Casing – a pipe cemented in the well to seal off formation fluids and to keep the hole from caving in. The spaces between the pipes and the well wall are filled with cement. The casing forms a major structural component of the wellbore and prevents the fracturing liquid from penetrating into surface waters.
Geophone - a device that detects ground velocity produced by seismic waves and transforms the motion into electrical impulses.
~ Natural gas
Natural gas - is a type of organic fossil fuel. A naturally occurring mixture of hydrocarbon and non-hydrocarbon gases in porous formations beneath the Earth’s surface. It is a naturally occurring light hydrocarbon gas mixture consisting of methane in 90%, ethanol and a pair of high-order hydrocarbons. It is used as an energy source to heat buildings, generate electricity and to produce fuel and methanol.
Types of natural gas are:
• conventional gas
• unconventional gas
~ Coalbed methane CBM
Coalbed methane CBM - natural gas consisting of nearly 100% methane, located in underground carbon deposits. Methane particles on the molecular level are attached to carbon and are released in a process called desorption.
~ Unconventional gas
Unconventional gas - natural gas resources which require greater than industry-standard levels of technology or investment to harvest. The most common types of unconventional gas resources are:
• shale gas
• tight gas
• coalbed methane CBM
• deep gas
• gas hydrates
~ Shale gas
Shale gas - natural gas, commonly referred to as shale gas, obtained from shale rocks, characterized by a high content of organic matter and low values of porosity and permeability. Shale gas is found trapped in small spaces between rock layers. The volume of every space is several times smaller than with conventional resources. Shale gas is not different from natural gas - it contains methane (75 - 95%) and nitrogen as well as ethane, propane, helium, oxygen and carbon monoxide. It is odourless.
~ Deep Gas
Deep gas (gas found at depths with extreme orogen pressure greater than the average for a particular area) - spaces with extreme orogen pressure are underground rock formations created by clay layers, affected by higher than normal pressure at a given level. Water and natural gas which occur in clay are squashed by the sudden compression of clay and pushed into sand or mud under high pressure. Spaces with extreme orogen pressure occur mostly on low levels (3 to 7.5 km underground) which makes extraction even more difficult.
~ Drilling platform
Drilling platform - a construction of several tens of metres high used for drill work. Its components are: a drilling rig, lifts, pumps and containers.
~ Methane hydrates
Methane hydrates - frozen gas with water. The water particles create a cellular structure in which the gas molecules are trapped. Methane hydrates are found in the shallow lithosphere (to 2000 m deep) Proper forming conditions are in sedimentary rocks located in polar areas (surface temperature below 0 degrees Celsius) or in oceanic sedimentary rocks above 300 m underwater (water temperature approximately 2 degrees Celsius).
~ Drill site
Drill site - terrain surrounding the drill. The drill area is specially designed to perform any drill work.
Concession - a grant extended by the Polish Ministry of Environment to permit a company to explore for and produce oil, gas or mineral resources within a strictly defined geographic area. Concession granting is regulated by the "Geological and Mining" Act. There are two types of concessions: exploration concession and extraction concession.
Borehole - completed drilling opening, performed in the rock mass for research, exploration, documentation or production purposes reinforced with a head allowing extraction of the mineral. The borehole is cemented and fully sealed. Ensuring full tightness of the borehole is a technological condition for the process of hydrocarbon production. There are vertical and horizontal drillings.