The Requirements for Core Drilling for Coal

Core drilling consists of a large truck that has a boom attached to the rear where workers add long sections of pipe together. The first metal shaft or pole that starts to drill down into the earth's dirt has a bit that cuts through the dirt. Once that section of pipe is close to the end the workers will add additional sections of pipe down to the required depth that a core sample will be extracted.

The whole process of core drilling requires a constant flow of water to the drill so that the bit can cut through the earth's dirt. Without the water, the drill will become hot and get caught or twisted on the rock below. Once a core driller reaches the required depth of the drilling then the workers will start taking off sections of the pipes and layout the core which will be in each section. A core sample is just a circle the size of the shaft that has cut down into the earth's dirt. When unloading the core out of the rods it requires great care in making sure the core sample is laid out in boxes and marked according the depth of the core sample.

Core drilling is a critical process when searching for coal and determining the height of the coal reserves below the earth's dirt. When core drilling for coal and emptying the rods workers must use great care because the drilling of the coal usually will not capture any coal samples because the water that is flowing through the drill will just cut right through the coal seam. However, when determining the coal seams height you can measure the distance between the last core sample to where it starts again. This measurement of a probable coal seam in a mountain is enough to determine if there's a potential for mineable coal.

Opening a coal mines is very expensive and getting a good core sample is critical in determining if it's feasible to try to extract the coal. Coal companies spend a lot of money for core drillers to drill for a potential coal seam. Core drillers can get anywhere from $10-$20 for each foot drilled and the average depth for a core driller is anywhere from 700-900 feet. So that equals a lot of money for a potential core drilling. Core drilling equipment is very expensive along with the fuel and water that is used during a drilling.

Core drillers when setting up their drill will try to find a stream located close by to feed water to the drill truck this is more economical versus trying to haul in large amounts of water. If a core driller can find a steady stream of water to run back to their drill they can save a lot of time and money. When running a core drill the person drilling into the earth must monitor the rods and make sure that the drill head is turning. Too much pressure on the drill can bend the rods and burn up the drill head leading to more costly repairs.

Source:
www.westvirginiacoalmining.com