shut_in_procedures

Shut in Procedures n

Shut in methods: – Hard Shut in. – Soft Shut in.

n

Shut in procedure while drilling.

n

Shut in procedure while tripping.

n

Diverter procedures.

Shut in Procedures At the end of this section you should be able to: n n n

Describe well shut-in methods. Describe shut-in procedures during drilling and tripping operations. Describe diverter procedures during drilling and tripping operations.

Shut in Procedures The shut in procedures are implemented once a kick is suspected. These procedures vary depending on whether the BOPs are surface or subsea type, and whether the kick occurs while drilling or tripping. There are two types of shut-in methods in the oil industry: n

Hard shut-in.

n

Soft shut-in.

The use of the Hard Shut-in method is implemented in IPM in order to minimized the size of the influx and provide lower choke and annulus pressures.

Hard Shut-in In the Hard Shut-in method, the choke and the valve immediately upstream of the choke on the choke manifold are to be kept in the closed position. The remote operated choke line valve (HCR) on surface BOPs or the failsafe valves on subsea BOPs are to be kept closed. Choke Closed

To Mud gas Separator, Mud tanks, flare or overboard Kill line Valve Closed

Choke line HCR Valve Closed Bleed--off line to flare or Bleed overboard Drill string

To Mud gas Separator, Mud tanks, flare or overboard Choke Closed

Soft Shut-in In the Soft Shut-in method, In the soft shut-in method, the HCR valve is closed and the choke is open during normal operations. Choke Open

To Mud gas Separator, Mud tanks, flare or overboard Kill line Valve Closed Bleed--off line to flare or Bleed

Opened Choke Line HCR Valve

overboard To Mud gas Separator,

Drill string

Mud tanks, flare or overboard

Choke Closed

Shut in Procedures while Drilling 1. 2.

Stop rotation. Raise string to shut in position (time permitting).

3.

Stop the pumps and check for flow; if well flows, proceed without delay to the next step.

4.

Close annular preventer and open remote controlled choke line valve (HCR).

5.

Sound alarm and notify PIC.

6.

If the well has been closed using the annular preventer, check space out (pipe rams vs. tool joint relative position) and close pipe rams and ram locks.

7.

Bleed off pressure between pipe rams and annular preventer (if possible).

8.

Record casing and drill pipe pressures and pit gain.

Shut in Procedures while Tripping 1.

Set slips below top tool joint (no tool joint next to blind / shear rams).

2.

Install full opening safety valve and close same.

3.

Close annular preventer and open remote controlled choke line valve (HCR).

4.

Sound alarm and notify PIC.

5.

Make up kelly or top drive (insert a pup joint or single between safety valve and top drive) and open safety valve.

6.

Record casing and drill pipe pressures and pit gain.

Diverter Procedures The diverter system is not an element of the well control equipment, it is not intended to shut-in or halt well flow. The diverter system, provides a lowpressure flow control system to direct controlled or uncontrolled wellbore fluids away from the immediate drilling area for the safety of personnel and equipment, while drilling surface hole (prior to setting the surface casing on which the BOP stack and choke manifold will be installed). During diverting operations, fluid flow will continue until the hole bridges, the reservoir has depleted or hydrostatic pressure can be built enough to regain primary control and stop formation fluid flow.

Diverter Procedures while Drilling 1.

Stop rotation. Do not stop pumping.

2.

Open diverter vent line to divert / close diverter.

3.

Increase pump strokes to maximum.

4.

Switch suction on mud pumps to kill mud in the reserve pit. Zero stroke counter.

5.

Raise the alarm. Evacuate all non-essential personnel immediately.

6.

Post personnel to look for gas appearing at the waterline if not already in place (jack-up, swamp barges).

7.

If the well appears to have stopped flowing after the kill mud has been displaced, stop pumps and observe the well.

8.

If the well appears to continue to flow after the kill mud has been pumped, switch to the active system. When all mud has been consumed, pumps to water. Do not stop pumping for as long as the well continues to flow.

Diverter Procedures while Tripping 1.

Set slips.

2.

Open diverter vent line, close diverter.

3.

Stab safety valve and close same.

4.

Make up kelly or top drive if possible.

5.

Open safety valve and start pumping at maximum pump speed.

6.

Switch suction on mud pumps to kill mud in the reserve pit. Zero stroke counter.

7.

Raise the alarm. Evacuate all non-essential personnel immediately.

8.

If the well is not flowing after displace the kill mud, stop pumping. Observe the well.

9.

Prepare to run back to bottom.

10. If the well appears to continue to flow after the kill mud has been pumped, switch to

the active system. When all mud has been consumed, pumps to water. Do not stop pumping for as long as the well continues to flow.