Well Control during Logging Operations

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Wireline BOPs are not normally used for open hole logging operations or cased hole operations where the Drilling BOPs are installed.  Exceptions to this rule are:

  • Open Hole logging operations (rig on site) where losses or kicks have been encountered during drilling. The Drilling Supervisor and Drilling Engineer shall decide if a 7in shooting nipple and large wireline BOP is required. The logging contractor shall be advised in such cases  as the equipment is not normally carried to the rig for regular open hole logging.
  • Cement Bond logging with pressure applied to casing. This pressure (generally 1000 psi) is applied when there are doubts about the cement quality with the normal bond log.  It helps to differentiate between cases of micro-annulus and channelling. A 7in shooting nipple and large wireline BOPs are required.
  • Perforating overbalanced in fields where pressure regime is well known. A 7in shooting nipple and large wireline BOPs are required
  • Perforating underbalanced or perforating overbalanced where the pressure regime is not well known requires full pressure control equipment.

Note:    In normal circumstances full pressure control equipment operations are performed on the (fine) monocable, with equipment of reduced diameter to pass through completion strings.  Operations with large multi-conductor cable are not recommended where the pressure exceeds 1000 psi as the upthrust on the cable becomes significant above these pressures (greater than 2 000 lbs).

1. Shooting nipple/Wireline BOPs not Installed

Tool String in Hole

If the well is in a stable condition, logging tools are run without wireline BOP / shooting nipple installed.  After a long logging session the possibility exists, that the hole starts flowing slowly.  Proceed as follows:

1. Stop logging and perform flow check.

2. If the well is flowing, Close in the well using annular and strip tools out of hole. Shear the cable using blind/shear rams if needed but do not cut logging tool.

3. Monitor the pressure build up.

4. Kill the well by stripping volumetric or bull heading method.

Toolstring out of Hole

If the well flows whilst the toolstring is out of hole, close in the well with the blind/shear rams.

Kill the well as per “well control procedure while out of the hole”.

2. Shooting nipple / Wireline BOPs Installed

Toolstring in Hole

If the well starts flowing with the logging tool in the hole, the following action shall be taken:

1. Close wireline BOP

2. Monitor pressure build up.

3. Kill well through rig BOP kill-line (volumetric kill or bull heading)

Toolstring out of hole

When the well flows with no tool in hole:

1. Close the blind/shear rams

2. Monitor pressure build up

3. Volumetric kill the well or bullhead the influx back into the formation

Note: Depending on pressures, stripping operations may be considered.

Comments  

#1 Boubenia 2014-06-19 10:40
hi, we need 100 shooting niplle; where we will find them.
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