In 2023, Géotec Group set up the Exploration department to extend its range of skills and provide a comprehensive response to its customers' requirements relating to studies of underground and hydraulic geotechnical structures, as well as those involving major geological challenges.
The department is involved in all phases of projects requiring in-depth or specific investigations, including sample testing and specific in-situ measurements: tunnels, deep storage structures, resources (mines and quarries), dams, foundations, water resources, hydraulic structures, etc.
Missions of the Exploration branch
The teams advise and support customers at all stages of design and execution of investigation projects, offering geological exploration engineering, with expertise in surveys, deferred logging, structural analysis, 3D geological modelling, geohydraulic testing, mechanical testing, instrumentation, sampling, etc.
In order to meet the technical objectives and optimise costs and deadlines, Groupe Géotec takes on the role of general contractor and as such is the main operator in charge of the programme of investigations, responsible for its coordination and general management.
Deep surveys and special surveys
Deep surveys correspond to geological, hydrogeological and geotechnical exploratory boreholes of up to 1,000 metres of wireline coring, subject to specific in-situ tests and measurements:
- Wireline core drilling at depths of up to 1000 m.
- Wireline core drilling at depths of up to 500 m using helicopter-borne equipment.
- Inclined or horizontal wireline core drilling at depths of up to 700 m.
- Destructive drilling at depths of up to 400 m.
- Gallery surveys by electric equipment.
In-situ testing and survey instrumentation
The Exploration business offers technical and financial optimisation for geological and hydrogeological exploration drilling thanks to significant engineering experience and a range of customised in-situ tests and measurements:
- In-situ mechanical tests: dilatometer tests, creep tests, hydraulic fracturing tests, 20 Mpa pressuremeter tests.
- Geohydraulic tests with obturators: Lugeon tests, Drill Stem Test (DST tests: pulse and slug testing).
- Groundwater testing: long-term pumping tests, fluid circulation tests using pygmy current meters.
- Survey equipment and instrumentation: extensometers, automatic inclinometers, seismometers, inverted pendulums.
- Sampling and laboratory tests: identification and mechanical tests on soil, rock and concrete.
Wireline Logging
By creating the Exploration department, Géotec Group is bringing logging in-house with experts who have the appropriate equipment at their disposal. Wireline Logging is the recording of geophysical parameters in boreholes. It is complementary to other geophysical investigation techniques and in-situ tests thus providing a tailored response for both routine geotechnical projects and specific projects at great depths.
Complementary expertise across the Group's businesses
- Borehole imaging (optical and ultrasonic televiewer) combined with structural analysis;
- Measurement of natural radioactivity (Gamma-Ray) for lithological reconnaissance and correlation between boreholes;
- Video inspection using a high-definition camera to characterise cavities;
- Measurement of the speed of P and S waves in formations (obtaining mechanical modules for formations).
- Locating water inlets and outlets of a structure and measuring their contribution in conjunction with pumping tests;
- Well inspection (video inspection, condition of well screens, verticality, etc.).
Maritime: Borehole Imaging and structural analyses related to the installation of infrastructure such as bridge piers or wind turbines.
Natural Hazards: Borehole imaging to determine and orientate structures and their apertures in order to identify a risk of instability.
Geothermal Energy: Identification of formations using gamma-ray measurements, cementation (CBL / VDL) and verticality control, and determination of the thermal gradient.
Material resources for the Exploration branch
Survey methods
Géotec Group has nine drilling rigs for a wide range of applications:
- 2 deep drill rigs: Puntel PX 1000 and Soilmec PSM16GT – 800 and 1300 m wireline coring capacities
- 1 Comacchio GEO 602EX drill rig – 600 m wireline coring capacity
- 1 Puntel PX800 drill rig on tracks – 400 m wireline coring capacity
- 1 Soilmec A980G drill rig on wheeled carrier – 400 m wireline coring capacity
- 1 Comacchio GEO 601 drill rig on tracks – 350 m capacity for wireline coring
- 1 CMF360 heli-portable halo drill rig on tracks – 300 m wireline coring capacity
- 1 ELI400 heli-portable halo drill rig – 500 m wireline coring capacity
- 1 Socomafor 140 drill rig on tracks – 200 m wireline coring capacity
Software
- WellCAD, Soil Cloud, GDM
- 3D software: SolRocks
- Various calculation software developed in-house
Deferred logging
- 2 measuring winches : 1 portable 150 mL unit, and 600 mL unit
- Gamma Ray probe (natural radioactivity)
- Optical and ultrasonic borehole televiewer (OPTV, BHTV)
- Acoustic caliper
- Full-Wave Sonic probe (P and S wave speed, CBL / VDL)
- Flowmeter with temperature and conductivity sensor
- 43 mm diameter HD video camera
- Magnetometric trajectometry measurement (azimuth, inclination, TVD, closer distance)
human resources
Géotec's Exploration department, comprising nine teams dedicated to deep drilling and three geological engineers, operates throughout mainland. The department draws on the Group's extensive range of human and material resources, optimising the efficiency and rapidity of operations.
In addition to the day-to-day partnership with teams in various businesses, the exploration department works in support of the Group's various subsidiaries, in particular C.S.I., the Italian subsidiary specialising in deep and complex surveys, with which they collaborate on numerous international projects.
Contact : contact.exploration@geotec.fr
