The general guidelines for drilling given below should be followed along with hole specific requirements:
- The ID of all downhole equipment shall be checked for free passage of a free point indicator tool and survey instrument fishing tools.
- Jars shall be run when required.
- Consideration shall be given to running a junk sub in conditioning assemblies that are run prior to a PDC drill bits or corehead assembly run. However junk subs shall not be run in a poor hole conditions which may require extensive reaming. Junk subs may fail when subjected to full drilling parameters.
- The hole shall be adequately cleaned at all times.
- Flow checks shall be performed on the following occasions:
– All significant drilling breaks.
– Prior to a trip out of the hole.
– At the casing shoe.
– Whenever the Driller is in doubt with respect to control of the well.
– Gas show and bubbling.
- Slow Circulation Rates (SCRs) shall be performed.
During the drilling phase slow circulation pump pressures shall be taken during each shift, or after changes are made which would affect the pumping pressures. The results shall be recorded at the Drillers position and daily in the IADC report.
- A diverter system shall be installed on the conductor casing when drilling:
– All exploration and appraisal wells with a jackup rig.
– The first well on a production platform (platform rigs) or jacket.
– All consecutive wells on a platform/jacket, if shallow gas is evident.
- If, after drilling out the shoe, the formation strength test indicates that insufficient formation strength exists to safely perform a killing operation using a conventional technique, then consideration shall be given to drilling the next section with a diverter installed.