Geothermal wells need to undergo a test program before they are used. This is so that the baseline conditions of both the wells and the geothermal aquifers that they tap can be determined. This baseline data are critical because all future information is compared against them.
After drilling has been completed and before the initial discharge, the well downhole conditions are measured. The temperature and pressure are measured by using a clockwork Kuster gauge or electronic logging tools. Standard practice is to initially do an injection (or completion) test, that is, sometime at a series of flows, where the temperature, pressure, and possibly flows using a spinner tool are measured at intervals down the open hole section of the well. (more…)
The total installed geothermal power generating capacity in the world is approximately 9000 MWe from 21 countries, with the United States leading at nearly 3000 MWe and The Philippines with nearly 2000 MWe (Table II). Other major countries are Italy, Mexico, Indonesia, Japan, and New Zealand, with between 400 and 800 MWe each. (more…)
Geothermal drilling technology is adapted from the oil industry. Most of the geothermal wells are drilled with a rotary-type drilling rig. Because of the hard, abrasive, and high-temperature volcanic rocks of geothermal systems, the drilling bits require hard abrasive resistant teeth such as diamond or tungsten carbide. Hence, geothermal drilling is an expensive activity in geothermal development. Most geothermal wells are drilled 1 to 2 km deep to intersect faults and fractures so as to increase the success rate of production from permeable zones. (more…)
Geothermal energy is energy created by the heat of the Earth. Under the Earth’s crust lies a layer of thick, hot rock with occasional pockets of water. This water sometimes seeps up to the surface in the form of hot springs. Even where the water does not travel naturally to the Earth’s surface, it is sometimes possible to reach it by drilling. This hot water can be used as a virtually free source of renewable energy, either directly as hot water, steam, or heat or as a means of generating power. Geothermal energy as renewable energy is nonpolluting, inexpensive, and in most cases the sources is renewable. (more…)
