Is sanding in Bibiyana a wake-up call?

File Photo: Star

The Bibiyana gas field in Bangladesh's Habiganj district is the highest quantity gas producer in Bangladesh. Operated by the US-based energy corporation Chevron, it alone produces about 1,250 million cubic feet per day (mmcfd) of gas, which is more than 50 percent of the total national gas production (2,370 mmcfd). In fact, out of the 20 gas fields in production across the country today, 16 fields cumulatively produce only 15 percent of the total daily production, while the remaining four contribute 85 percent. Next to Bibiyana stands the Titas gas field, which produces about 400 mmcfd, just about one-third of what Bibiyana produces daily. While individual wells in the Bibiyana gas field produce about 50-60 mmcfd on an average, those in other gas fields produce four to 20 mmcfd.

All this data tells us why Bibiyana is considered a safeguard for our national gas supply chain. Obviously, a major production glitch at Bibiyana will cause havoc in our entire gas supply system. This has never been clearer than during the recent gas crisis experienced on the first day of Ramadan. The day before the holy month started, sand and dirt appeared alongside gas through the production tube in the gas flow line. This alerted the production personnel, and six suspected wells in a single pad were closed to identify the affected well. Production is now down by 400 mmcfd and its impacts are too major to ignore. Many industrial units recorded low to no gas pressure, which seriously affected their production capability; several power plants switched to oil for fuel; domestic cooking was disrupted, to the frustration of people fasting; the CNG transport vehicles could not function due to the lack of gas at the refilling stations. Production resumed at the suspended gas wells a few days later, except for the one well with sand and dirt flowing out with gas. Chevron hinted that gas supply would return to normal in a few days after the well with the sanding problem was fixed.

This is what happened when production from only six gas wells in Bibiyana—which has 26 gas wells in production in total—was temporarily suspended. What would happen if the same thing happened with 10 wells or 15 wells, or if the present production plateau started falling gradually or dipped suddenly to a low level, as experts have predicted? The consequence of a major decline in gas production at Bibiyana will be disastrous due to the fact that there is no alternative to this gas field in the country at present. In case of such a disaster, the only option for Bangladesh to immediately fill the gap would be to ramp up its LNG import.

But increased LNG import will put more burden on our economy as the price of this fuel is still too high and there is no indication that it may go down any time soon. The Bangladesh Oil, Gas and Mineral Corporation (Petrobangla) estimates that the present level of LNG import accounts for only 20 percent of the total gas supply in the country and costs Tk 44,000 crore annually, while the remaining 80 percent is supplied from local gas fields, costing about Tk 6,000 per annum. Petrobangla already feels the pinch for paying for the high import bill, and has not received the subsidy it requested from the government. The bureaucrats in the administrative corridors do not seem to care much about what kind of economic equation they need to formulate, should they need to import LNG double, triple or quadruple the amount of the present volume!

Is the sanding in the Bibiyana gas well a wake-up call for Bangladesh? Sanding is the unwanted flow of loose sand with gas from an active gas well. This is a problem which, if not controlled properly, may cause equipment failure, production decline, pipeline erosion and so on. Eventually, a gas well may cease to produce and have to be abandoned. There are several causes behind the sanding of a gas well, among which high production rate, also referred to as overproduction, is an important one. High rate of production may cause formation damage and lead to sanding.

Is Chevron overproducing in Bibiyana wells? When this question was raised unofficially, technical personnel said that Chevron maintained international standards of reservoir management and did not overproduce gas in any Bibiyana well. However, data on the daily production of all the gas fields in the country are regularly updated on the Petrobangla website—a practice much appreciated in the public domain. The Petrobangla data shows that Bibiyana has a production capacity of 1,200 mmcfd, while the actual production is in the range of 1,250 to 1,300 mmcfd. Is this not a case of overproduction? When this question was asked to the technical person, again in an unofficial communication, they said the production capacity of Bibiyana was 1,300 mmcfd, not 1,200. Chevron has supposedly given this information to Petrobangla several times, and has sent a letter requesting a correction on its website, but Petrobangla has not complied yet.

Does Petrobangla accept Chevron's claim that Bibiyana's production capacity is 1,300 mmcfd, or does it not? It is a very important question, because if Petrobangla maintains that Bibiyana's production capacity is 1,200 mmcfd, then it should direct Chevron not to overproduce gas at that field. This is a crucial technical issue that should be settled amicably between Petrobangla and Chevron. Bangladesh cannot meet its gas demand, and supply shortfall runs between 800 and 900 mmcfd. An undersupply gas network system cannot risk overproduction, because it may lead to formation damage and eventually the loss of the active gas wells.

Bangladesh seems to be ill-prepared to manage a sudden shortfall in gas supply from the existing gas fields. The main reason behind that is, in spite of having highly prospective gas reserves by global standards, the country never undertook robust and sustained exploration of gas in potential land or offshore reserves. Bangladesh's success over securing a large sea area from Myanmar and India was followed by joyful celebration only. We have not learnt from Myanmar and India's successful exploration and discovery of large gas reserves in their respective areas in the Bay of Bengal. We have to wake up and do the needful to begin gas exploration to avoid a major energy crisis.


Dr Badrul Imam is a former professor of the Department of Geology at Dhaka University.


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