Case study: Timor Sea

PROD proves to be the ideal tool for the site conditions at a Timor Sea geotechnical investigation

The Project

Location: Timor Sea, Australia
Date: June 2006 – July 2006
Vessel: Mermaid Investigator
Geology: Loose to Medium Dense silty fine carbonate SAND with thin layers of weakly cemented Calcilucite
Description: 15 boring locations in water depths of approximately 100m producing 174.4m of coring and CPT information

Overview

Benthic Geotech recently completed a safe and successful drilling, sampling and insitu testing programme at a Timor Sea field. The project was completed with zero equipment down-time. Benthic Geotech provided the full services for the investigation including the provision of the vessel (Mermaid Investigator), hydrographic surveying (via Tri-Surv), onshore laboratory testing and engineering interpretation of the test data to provide design soil parameters.

The investigation provided geotechnical data for the confirmation of acceptability of FPSO drag anchors at the site and also provided data for a site specific assessment for the use of a jack-up drilling rig at this field.

Significant achievements at Puffin Field using PROD

PROD provided a number of extra benefits to the client. These included:

  • Detailed and accurate characterisation of near-surface hard soil layers. PROD's ability to switch between CPT and piston sampling and drilling through hard layers when these are encountered were essential to gaining an understanding of the site.

  • This ability allowed the client to modify the soil boring programme as the understanding of the site increased with each borehole.

Excellent productivity was achieved. The 15 Investigative boreholes were carried out with CPT testing at each location delivering 123.5m of 18-bit CPT data. Sampling at the borehole locations, using the unique combination of controlled piston sampling and the newly designed Benthic Geotech core catcher, resulted in 25.5m of sand samples being obtained. All site operations were completed in 4.2 days total operating time.