Borehole Services - Think Water

Drilling Of Boreholes In Zimbabwe or South Africa: For many people, drilling is only the activity above the ground that they can see and observe. 

A water borehole is, however, a specially engineered hole in the ground, making provision for the water to flow into this hole and allowing for a pump to be installed inside the hole to allow abstraction of water. Part of this engineered design is to prevent the surrounding geological formations to collapse and closing the borehole. 

This could mean cost and energy to re-drill or clean the hole to be able to use it again.

The task of the driller is to drill and construct a borehole, not to get water. This task should be left to the scientist dealing with the nature and study of the geological formations. None can, however, operate in isolation and it important to see the actions of the scientist and driller as a team effort.

There are very few people that take time to consider how the drillers manage to keep a vertical borehole, which went through sand and hard rock, open until the casing is installed. How does one manage to remove the drilled pieces of rock from deep below the surface? Skill is needed to guide and control a water well drill as it penetrates sand, gravel, clay and solid rock formations underground. The drill rods are quite heavy and can weigh several tons; if the drill pushes too hard or turns too fast, the drill bit will wear out too fast; if it does not push hard enough, it won’t penetrate.

Quite often several rock layers are encountered in a single borehole, each requiring different drilling pressures and speeds. When water is encountered the drilling becomes even more complicated and the driller needs to understand exactly what forces need to deal with to further penetrate.

Two methods are typically used in South Africa for the drilling of water boreholes, these being the (mud) rotary and air percussion methods. A third method the cable tool method used to be quite popular, but due to the time it takes to drill a hole with this technique it is not quite as popular anymore. There are other methods, and combinations of methods, but these are the most common. Most home wells are drilled to 6 or 8 inches in diameter. Municipal or irrigation wells are likely to be drilled at larger diameters, sometimes as much as 24 inches or more.

1. The (Mud) Rotary Technique: In rotary drilling, a drill bit is attached to a length of connected drill pipe. The drill bit will be made of tough metals such as tungsten, and as the drill is rotated the bit grind up the rock. The drill fluids (sometimes referred to as drilling mud) are circulated through the drill string into the borehole and back to the surface and carries (flush) the broken pieces (cuttings) upwards and out of the hole. 

Borehole Services - Think Water

This fluid also serves as a formation stabilizer preventing possible cave-in of unstable sands or crumbly rock before the good casing or well screen is installed. Furthermore, this fluid acts as drill bit lubricant. As the drill intersects water-bearing rock formations water will flow into the hole. Drillers or geohydrologists on-site will carefully monitor the depth of water “strikes” and keep a note of the formations in which they occur.

2. Air Percussion Technique: This technique utilizes compressed air to operate a down-hole air hammer on the end of the drill string that helps to break up the rock formation. This technique is currently the most commonly used technique in Southern Africa and many successful boreholes have been drilled applying this technique. 

The compressed air that is used to operate the down-hole air hammer also blows the crushed rock fragments out of the hole to the surface along with any water that flows into the hole during drilling. This has many times lead to the belief that this is of course not (** always) true as it is the compressed air that forces the water out of the borehole and not necessarily the relief of water pressure that allows water to freely flow on the surface.

Artesian wells do exist where after completion of drilling, water carry on flowing on the surfaces specific application.

Costs: The cost of a borehole can be significantly influenced by the applied design as well as the difficulty to construct a borehole in a specific geological formation. Many times people try to save on costs and therefore they will budget for the drilling of a borehole, but not for the casing of a complete hole. Installation of the casing, which might in the short term seem costly, will almost always pay off in the long run. This casing will allow for the borehole to stay open for years after completion, and correctly installed it will also assist in keeping the borehole clean and free of material that could damage your borehole pump.

For All Your Borehole Drilling Services Contact Us:

Five Facts About Borehole Drilling That You Need To Take Note Of:
1. Know Your Borehole Casings:The Preferred Borehole Casing In Zimbabwe Is Class 9 and 10 (Pressure Classes.)This is because Class 9 and Class 10 Casings are more collapse resistant. The strength of a Casing is often described as collapse resistance.

2. Borehole Drilling Depth: The exact depth, of where the water is located, cannot be established by the drilling contractor nor the Water Surveyor (Borehole Siter).

3. The Is No 100% Guarantee On Water: It is important to note that it is never a 100% guarantee that any hole will yield water, the amount and water quality can also not be guaranteed by the drilling contractor and water surveyor.

4. Borehole Siting or Water Surveying Is Important: Making use of a hydrologist or traditional water diviner will increase your chances of having a successful borehole that will yield a sufficient amount of water.

5. Know The Risks: The risk of the borehole drilling lies with the property owner. The client will still be liable for the drilling costs irrespective of a borehole yielding water or not.

The Cost or Prices For Borehole Drilling in Zimbabwe:

1. Siting: $100.00USD
2. Drilling and Casing: (40 Metres) $1300.00USD - (Using Class 6)
3. AC Electrical Installation: $1000.00USD
4. Solar Pump Installation: $1400.00USD
5. Extra Metres After 40 Metres: USD $45.00USD per metre.
6. 5000 Litre Tank and 4 metre Tank Stand: $1000.00USD
7. Stuck Pump Fishing Out: $180.00USD
8. Capacity Testing: $250.00USD

- Casing with Class 9 Casing incurs an additional $200.00USD.
- Double Casing: $20.00USD per metre.

Note this is the average price borehole companies charge for their services in Zimbabwe, but this figure is subject to changes if conditions are different depending on the construction site.

Request A Quote:

If you have further questions, contact our friendly team today they will be more than happy to assist.

Phone: +263 719 187878
Chat via WhatsApp:

Your Link To The Best Borehole Drilling Companies in Zimbabwe!

Think Water Zimbabwe is an Franchise Group made up of Locally Owned and Operated Borehole Drilling and Water Systems Businesses located throughout Zimbabwe.

We specialise in delivering Innovative and Sustainable Irrigation, Pumping, Filtration and Water Solutions. Think Water Zimbabwe provides a comprehensive range of Borehole Drilling, Intallation and Water Systems Related Services including System Design, Product Supply, Installation and Ongoing Maintenance.

Our Services and Solutions are scalable to suit Urban and Rural Residents, Commercial and Industrial Businesses in Zimbabwe.

Think Water Sales Online
Think Water Zimbabwe Is Your One-Stop Shop For All Borehole Drilling, Irrigation, Solar Powered Pumping and Water Management Needs in Zimbabwe. Think Water Zimbabwe
Connect via WhatsApp