Mir Moinul Huq Memorial Lecture Series: Hydrocarbon Prospect at Eastern Fold Belt of Bengal Basin

The eighth episode of ‘Mir Moinul Huq Memorial Lecture Series’ was held virtually on 31 July 2021. The session was chaired by Mr. Nazmul Hossain, who joined from Houston. The coordinator was Nazim Ahmed from Calgary and the session was moderated by Jasim Uddin in Dhaka. Arif Mohiuddin Sikder, Ph.D., Associate Professor, Center for Environmental Studies, Virginia Commonwealth University of USA was the keynote speaker and presented a paper on “Hydrocarbon Prospect of Eastern Fold Belt of Bengal Basin”. About eighty geoscientists of Bangladesh origin from around the globe including Bangladesh, Canada, USA, UK and Norway participated in this webinar.

Dr. Sikder mentioned in his presentation on eastern hilly region of Bangladesh that a part of the Eastern Fold Belt of Bengal Basin, which is one of the largest and least explored fold thrust belts of the world. He gave a brief account on the history of oil and gas exploration in the Chittagong, Chittagong Hill Tracts and Sylhet areas. He explained that the geological structures of the eastern hilly region are complex and reflection seismic is of little use. However, successes from same geological province across the border necessitates a re-evaluation of the prospect for hydrocarbon in that areas. It requires a clear understanding of the petroleum system of the target area-based in-depth geological knowledge.

Dr. Sikder said that after the independence of Bangladesh, very few attempts were made in exploring hydrocarbon in the hilly areas. In 1984, Petrobangla drilled a well up to 4005m in Sitakund structure with a lot of technical difficulties – the completion of the well took more than 4 years and even couldn`t reach the targeted depth. The only other well drilled was at Sitapahar structure by Shell Oil Company in 1986 and the well was also abandoned at the depth of 1650m due to experiencing many difficulties during drilling. In 1989, BAPEX drilled a well in Patharia anticline, but the well was abandoned due to very high deviation and hole problem. Considering perspectivity of Eastern Fold Belt, Dr. Sikder emphasized on taking exploration program in the different structures which were already identified.

Mr. Anisur Rahman, Senior Secretary at the Ministry of Power, Energy and Mineral Resources, was the Special Guest at the webinar. He appreciated Dr. Sikder for deliberating his nice technical presentation. He gave due emphasis to conduct seismic survey quickly in all the potential areas of Bangladesh by BAPEX and through out-sourcing where seismic survey has not been completed yet. 

He informed the event about the short-term gas demand, production, supply and shortfall up to 2024 which are as follows: 

            Figures in MMcfd

Mr. Rahman emphasized that BAPEX should try to replenish the gas shortage through exploration. There are 24 projects of BAPEX already approved by the government for exploration, development, work overs, setting up process plants etc. In order to deal with the ongoing gas crisis, there is an urgent need to explore oil & gas in the Chittagong and Chittagong Hill Tract areas. BAPEX is working on engaging JV partner(s) in the identified structures such as Patiya, Jaldi, Kasalong, Sitapahar, Ulahtong, Matamuhuri, Barkal, Utan Chatra, Gobamura etc. In light of this, instructions were given to BAPEX to call for Expression of Interest for JVA with reputed IOCs.  BAPEX is also in the process of re-inviting EOI to engage JV partner for exploration in the Atgram, Patharia, Sitakunda and Kosba structures.

Mr. Rahman expressed his deep appreciation for arranging this kind of technical session for geoscientists on a regular manner in remembrance of Mir Moinul Huq. He appreciated the organizer, geoscientist community of Bangladesh and abroad for remembering him with due respect and honor.

Md. Jasim Uddin, former exploration geologist who served in Petrobangla, BAPEX and IOCs, made a short presentation on “Chittagong Hills Exploration Scenario” as a speaker. He explained technical aspects and perspectivity of that area. He informed that at least four types of plays have been developed in Chittagong and Chittagong Hill Tracts region. Two of these are shallow and deep Miocene turbidite targets, a third play is Miocene paleo-structures, and a fourth is Miocene basin floor fan. The latter two plays have significant reserve potential but would also require considerably more seismic data acquisition in order to establish a drillable structure. The turbidite facies contain interbedded thick sandstones and shales which would provide both reservoirs and sealing beds. In addition, the deeper and more down-dip turbidite facies could contain very attractive source rocks. Shale within the Miocene turbidite sequence appear to have better source rock quality than that found in the shales deposited in shelf environments which dominate the samples from wells so far analyzed. He informed that numerous oil and gas seepages found in the different areas and Chara`s of Sitakund and Kasalong structure. Apart from experienced oil and gas shows in different wells of Sitakunda, Sitapahar (21m net gas pay logged), gas flowed at Jaldi #2 up to 8.6 MMcf/d at 3200m and indication of oil at Jaldi #3 and found good gas shows at 3950m in Halda #1. In addition, many gas samples were collected from surface seeps of Kuttal Chari, Rumba Chari, Basant Chari, Paindu Khal etc.

M. Farid Uddin, Consultant of BAPEX and former Vice President of UMIC operation in Bangladesh, sharing his observations on exploration in Chittagong Hill Tracts areas where IOCs either through PSC or by doing Joint Venture with BAPEX should be given opportunity. Chittagong Hill Tracts is the only region where there is assured possibility for hydrocarbon discovery in the shortest possible time. Surface oil seepages were detected at Barkal, Sitakunda and other areas. Shell did exploration in 1986 at Sitapahar. But they abandoned their works following Shanti Bahini abducting two officials of Shell. Traces of oil were found during drilling at Patiya #1 in 1953. In addition to oil at Sitaphar and Patiya, there exists stranded gas resource.

UMIC signed PSC with Petrobangla for oil, not gas while Ocean Energy was their associate. In 1999, oil price in the global market dropped below US$ 6.0 per barrel. If the prospects of Chittagong Hill Tracts are explored, there is a good possibility of finding oil and gas. Exploration must start at Patiya, Sitapahar, Kasalong, Shishak and Jaldi structures without further delay and may start to find out IOC(s) as joint venture partner of BAPEX. He suggested carrying out exploration in the stranded gas field like Sitapahar, Payiya and Jaldi.

Badrul Imam, Honorary Professor of Dhaka University opined in a follow up discussion that there were 11 gas fields discovery in Tripura where similar geological conditions prevailing like Chittagong and Hill Tract areas. In the south of Chittagong Hill Tracts, a number of large gas fields has already been discovered in the offshore Rakhine Basin of Myanmar. But there is a very little exploration carried out in our hill tracts and a lot of data and information are also available now. However, further studies and analyses are required. He believed that there is a good chance of oil and gas discovery if we do extensive exploration works in the identified structures. Our energy security is now mostly dependent on imported LNG, fuel and electricity. Considering economic point of view, it is necessary to carry out exploration in the hill tracts by BAPEX along with reputed IOCs as soon as possible.

Dr. Anowar Hossain Bhuyia, Department of Geology, Dhaka University and Consultant Geologist of BAPEX, took part as a discussant and expressed his satisfaction over rendering his consultancy services to BAPEX and working with them. He expressed his optimism regarding capability of BAPEX and their ongoing basin modelling work. He said that only 17 wells have been drilled so far in the Chittagong and Chittagong Hill Tracts area with only one gas discovery at Semutang but experiencing oil and gas shows in the different wells which is very good indication for migration of oil and gas. He also mentioned that earlier mind set was for getting oil discovery while proper attention was not given to find gas. However, BAPEX is in the process of taking exploration program in the hill tracts and to find out good JV partner.

Mohammed Ali, Managing Director of BAPEX, as a discussant informed that BAPEX has taken extensive seismic program and future planning for conducting 2D and 3D seismic surveys. As part of the program, BAPEX in the process of undertaking different surveys in the upcoming dry season at exploration blocks 15 and 22 by engaging foreign geophysical company which is at its the final stage and survey will start in the upcoming dry season. The details of seismic survey program are as follows;

It is nice to know that all the projects have already been approved by the government under financing from Gas Development Fund. Based on 2D, 3D seismic and geological data, projects will be undertaken for workover of Semutang well # 5 & 6 and drilling of Semutang well # 7. In addition, BAPEX is working on preparing an outline for future exploration woks in the hill tracts and engaging JV partner(s) through tendering process.

Mortuza Ahmad Faruque, Former Managing Director, BAPEX