How to Prevent Drilling Fluids from Contaminating Core Samples

来源: | 作者:selina | 发布时间 :2024-12-18 | 30 次浏览: | Share:

How to Prevent Drilling Fluids from Contaminating Core Samples

In geological drilling, one of the critical challenges during exploration coring drill rig operations is preventing the contamination of core samples by drilling fluids. Contaminated samples can lead to incorrect data interpretation, which may impact critical decisions during mineral exploration or geological surveys. Here’s how to prevent such contamination effectively:

1. Use the Right Drilling Techniques

Choosing the correct drilling method is the foundation for maintaining clean core samples. The portable full-hydraulic core drilling rig is an ideal option because of its precision and low risk of contamination.

Low-pressure Techniques: Avoid using excessive pressures during drilling. High-pressure drilling increases fluid penetration into the rock core.
Controlled Rotation Speed: Optimizing the rig's rotation speed reduces the abrasive effect of fluids.

2. Select the Proper Drilling Fluids

The choice of drilling fluid plays a pivotal role in reducing contamination. Some strategies include:

Non-Invasive Fluids: Use fluids with lower viscosities that minimize the chance of adhering to the core.
Environmentally Friendly Fluids: These are easier to clean off cores and are less likely to alter their chemical composition.
Filtered Fluids: Ensure drilling fluids are free of unwanted particles.

With a Rig for geological surveys, operators can integrate more advanced filtration systems to manage drilling fluids effectively.

3. Deploy Core Barriers and Isolators

To protect core samples, employ specialized tools that limit fluid exposure:

Core Catchers: Installed inside the core barrel, they help isolate the core from drilling fluid during extraction.
Double/Triple Tube Barrels: These tubes prevent fluids from directly touching the core, maintaining its integrity.

Using advanced tools alongside a High-pressure drilling machine ensures the sample remains uncontaminated.

4. Optimize Drilling Pressure

While high pressures are sometimes necessary, they can drive fluids deep into rock formations. To minimize this:

Adjust drilling pressure to match the geological conditions.
Monitor the pressure through the rig's control systems.
Use pressure-reducing valves when operating high-pressure rigs.

5. Core Cleaning and Preservation

After extraction, cleaning the core is critical to removing residual fluids:

Washing: Use water or low-impact cleaning solutions to remove surface contamination.
Preservation: Store the core samples in sealed containers to prevent additional contamination.