Pretest pressure sampling while drilling -FPWD-
At certain stage of drilling and at the zone of interest, the drilling stops and hole cleaning process takes place to have a safe sampling operation. A full structured procedure will be done to have formation pressure reading by deploying a probe that seal the borehole and suck the fluid at various speed. Date is collected recorded in memory and sent to the surface.
As QA/QC checks we need to pay attention to those points.
- The down hole gauges calibration.
- The probe sealing status and type.
- The battery life time.
- The tool vacuum.
- Deck tests and results.
- The rat hole to allow the probe reaching the zone of interest.
- The pipes stretch.
- Drilling hazard and well control condition (stationary time allowed)
- The mud type.
- Nearby production status SIMOP.
- Depth control system.
- Log gaps and relogging.
SWD sampling while drilling using MPSRs.
The SWD is almost have same precautions as the FPWD, but as a tool the most expensive LWD tool and it’s more complicated to operate due that it’s offering the possibility to get fluid samples in the bottles (called MPSR)
Additional precautions are:
- Number of bottles vs number of sampling client request.
- Shipment procedure.
- Site opening sampling bottle (if required).
- Fluid down hole analysis.
- Pipe deck working area.
- Latest framework version for DH and surface software.