The purpose of drilling can be divided into: geological drilling, hydrology, water well drilling, engineering exploration, drilling, oil drilling, and so on.
Drill hole is as follows:
1. from different geological drilling in deep drilling hole made at the core, samples were analyzed to identify the differential body or divided into strata, determine stratum geological conditions of the operation. Generally, the cost of drilling in geological prospecting should be at least 40%. Drilling diameter is small (46~91 mm), according to the different minerals, depth from tens of meters to several thousand meters.
2. water well drilling: drilling to aquifer (bit), cementing holes, so as to meet human and livestock drinking water problems and farmland irrigation, or provide hydrological observation for the geological department. General geological drilling, survey hole diameter of less than 150 mm, exploration hole diameter of 150~350 mm, well diameter 150~550 mm, hole depth of more than 300 meters.
3. geothermal drilling: drilling into geothermal resources for exploitation through thermal carriers. At present, the general technique of drilling depth can reach 3000 to 5000 meters, the better is the Yangbajing Geothermal field using high temperature geothermal resources, geothermal field in Xi'an, Beijing and Tianjin in the North central.
4. engineering investigation drilling: to obtain core and soil samples from drilling to analyze the physical properties, and to determine whether the foundation of the foundation meets the load, gravity and stability of the construction. Engineering geological drilling for the investigation of dam foundations, reservoirs, channels, port projects, high-rise buildings, and engineering geology along railways and highways.
5. oil drilling: drilling, drilling, direct resource development and utilization, the country's three well-known: PetroChina, Sinopec, sea oil. The drilling hole is 915 millimeters wide, the end hole is 216 millimeters, and the hole depth is 1000~7000 meters or more. The blowout preventer is usually installed at the wellhead.
6. cultural relics survey drilling (drilling): intuitive and accurate access to a certain place of cultural accumulation of information, it is less than excavation, labor-saving, destructive, in a short period of time to understand the larger area of the underground. Applicable to the specific understanding of site accumulation distribution, thickness, large construction sites, large tombs and ancient city shape and layout etc..