398 PFD Test

Owned by Chieh Peng (Unlicensed)
Last updated: Feb 08, 2023
2 min read

Chieh Peng, Johanna Suhonen, Oscar Cavazos

New type of tracer CH5278 ((PFD) Perfluoro Decalin P/N 003283, 500 gm unit) was purchased due to difficulty of obtaining CH5029 ((PFMD) Perfluoro Methyldecalin P/N 003296-1Kg).

Test for lower pumping rate was performed during EXP398

  1. Manual pumping from both HPLC pumps were conducted to confirm that both pumps can pump at 0.1 ml/min as the lowest rate.
  2. The tracer pump was not functioning with RigWatch, We found the main cause was due to recent configuration changes to the serial server by developers. Those configuration changes were not reciprocated to the virtual serial port software running on Krakatoa, causing a communications issue with RigWatch and the tracer pump. After changing the virtual serial port configuration to match the serial server configuration, communications were restored.
  3. During U1596B, due to the above issue, tracer pump didn't start until the last 2 cores. Cylinder samples were taken form the last 2 cores, but no tracer was detected
  4. During U1600C, driller turned the pump on with 0.2 ratio while drilling down the hole. Drilling fluid was samples from the drill floor with very random results. Samples were taken either directly from outside of the core with a cylinder or IW scraping. Minimum and random peaks were detected from all samples. However, one water sample taken from inside coreliner shown 10ppb peak. We increased the pumping ration to 0.4 after core 5R. But no difference in any of the results.
  5. Ship mechanic performed routine maintenance on the mud pumps before U1599C
  6. During U1599C, we stared with pumping ratio of 0.4. First drilling fluid was sampled about one hour after pump was turned on. Over-saturated (>400ppb) result was detected. This was repeated in subsequent drilling fluid samples taken at hourly rate.

  7. 3 sediment samples were taken from the cores (all IW scraping), and the following results were found

    core

    ppb PFD

    26R3

    1.019

    27R4

    0.293

    28R2

    3.115

  8. We believe pumping ratio of 0.4 is sufficient to detect the new tracer PFD downhole. The inconsistent concentration can be speculated as the PFD does not mix well with seawater. 

  9. Further testing may be needed
  10. Data