05.07.2009

Geopressurized zones are natural underground formations that are under unusually high pressure for their depth. These areas are formed by layers of clay that are deposited and compacted very quickly on top of more porous, absorbent material such as sand or silt. Water and natural gas that is present in this clay is squeezed out by the rapid compression of the clay, and enters the more porous sand or silt deposits. This natural gas, due to the compression of the clay, is deposited in this sand or silt under very high pressure (hence the term ‘geopressure’). In addition to having these properties, geopressurized zones are typically located at great depths, usually 10,000-25,000 feet below the surface of the earth. The combination of all of these factors makes the extraction of natural gas in geopressurized zones quite complicated. However, of all of the unconventional sources of natural gas, geopressurized zones are estimated to hold the greatest amount of gas.

Large-scale geological structures that might hold oil or gas reservoirs are invariably located beneath non-productive rocks, and in addition this is often below the sea. Geophysical methods can penetrate them to produce a picture of the pattern of the hidden rocks. Relatively inexpensive gravity and geomagnetic surveys can identify potentially oil-bearing sedimentary basins, but costly seismic surveys are essential to discover oil and gas bearing structures

Russia has the world’s largest proven reserves of natural gas, followed by Iran and Qatar. Qatar is the world’s largest supplier of LNG. Other major gas exporters include Algeria (8th largest reserves in the world), Brunei, Indonesia, Malaysia, Norway, Nigeria, Oman, Australia and Turkmenistan. At the end of 2006 global natural gas reserves were as follows (in trillion cubic meters): Middle East (73.4), Europe and Eurasia (64.13), Asia Pacific (14.82), Africa (14.18), North America (7.98), South & Central America (6.88).

A person who studies the history and development of the earth’s crust

A device used in seismic acquisition that detects ground velocity produced by seismic waves and transforms the motion in electrical impulses

Global demand for LNG, led by the United States, China and India, is forecast to raise from 226 bcm in 2007 to 640 bcm by 2020 and close to 790 bcm by 2030 on the back of economic growth and environmental concerns

GII is a company that specializes in geophysical exploration and research for oil and gas industry, water resources development, environmental studies, geophysical engineering and earthquake seismology, both in Israel and abroad