Exploratory drilling is the process of performing test drilling to find the physical properties and boundaries of a reservoir or deposit of a given material. Exploration drilling companies provide this service to mining companies to find deposits of minerals or other materials that they seek to exploit.
Exploration drilling is the first step taken and must show successful results before development drilling can take place. It is essential for determining temperature levels, retrieving rock samples and fluid samples to perform chemical analysis on them.
While geophysical methods can provide useful information about the subsurface structure to determine the best locations for drilling, exploratory drilling is necessary to obtain actual temperature and fluid measurements and samples.
Following are the various types of exploratory drilling techniques available: exploratory wells, core holes, slim holes and thermal gradient holes. These methods are used initially because they are far less expensive than drilling a full sized production well in a random location.