Wednesday 28 July 2021


We have the following services:

- Water Borehole
- Supply and assembly of electric pump
- Holes for foundations
- Piezometer holes and staking
- Geothermal boreholes
- Biogas boreholes
- Drilling
- Cleaning and recovery of boreholes
- Non directed horizontal drilling
- Water Flow tests
- Reports
- Technical assistance

Drill and water Boreholes

António Valente - Sondagens Lda, is at your disposal to do all types of work of drilling and foundations, for water research. We make the necessary studies (geological, hydrogeological, water flow tests) in order to guarantee the best quality and quantity of water.

With the adequate equipment and a team of professional technicians, with experience in this type of work, ready to help you, we make a service of reference in the market.

A groundwater Borehole correctly designed and sized should ensure the following points:
- Extraction of the intended flow rate without causing modification in the aquifer;
- Quality water;
- Protect the aquifer of local water sources from contamination.

Our company sends the responsible for the technical area to the intended location and we make a preliminary estimate about the depth the hole should reach and the flow rate that can be expected. This preliminary study is extremely important because it gives the costumer an estimate which allows him to make an evaluation of the cost/benefit ratio of his investment in a hole.

Drilling methods

Our company uses two methods of drilling: Rotary by direct circulation and Rotary Percussion – Hole bottom hammer. The selection of the method depends on the purpose of the depth and the geological formations to drill.

- Rotary by direct circulation:
The Rotary method consists on crushing and wearing the lithological formations reducing them to small particles through the use of a circulatory trepan. The movement of this part is accompanied by the circulation of “muds” constituted by bentonite and water. The function of these “muds” is to remove and bring the drilling debris to the surface, avoid the collapse of the walls because of the drilling, lubricate and cool the crushed parts.

This type of drilling is used and very advantageous when the geological formations are not consolidated. Our company does this type of drilling with direct circulation, as shown in the following picture:

Rotary by direct circulation click to enlarge

- Rotary Percussion:
This method is based on the crushing and cutting of the layers by a drill driven by compressed air. This compressed air is produced from a compressor which is transmitted through the inside of the drill string.

We use this method only for consolidated formations and hard rocks and, because of the speed of drilling, the cost is lower than through the rotary method. Besides, using this method it is possible throughout the course of the work, to have an approximate idea of the various aquifers units that are going through.

Rotary Percussion click to enlarge

Electric pumps assembly

The electric pumps includes the submersible pump, control equipments and accessories. The choice of the electric pump meets the flow test specifications done at the end of the hole.

Final report

Our company makes the final report of the works where there are all the details of the work done, in compliance with the no 3 from the article 41 from the Decree-Law no 226A/2007.

Water Drilling (Vídeo)

Water Drilling (Vídeo)

Head office
Rua Escola 14, Assafora
2705-464 São João das Lampas - Sintra

Phone 219 612 336
Mobile 964 044 202

Branch office
Zona Industrial da Sertã
6100-711 Sertã

Phone 274 601 811
Mobile 966 915 960

Online contact form