Speakers at a seminar expressed their reservation about both estimate of gas reserve and the rate of its depletion in the country.
They found the reserve underestimated and the rate of depletion over-stated.
The experts on Saturday said hydrocarbon exploration activities both onshore and offshore were not enough as compared to other countries so that it could be said the country has limited natural gas prospect.
On the other hand, they added, it cannot also be stated that the gas resource is depleting fast as the exploration is yet to be completed.
Bangladesh remained one of the least explored petroleum provinces in the world, with only one well in every 2,215 square kilometre (sq km) in case of onshore exploration, they maintained.
In the offshore, the well density is even worse -- one well in every 5,000 sq km as compared to one well in every 14 sq km in the Gulf of Mexico and one well in every 146 sq km in offshore India, they pointed out.
Forum for Energy Reporters Bangladesh (FERB) organised the seminar titled "Prospects of Bhola Gas Field and Energy Security" in the capital, where Prime Minister's energy adviser Dr Tawfiq-e-Elahi Chowdhury was the chief guest.
Professor Dr Badrul Imam of Geology Department of Dhaka University made a keynote presentation at the seminar, sharing the preliminary reserve estimates for two gas fields in Bhola.
Shahbazpur and newly discovered Bhola North have a cumulative recoverable reserve of up to 1.5 trillion cubic feet (Tcf), according to the estimates.
But further upscale reserve growth in Bhola is possible depending on additional appraisal and exploratory drillings in the island, he said, suggesting the government to move steadily for exploration of oil and gas especially in the southern coastal belt of the country.
The recent discoveries in Bhola have placed the island and its surrounding areas as a potential 'natural gas hot spot' in the making, he said. A dedicated exploration campaign was also recommended to truly unearth the reserve potential of the area.
"Exploratory drillings in Bangladesh till date target only the simple and easy-to-drill prospects," said the energy expert.
More complex stratigraphic prospects were not taken on board although the channel sand, incised valley fills, pinch out, unconformity, roll over and on-lap features are common in the mega delta geologic setting of the coastal belt, he added.
Prof. Imam also stressed on revisiting the database of earlier drilled wells in the southern coastal areas that proves the wells are not dry and shows signs of gas flow.
The PM's energy advisor said the government has been pursuing an energy policy that looks for diversified energy mix.
"We're importing LNG besides our gas exploration works to meet the growing demand of energy," he said. "The government is not only waiting for the exploration works."
He said the government was trying to bring the gas from Bhola field to the mainland of the country and utilise the energy for power generation and industrial purpose. The government has also a plan to connect it with the pipeline planned to be installed from Indian West Bengal to its northern region, he said.
Mr Chowdhury admitted that Bangladesh`s offshore exploration move was not successful, following the withdrawal of investment decision by international oil companies in the pretext of oil price fall in the global market.
Speaking at the seminar, Gazprom managing director Surgey Tumanov said his organisation had good exploration experience in the country as it was involved in Bhola exploration works and also elsewhere in the country.
Describing his experience as former project director of Bapex (Bangladesh Petroleum Exploration and Production Company Ltd) for Bhola gas field, Mr Amzad Hossain explained potentials in several islands of Bhola like Char Kazal, Char Jabber and Muladi.
Presided over by FERB chairman Arun Karmaker, the seminar was also addressed by chairman of Geology Department of Dhaka University Kazi Matin Uddin Ahmed.
Gazprom head of exploration Yuriy Aleksakhiv also made a presentation on their exploration experience in Bhola gas field as the company was involved with Bapex in the gas field drilling works.
