Constructing the pumping test

We carry out pumping tests associated with the creation of our boreholes or not, (bearings, long duration, strong of a park of more 20 pumps, from 3 to 12 inches, for a capacity of 3 to 520m³ / h, moreover, one kilometer flexible or rigid pipe, 6 electromagnetic pulse flowmeters with continuously recording the flow and turbulence, a multitude of pressure sensors, physio-chemical measuring devices in situ performance (temperature, pH, potential conductivity d oxidation-reduction, iron, manganese, nitrate, hardness of water …).

Finally, our hydrogeologists are able to set up, follow and interpret the test pumping necessary to understand the aquifers and the structures that hold them.

In situ diagnosis

We need to check the quality of the frame of your collection, in regular control or in case of loss of productivity. We have two mobile workshops, energy free, for visual inspections, physio-chemical logs, micromoles, gamma-ray, diametric, cementation control … Up to a depth of 500 m you, will know everything about your well !
These investigations makes it possible to check the conformity of the structure, to detect possible anomalies (drilling of the casing, presence of deposits, and nature of the clogging …) and to identify the cause of a decreased flow.
Decennial control with at least a televised inspection of the work is an obligation in France :

• for public water (By order of 11 September 2003 reglementation). A control of cementation is necessary for asset capturing deep aquifer
• for geothermal small importance assets by 25/06/2015 reglementation

Instructions

• In situ intervention
• Data Acquisition: original information, treatments already carried out on the borehole, groundwater collected
• Verification of information and compliance with legislation
• Delivery of the full report
Duration: on average one day (depending on the depth of the boreholes and the output of the pump)
This operation generally requires the pump to be removed.

Visual Inspection

All drilling is subject to corrosion and clogging. A visual inspection makes it possible to see the drilling and to detect any anomalies, like
• checking its condition: corrosion, perforation, collapse, silting, clogging
• detecting the nature of corrosion
• detecting the type of clogging: mineral, biological to know how to treat it

Logging

Logging is a visual inspection to check the integrity of the equipment and detect any anomalies. It us to:
• measure and record the physical or physio-chemical quantities in a borehole, depending on the depth: Redox potential measurement, Ph,
• identify different water inlets inside the borehole by interpreting the conductivity temperature contrasts
• control cementing with CBL Cement Bound Logging, logging and joining the cement tube
• check the diameter to check the sections of the borehole all the way up
• Control the argilosity: determine if the clogging is related to the presence of clay: gamma rays

Maintenance and regeneration

The drilling work and collection processes are subjected to heavy pumping and contact with the natural environment and age more or less rapidly. Regular maintenance work can slow down this process and extend the life of the structures.

To do this we offer:

• The regeneration / rehabilitation of a water well or well by mechanical treatment (brushing, jetting, shock wave-hydropuls® process, airlift,) and / or chemical (acidification, disinfection)
• Setting up the testing pump (development, well, water table) to determine the new hydraulic behavior of the rehabilitated structure
• A live feed of the work in progress via visually aided inspection.
• And if need other services (draft, refurbishment of wellheads and frame).
The hydrodynamic characterization of the structure makes it possible to access the degree of clogging of a borehole. It is required to know the flow and the drawdown given by the drilling to see the decline. The test pumping determines how well the structure will work and what characteristics will be recovered.

How to use a test pumping prior to a maintenance operation

• carry out pumping tests to observe drawdowns, changes in groundwater conditions and pressure drops
• determine what the structure has lost in characteristics by comparing the different successive tests

To maintain your installation, two types of regenerations are possible:

Mechanical regeneration

• Limitation of the use of chemicals: more safety for staff and more respect for the environment
• No water neutralization
• Reduction of repair time

It works by brushing to drop deposits and swabbing to remove what clogs the porosity of the ground.

In addition, in certain cases, SONDALP uses its innovative Hydropuls® method: it allows a deep treatment of the aquifer at the periphery of the structure. The principle is to generate hydraulic shock waves by the sudden and repeated expansion of a highly compressed inert gases. This causes disintegration of fine grain fractions, mineral deposits, etc., contained in the openings of the strainer and the porosity of the filter bed and the aquifer reservoir.

Chemical regeneration

For certain pathologies, it is necessary to go for a chemical regeneration, in case of
• Mineral clogging: carbonates, iron oxides, manganese involving dissolution with an acid
• Bacterial problems: involving rinsing with a chlorine solution

Manual

• Diagnostic
• Proposal for a cleaning protocol
• Cleaning
• Report of the repair work

Rehabilitation and refilling

In case of structural disorder, we can carry out a rehabilitation by rechecking of all or part of the solid or screened tube, according to the pre-established diagnosis.

In case of permanent abandonment of the structure, the regulation requires that refilling is adhered by the rules of the trade, that is to say by reconstituting the naturally impermeable zones in cement grout, and by filling the aquifer zones with an inert porous formation (sands, gravels).

We abandon a borehole if:
• The borehole is old, with too much damage to be repaired
• The ground reservoirs are polluted
• The commune is fed with water differently and no longer uses the borehole

Instructions of use

• File prior to filling / Diagnosis to make file prior to filling
• Re-sealing according to the filling conditions of the decree of September 11, 2003

Maintenance program

The average age of a drill is 40 to 50 years old. In many cases, no fund is budgeted to maintain the drilling. Curative maintenance is expensive and sometimes involves blocking production.

Preventive maintenance anticipates these problems and:
• follow the work in real time
• anticipate the cleaning of boreholes so that it is simpler and shorter
• prevent the stoppage of production
• avoid heavy investments in case of substantial work by smoothing reconditioning prices over the duration of the subscription

SONDALP offers a maintenance program: you entrust us with your drilling, we upgrade it and we give it to you with the same performance 10 years later.

The benefits of the maintenance program

• Peace of mind
• Improvement and maintenance and optimum performance:
– Guarantee in water production and capacity
– Maintaining a constant water quality

• One source of liability: transfer of operating risk to SONDALP
– Warranty on pumping equipment
– Prolongation of the life of the asset
– Improved knowledge of well condition

• Financial forecast :
– Fixed annual fee
– Reducing pumping costs by improving energy efficiency