The method taking gas from a layer close to the surface is a well known method and was used for many years. In the past the purpose of use was the exploration of hydrocarbons but in the present time the importance of pollution control came more and more in the picture. This influence made the surface gas measurement as a very useful method which provides easily a good picture of an area being polluted by any kind of hydrocarbons like oil, gasoline or gas.
The exploration of natural hydrocarbons and the exploration of hydrocarbons being distributed by accidents or other undesired happenings are principle the same and based on the same physical and geochemical characteristics. The hydrocarbons are existing in both cases as liquids (higher hydrocarbons) or as gases (lighter hydrocarbons). In any way they are producing gases which can be captured and measured.
Hydrocarbons produce gases in any layer and these gases have the feature of migration from their point of origin up to the surface of the soil. Even covering layers which are very tight are bypassed and the gases are appearing at any point which is not vertical above the point of origin but anywhere at the surface.
Out of this phenomenon and the chemical and physical properties of liquids and gases the surface gas measurement became an easy and cheap method for the modern requirements of pollution control and detection of polluted areas and soil. Especially for old drilling sites it is a good and useful method to detect leaky casings and production probes as well as locations being polluted by mud and/or diesel oil.
Another application of surface gas measurements are the control of underground storage locations for hydrocarbons. In this case it is advisable to make a first measurement prior to the filling of the deposit and another one after filling. In regular time intervals more measurements are recommended or fixed probes could be kept in the soil and only from time to time new gas samples should be taken for analysis.
In the end the original reason for developing the surface gas measurements - which is the receiving of additional exploration information - exists at all times and brings new thoughts to an old instrument.
Surface gas measurements bring the following possibilities at low cost:
Low cost ! Fast result !
No influence to environment while measuring.
