Prashant Modi – Development methods for coal production

Prashant Modi - coalDevelopment methods by Prashant Modi

According to Prashant Modi, in the development of any coal bed methane field, the key elements which must be considered are the thickness and permeability of the coal, and the gas content. A relatively large number of pilot well are usually required before the productivity levels of the reservoir (that is, the recoverable reserves of methane) can be predicted for the average well and for the field in its entirety.

The process of developing the coal bed methane field has to be done in accordance with a carefully considered plan, so as to maximise the profitability, gas production and field life. Firstly, Prashant Modi says that the reservoir’s geology, including the inter-bed formation has to be studied in great detail, so that the degree of fracturing, coal thickness and lateral extent of the reserves can be determined. Using this information, the reservoir’s approximate volume can then be calculated. As the field is developed, the temperature and gas content of the reservoir must be estimated; this is because coal bed methane fields are developed using core analysis programs, including pressure cores.

Another important aspect of this developmental stage is accurate, consistent testing of the wells. This data is then digitally stored, where it can be used to map out the methane reservoir, with these maps being updated as each additional well is drilled. Once these maps have been created, coal bed methane fields are then divided up into individual reservoir compartments, based on the variations in permeability, coal bed thickness or faults. More mapping is then conducted to get a better understanding of the characteristics of each of these sub-divisions of the original reservoir. These sub-divisions will often differ not only in permeability, but also in water and pressure levels.

Some coal bed methane extraction companies will use regional statigraphic studies to understand the unconformities, sequence boundaries and sedimentary differences in each sub-division- this information, Prashant Modi says, can be useful for predicting oxidized zones and coal cut-outs. Thermal modelling is another method of examining the reservoirs; this tells the company about the formation pressure, gas content, coal maturity and burial history.

CBM drainage systems – what are the benefits? An explanation featuring Prashant Modi

Coal bed methane drainage systems have become increasingly popular with energy companies over the last few years. Aside from the cheaper costs associated with the shallow coals beds, Prashant Modi, an expert in the subject, says that this type of system offers a number of advantages in terms of finance and efficiency. Here we go through these benefits in more detail.

English: Road end sign, Letham Moss Composite ...

Prashant Modi – Road end sign, Letham Moss Composite Energy are extracting coal bed methane from flooded coal seams beneath Letham. (Photo credit: Wikipedia)

One of the most appealing aspects of the coal bed methane drainage system for most natural gas companies is the savings which can be made in ventilation power costs. Coal bed methane drainage systems do not require the installation of additional ventilation methods for production, which can save the energy company a significant amount of money over time. Prashant Modi says that this reduction in ventilation costs also leads on to further savings, as there is less need for development openings. This means that the number and size of shafts which connect the coal seam to the external surface can be cut down on, resulting in far cheaper production costs.

Coal bed methane drainage systems also result in an increased reserve –with less development openings such as head-gates, sub-mains and mains, a larger quantity of methane from the coal can then be extracted from blocks of a fixed size. This is because only about half of the methane inside coal which is located in the development sections of the mine can be extracted, whilst more than 85% of the methane located in the production sections of a mine is suitable for extraction.

Yet another benefit of coal bed methane drainage systems, according to Prashant Modi, is that there are fewer delays associated with the production process as a result of excess water. The presence of large volumes of water in the roof strata of a coal mine is often cited as the reason for costly delays occurring with underground mining work, particularly in relation to the development sections inside the mine. According to Prashant Modi, these delays can be mitigated, and in some cases completely eliminated, by the use of a coal bed methane drainage system.