ADP Group crews are proficient and skilled in the provision of rotary drilling techniques, and can deploy various methods via modern, multi-purpose rotary rigs to achieve good core recovery and accurate results, in any geological formation.
Boreholes can be drilled with a combination of dynamic sampling and rotary coring; rotary casing or hollow stem augers are used to progress through any geology encountered. At any stage within a borehole, both undisturbed sampling and geotechnical testing can be carried out.
Boreholes can be progressed via dynamic sampling and rotary coring, to depths in the order of 200m. Wireline coring can be used as an alternative to conventional coring, aiding efficiency at greater depths, providing good core recovery in softer formations and class 1 samples.
Both air and water flushing mediums can be utilised to assist borehole progression. ADP Group crews are experienced in the investigation of potentially contaminated sites, and can implement measures to accommodate both yellow and red category sites.
Dual casing systems can be installed to provide environmental seals in heavily contaminated soils.
Dynamic Sampling
Quality, bulk-disturbed samples of unconsolidated, superficial stratum.
Samples are presented in rigid plastic liners, in sizes ranging from 86mm to 146mm. Samples are taken with a hydraulic-percussive sample hammer, mounted adjacent to the rotary head on ADP Group’s multi-purpose rotary rigs. This percussive hammer in-turn drives a 1.5m sample barrel through the superficial stratum, to collect samples in rigid, plastic liners.
Rotary casing or hollow stem augers are then used to over-drill the dynamic sampling barrel, allowing retrieval to the surface for presentation to the engineer.
Rotary Coring
100% core recovery in changeable, competent geology.
Conventional rotary coring, utilises a triple barrel coring system (double barrel system, plus a rigid plastic liner) to obtain continuous samples through competent stratum. The driller has a selection of core bits available to him, to allow progression through a complete spectrum of geological formations; the rig has various settings (speed, feed/weight) to ensure recovery is optimum.
Conventional coring can be carried out with water, air or mist flush, as a medium to clear the bit, lubricate and cool.
Wireline Coring
100% core recovery in changeable, competent geology, with no time lost tripping drilling rods in and out on every run! Speed and quality, rolled in to one efficient system; Geobor-S.
Like conventional rotary coring, wireline coring utilises a triple barrel coring system (double barrel system, plus a rigid plastic liner) to obtain continuous samples through competent stratum.
The driller has a selection of core bits available to him, to allow progression through a complete spectrum of geological formations; the rig has various settings (speed, feed/weight) to ensure recovery is optimum. Where wireline coring differs from conventional, is that there is no requirement to trip the rods in and out on every run.
The Geobor-S rods are effectively a casing, they hold the coring barrel in a locking mechanism within the lead length, this barrel is then retrieved via an over-shot mechanism, attached to a high-speed wireline winch, mounted alongside the standard rig service winch. The barrel is retrieved to the surface, liner exchanged (core removed), and launched back in to the string,
to commence the next run.
Core barrel exchanges takes c.1-2mins dependent on depth, this system is up to 500% quicker than conventional coring, in deeper boreholes.
Wireline coring can be carried out with water, air or mist flush, as a medium to clear the bit, lubricate and cool.
Undisturbed Sampling
Class 1, undisturbed samples can be taken with thin walled sample barrels, samples are then waxed to protect the moisture content, and sent away for the relevant lab-tests.
U70 – 70mm undisturbed sample barrel system, complete with a retrievable steel liner.
U100 – 100mm undisturbed sample barrel system, complete with a retrievable steel liner.
U100T – 100mm undisturbed sample system, thin walled, class 1 sample.
Single barrel liner.
Geotechnical Testing
Standard Penetration Testing
SPT – Standard Penetration Testing, weight of 63.5kgs is dropped over a calibrated distance of 760mm, the number of blows taken to drive the sampler over a set distance is recorded. All SPT hammers are calibrated annually.
ADP Group utilise a mixture of rig mounted, and ancillary trip hammers operated by the winch.