Gas reserves

One of the major indicators of development or industrialization of any nation is the level of her per capita commercial energy use. The three most important commercial energy used in present world are natural gas, oil and coal. Natural gas is Bangladesh's only significant source of commercial energy, with 2002 production of 384.9 billion cubic feet (bcf). Bangladeshi natural gas production began in 1960 from the Chattak field. There is much uncertainty and debate about the level of natural gas reserves in Bangladesh. Estimates from Petrobangla put net proven reserves at 15.3 tcf as of mid-2004. The US Geological Survey has estimated that Bangladesh contains an additional 32.1 tcf in additional "undiscovered reserves.
Why is this uncertainty and debate? The answers are that, problem in selecting reserves estimation method, lack of sincerity and lack of honesty. There are four methods for gas reserves estimation. These are- Material Balance Method, Volumetric Method, Decline Curve Analysis, Reservoir Simulation. But in Bangladesh only material balance method and volumetric methods are used and accurate assessment is not possible. So
I think to get the real picture about gas reserves, the other two methods i.e. decline curve analysis and reservoir simulation should also be used if economically feasible.