How to drill a borehole in rocky areas in Nigeria

Drilling boreholes in rocky areas can be challenging because it requires specialized techniques.

However, there is no cause for alarm. This article will guide you on how to drill a borehole in rocky areas in Nigeria. Here are the techniques for drilling a borehole in rocky areas in Nigeria:

1. Site assessment and preparation

Before drilling a borehole in any area, you must first conduct a site assessment. It is the same for rocky areas. Before digging, ensure you conduct a geological and hydrogeological survey of the proposed borehole site.

2. Geological surveys

While carrying out a geological survey, you need to analyze the soil and rock samples to understand the subsurface conditions.

A geological survey ensures engineers drill the borehole in the best place and to the proper depth. This survey will reveal the depth and type of rock, groundwater levels, and potential challenges.

It also detects the presence of dangerous chemicals, poor water quality, and whether the geography of the area suits the requirements.

3. Hydrogeological survey

A hydrogeological survey examines the groundwater available in your area. The survey assesses the best location to determine whether there is enough water in the area.

The survey helps assess risks and challenges associated with drilling in that area. This risk assessment increases the chances of a successful drilling project, reduces the risk of contamination, and improves groundwater management.

4. Choose the correct drilling method

Drilling in rocky areas requires specialized techniques. Here are different types of drilling methods for rocky areas:

4.1 Air rotary drilling

Air rotary drilling is one of the most common methods for drilling through rocks. It involves the rapid rotation of a drill bit mounted at the end of the drill pipe. The force of the drill bit breaks the rock into small pieces. Drilling mud is then circulated to cool and remove the debris.

This method is effective for all rock types, including deep and hard rocks. It allows quick penetration and gives better control over the drilling process.

4.2 Percussion drilling

Percussion drilling is also known as cable tool drilling. This drilling method is a manual drilling technique.

A heavy hammering tool is attached to a cable and inserted into the borehole. The hammering tool is repeatedly used to hit the rock to break it. The cutting bit is attached to a cable and lowered into the open hole.

This method of drilling is inexpensive. However, it cannot break rugged rocks.

4.3 Diamond drilling

Diamond drilling uses a drill bit embedded with industrial diamonds to cut through extremely hard rock. This method has the major advantage of being precise and effective for breaking down very hard rocks.

Because it is precise, it significantly reduces damage to surrounding rocks. This method is the most expensive, but it assures a high-quality borehole.

5. Maintenance tips for boreholes in Nigeria

5.1 Ensure regular inspection

Check the borehole site regularly for signs of damage, leakage, or unusual changes in the surrounding environment.

Ensure you carry out occasional professional checks to assess the condition of the borehole, its components, and its surrounding infrastructure.

5.2 Test the water

Ensure you regularly test the quality of the water to check for contaminants like bacteria, heavy metals, and chemical pollutants. If the water is contaminated, treat it. To keep the water clean, ensure that the top of the borehole is properly sealed to prevent contamination from surface water.

You can also install a borehole filter to remove dirt and sediment before the water is pumped out. The filter consists of screens with small holes that allow water to pass through but trap larger particles.

5.3 Carry out routine checks and prompt repairs

To ensure operational efficiency, regularly inspect the borehole for any damage. Check for reduced flow rates, unusual noises, or vibrations.

Ensure you engage a qualified engineer to service the pump and address any mechanical issues. To maintain water quality, promptly address any damage to the borehole seal.

6. Cost of drilling a borehole in Nigeria

The cost of drilling a borehole in Nigeria varies based on several factors, such as location and terrain, drilling method, depth, and geological condition. For example, drilling a borehole in a rocky area will cost more than usual.

In some regions, the manual drilling process can cost as low as ₦150,000 to ₦300,000. At the same time, heavy-duty drilling can cost between ₦500,000 and ₦3,000,000, depending on the region.

7. Final words

Drilling a borehole in rocky areas of Nigeria requires expertise, specialized equipment, and techniques. Investing in a borehole will definitely provide you with a reliable water source. By understanding the techniques, maintenance methods, and cost implications, you can make informed decisions on your borehole project.

At Daibau, we have qualified engineers and experts to take on your borehole drilling project and help you make informed decisions.

If you are looking to drill a new borehole or repair an existing one, we are your best bet for both quality and affordability.

Click the link below to learn more.