Gas influx inhibits oil-mining

Use our resources wisely. Photo: Philatron.com

MYANMAR'S drilling for oil in the disputed water-zone of the Bay of Bengal has probably been accelerated by similar activities by Bangladesh in the Chittagong area during the recent past. Both Myanmar and Bangladesh have vast deposits of natural gas that can meet their industrial and domestic energy needs for quite a long time. Both can be benefited if drilling for oil is deferred till exhaustion of the gas resources to a desired level. Simultaneous drilling by the two countries in the border areas has resulted in the recent political crisis.
It was only in late 2007 that the issue of exporting gas to India was included in our national agenda. It didn't take even a year to declare that gas deposits in Bangladesh were exhausted, and if gas was not imported from Myanmar, functioning of the gas-based industries, including the power plants in Bangladesh, would be jeopardised, and household use of natural gas would have to be stopped!
It's not difficult to draw the following conclusions:

• Both Bangladesh and Myanmar have a surplus deposit of natural gas
• Our politicians and bureaucrats are not aware of the real situation of the gas and oil resources and are allowing the multinational companies to drill for oil; or
• Geopolitical pressures from outside are turning the waters of the Bay a bit turbid!

Spokespersons of the caretaker government also stated that no agreements would be signed that might go against the legitimate right of Bangladesh over its energy resources.
The activities in the Bay did not escape the notice of a few concerned individuals like Prof. Anu Muhammad, Oli Ahad, Kamal Lohani, and Dr. Anwar Hossain, who tried to draw public attention to the issue.
Lately, a Channel I coverage showed representatives of all leading political parties speaking out against any agreements with foreign energy companies on exploration and production of oil and other mineral resources in the country.
It's the right time to warn the present and the future governments to take every step with care because mineral resources, once exhausted, may not accumulate within the next thousand years
Natural gas and oil, called "hydrocarbons," are basically the same, and can serve the same purposes. Wherever there is natural gas, there must also be oil in the lower stratum, provided some geological conditions prevail to allow accumulation. Because gas is lighter than oil, it floats in the upper stratum.
The topography of Bangladesh extends from the hilly north to the plains in the south. The vast gas deposit in the upland of Comilla, Sylhet and Chittagong extends to the low-lying coastal area, where the oil is deposited in the semi-porous rocky beds of coral islands.
Co-existence of gas and oil in the coastal area was confirmed about 40 years back, but oil-mining activities did not start partly because of some technical reasons and partly for the geopolitical pressure of the multinational oil companies.
Geopolitics is the influence of the donor countries on dependent nations in exploring and utilising their mineral resources. The history of oil-production in Nigeria and Venezuela is a burning example of this geopolitics. Venezuela recently stopped foreign interference in its oil exploration and production.
While natural gas co-exists with oil, it also creates a serious problem called "influx" in the output of oil. To reduce this disturbance of gas in oil-mining, specially-designed wells are suggested, where a barrier for the natural gas is built so that it cannot reach the actual point of oil-pumping. Quotes from an article by Dutch specialists A.P. Leemhuis, S.P.C Belfroid, and G.J.N. Alberts clearly describe these technical phenomena thus:
"Gas to Oil Ratio (GOR) constraints can severely limit oil production and reservoir drive energy [...] optimisation [of oil production] can be achieved by controlling the location and amount of gas influx in a horizontal smart well [...] the gas phase may start to dominate production, which will deem the well to be uneconomical [...] the influx of gas may damage topside equipment [...] the gas-cap of the oil reservoir will be depleted fast, taking away its drive energy [...] the most common way to prevent a gas breakthrough in the industry today is to limit the drawdown of a well in such a way that the gas-oil contact will not reach the well."
Some recent events in the gas and oil zones of Bangladesh bear testimony to attempts being made to reduce the influx of natural gas before mining of oil. Burning of gas in Tengratila and carelessness in the events of gas spoilage in various places of Comilla, Chittagong, and Sylhet are indicative of the concerns of a vested group willing to go for an easy catch of oil in the Bay.
Although negotiations with foreign oil companies have been taking place since independence, no agreements were reached because they wanted an unusually profitable share of our resources in the name of technical assistance. However, the people were quite in the dark about the deposit of oil resources in the coastal area of Chittagong.
The intention of this article is to ask whether it is necessary for Bangladesh to go for oil-mining before full utilisation of her gas resources. Although natural gas can be used for the same purposes as oil, the liquid product is easier to transport.
Liquefaction of natural gas is uneconomical compared to direct pumping of the liquid fraction of the hydrocarbons. However, both gaseous and liquid fractions are equally valuable for Bangladesh. Delay in oil-mining can ensure a higher yield in terms of the total output of energy.
Petrobangla has recently installed a gas plant in Narsingdi without the so-called technical assistance of any foreigners. These engineers are capable of oil exploration, mining, and refining in fractionating columns. The next step is transportation to the specific stations for in-country use and for export. What is needed is the belief that the job of oil exploration and production can be done without assistance of foreign personnel. All that Bangladesh needs to buy from abroad are the required equipment and machinery for the purpose.

Abid Anwar is a chemist, poet and literary critic.