Near shore barge drilling and sampling with Legion Drilling

Some of the most interesting and exciting drilling programs are completed from barges along Australia’s east coast lakes, rivers and harbours. These investigations cross all disciplines from Geotechnical boreholes to environmental sediment sampling of te sea floor for contaminates. Sonic drilling from barges is becoming increasing popular with their ability to handle both unconsolidated and rock formations. Legion Drilling has sonic rigs available fitted with diamond coring heads which allows sampling of both sediments and rock effectively with a single machine.

Managing the logistics around drilling from barges is a big challenge and finding the right sized barge for the best drilling rigs is a struggle. Generally speaking you are looking for a small drilling rig to complete this kind of drill program given the costs and scarcity of barges.

Often the weight capacity, draught and anchoring mechanism of the available barge will dictate size of rig that can be put on the project. The unique operations considerations of an overwater drilling project include the impacts of tides, water depth, public and commercial boat traffic, access to amenities and importantly environmental management considerations.

It is not uncommon for delays in re-positioning barges due to weather. Most barges are towed into position and this can be dangerous in rough conditions.

The barge needs to be set up with a “moon pool” where the rig can drill through the floor of the barge whilst allowing enough room to run out rod racks, water tanks, waste storage and consumables required for instrument installations such as monitoring wells, inclinometers, vibrating wire piezometers or tilt-meters.

Preferred tidal cycles can occur at inconvenient times of the day or night and some tidal influences occur only a few times each year. On occasion it may be required to shut down boat traffic in the area to minimise the impact on small floating barges. Jack up barges provide much more stability but are not always suitable in shallow tidal areas.

At Legion Drilling we have a range of Environmental, Geotechnical and Sonic suitable for drilling from barges. Our small Geoprobe rigs have powerful hydraulic rams that make them perfect for conducting Cone Penetration Testing (CPTu) and other in-situ tests such as dilatometer (DMT), shear vane and piston sampling.