard Vent
PORT SIDE
Flowline to Shale Shaker
Diverter Packer
Open Close
Overboard Vent
Open Close
Flowline Seals
Energise Vent
Energise Vent
Open Close
Full Opening Valve w/Hydraulic Operator
Overshot Packer
Flowline Seals
Energise Vent
Open Close verboard Vent
Open Close
STARBOARD SIDE
Energise Vent
Overshot Packer
Figure 33 - KFDJ Hydraulic Functions
Diverter Hook-Ups - KFDJ
Drive Pipe Hook-Up
Conductor Pipe Hook-Up
Optional Conductor Pipe Hook-Up
Surface Pipe Hook-Up
Figure 34 - Typical Drilling Operation Sequence
1.11.3 Diverters - MSP
- Piston Indicator
Packing Unit
Opening Chamber Head
Latching Mechanism
Opening Chamber Piston
Closing Chamber
Figure 35 - Hydril MSP Diverter
Packing Unit
Opening Chamber Head
Latching Mechanism
Opening Chamber Piston
Closing Chamber
Figure 35 - Hydril MSP Diverter
1.11.4 Hydril MSP 29 Y2" 500 psi Diverter
The MSP 500 permits open hole to be drilled full bore with diverter protection. It also permits the setting of large sized surface casing without removing the diverter. Thus the diverter is always ready for venting gas flows. The new design employs fewer parts and weighs less while at the same time decreasing the risk of malfunction. When using the MSP as a diverter during top-hole drilling, the primary purpose is to divert well flows away from the rig and personnel. This application avoids shutting in the well, but instead permits routing of the flow to a safe distance on the down wind side of the rig. Seal off is affected by hydraulic pressure applied to the closing chamber, which raises the piston unit radially inward into a sealing engagement. The MSP 500 however, is not well pressure assisted. If valves are to be added to the vent lines it is recommended they be full opening and designed to automatically open when the diverter is closed. This can be accomplished by using the closing pressure of the diverter as the pilot pressure for the valve, i.e., as closing pressure is applied to the diverter that same pressure causes the valve to open, thus assuring that there is no large well bore back-pressure build up.
Flow Line
Hydraulic Power Fluid Supply
Close Open i
Flow Line
Bell Nipple
Figure 36 — MSP Diverter Functions
Bell Nipple
Full Opening Valve (Automatically Opens Before Diverter is Closed)
Drive or
Conductor Pipe
Drilling Spool
Figure 36 — MSP Diverter Functions
1.11.5 Diverters
A diverter is a safety system, which reroutes a well fluid flow away from the rig. Shallow gas is permitted to flow until depleted, or until the well is bridged over or killed by pumping in heavy mud. Ready during upper hole operations, a diverter is intended for use when there is a danger of penetrating a pressurised gas zone, while the casing shoe strength may not be sufficient to contain shut in pressures. Massive flows of gas and sand can quickly destroy a rig's diverter system. Hydril incorporate integral valve functions and switchable target to minimise equipment and thereby decrease the risk of malfunction. Upward motion of one component, the piston, stops upward flow of the well fluid and opens the vent line. All that is required is one hydraulic signal from the remote panel, and since there is no waiting on valve functions a fast response is ensured.
Figure 37 - Surface Rig Diverting fo M k
Figure 37 - Surface Rig Diverting
Hydril diverter with integral valve functions and switchable target
Shale shaker
Starboard vent
Always open flow selector
Port vent
Starboard vent
Always open flow selector
Port vent
Shale shaker
Sequential diverter system
Shale shaker
Starboard vent
Port vent
Flow target
Port vent
Flow target
Valve function:
- Diverter valve
- Flowline valve
- Block valve
- Port vent valve
- Starboard vent vdve
Starboard vent
Figure 38 - Integral vs. Sequential Diverter Systems
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