Drilling is involved in the process of mineral exploration where the subsurface is defined. Through it, the details for the final assessment of a prospect is generated, which will also eventually determine if the location is mineable or not. In addition, samples of the geochemical analyses from the drill are provided, which will serve as the basis for determining the average rating of the ore deposit. Logging the drill samples carefully helps define the numbers and calculate the volume of ore as well as provides significant structural information. Below, we will discuss an overview of diamond drilling. We’ll also tackle the two guiding principles of drilling.
Diamond Core Drilling
This is a process of mining diamonds, with its main component being a diamond bit. The diamond bit punches through a solid column of rock, creating a motion that will change its current state upwards into the drill pipe and will be recovered above.
The standard coring bit and drilling sizes vary in specifications, depending primarily on the intended applications. As for the drill rods, their length is typically 10 feet. After the 10-ft rod is driven through the ground, the next step is screwing another section of pipe into its top end, thus, the combined network can be drilled 10 feet further into the area.
There are two ways to conduct D core drilling: conventional and wireline. Their main difference is the process of recovering the core sample when you finally have a full inner tube. In conventional drilling, you must remove the entire drill string from the hole and you must take apart the threads and rejoin them for each core sample every end of the cycle. As for the wireline core drilling, a piece of equipment called overshot is placed down the drilled hole to do the releasing and recovering of the inner tube.
The two are then transported up to the surface using a wireline pulley, letting the rods and core bit stay in the hole. Moreover, the wireline method is the more common method today because it is efficient and safe.
The core drilling process consists of three major operations including, the actual ground drilling, the core sample retrieval, and lastly, the replacement of the equipment. While the drilling is happening, fluids that are called “drilling fluids” are then poured down into the drill string. These fluids act as a cooling agent for the bit and additionally make bringing the drill cuttings back up to the surface easier. Moreover, as the drill bit begins to wear out, it can no longer cut properly. Hence, the application of drilling fluids or replacement of drill bits is necessary to lessen delays and downtime.
The Core Sample
The ultimate goal of the drilling process is reaching the core to acquire a sample. This being said, there are ways or products that can make the core recovery much easier and faster, aside from the application of drilling fluids.
Once the sample is recovered, it is stored in a core box after each drilling cycle. In addition, all important information about the core sample should always be logged or recorded in the form of a document. Such information is vital for geologists, helping them pinpoint mineral deposits and determine whether the numbers are big enough for mining.
While professionals involved in drilling and ore mining are already familiar with the information discussed above, it’s essential to review the fundamentals in order to keep your knowledge fresh. For novices in the field of diamond drilling, it’s best to continue reading a variety of resources and consult experts when you encounter elaborate questions.