Gas Balance

Gas Balance

 

the quantity of gas being generated in a mine shaft and the distribution of gassing either by sources or throughout the system of workings. A distinction is made among the gas balances for individual workings, cutting sections, and shafts or for the mine as a whole. Knowledge of the gas balance is a basic prerequisite for selecting gassing control methods, shaft ventilation systems, and the methods of working the mineral.

One of the methods for determining the gas balance is the gas survey. The gas balance of a shaft is determined mainly by natural conditions and the mining-engineering factors of the working. The gas balance according to methane sources is composed of gassing from the coal seam or seams being worked, from adjacent gas-bearing coal seams; and from enclosing (surrounding) rock. Methane-rich shafts can be divided into two groups according to the makeup of the gas balance: the first group includes shafts working a single seam; the second, shafts working a series of seams. For the first group, gassing in the face area of more than 75 percent (less than 25 percent in the worked-out area) of the total methane discharge in the cutting section is typical during the cutting of a seam with small losses. The distinguishing feature of the second group is that the gassing in the face area is 50-60 percent and less (40-50 percent and more in the worked-out area) of the total methane discharge within the cutting field.

References in periodicals archive ?
Ali-Reza Kameli, head of National Iranian Gas Exports Company, said the last calendar year, which started on March 21, was the first year Iran witnessed a positive gas balance, the oil ministry website reported
Hatem Nuseibeh, president of Total UAE and member of the Gas Arabia Advisory Board added: "Total have been following the gas balance in this region for a while, and we can see that there is a need to prepare for the future, to make sure that there is the supply that is needed to satisfy the growing demand in the region.
Also, he said, according to gas balance by 2030 its production will increase to 60 billion cubic meters, with the exception of the volume of gas required to maintain manufacturing activity.
One of the direct consequences is the noticeable differences in gas balance results at month's-end closing.
Over the past two decades, Total said, LNG has emerged as increasingly core feature of the global gas balance, with growth of about 7% a year since 2000.
If TEPCO's plan is implemented as it is, it will have a serious impact on the greenhouse gas balance.
Topics include: greenhouse gas emissions from soils, land use change effects on soil carbon stocks in temperate regions, mountain soils in a changing climate, greenhouse gas balance in disturbed peat lands, and a summary of soil carbon in sensitive European ecosystems: from science to land management.
More important for Egypt's oil and gas balance of payments has been the lag in developing new gas production, owing to the delay in agreeing commercial terms with foreign oil companies for bringing on stream a number of new gasfields discovered in deep water off the Delta coast.
However, the EC gave itself until the end of 2010 to decide whether and to what extent to factor in ILUC, a phenomenon said to occur when crops are displaced by biofuel feedstocks to be cultivated elsewhere, causing new land to be brought into arable production and affecting the overall greenhouse gas balance.
The project's head, Petro Miroshnikov, has recently told Reuters the planned LNG terminal's capacity is equivalent to almost 20% of Ukraine's gas balance, representing a "serious diversification of our gas import system".
Today we are seeing some glut in the market, but I'm confident that in more than three years, we will see the gas balance again," Attiyah said.
Projects carried out in 2009 such as the Hasdrubal field or the "South Gas" project will help Tunisia achieve a surplus in the gas balance which will reach about 2 Mtoe in 2012 and might provide the opportunity for the country to sell this product in other markets.