The search of oil and gas in the area constituting Bangladesh began in the later part of the 19th century through some sporadic geological mapping. The first serious attempt to find oil and gas was undertaken in Sitakund in 1908 by the Indian Petroleum Prospecting Company. During 1923-31 Burmah Oil Company (BOC) drilled two shallow wells in Patharia. The wells were abandoned though there was a reported occurrence of oil. A total of 6 exploratory wells were drilled, the deepest being 1047 meters. There was however no discovery and the Second World War disrupted further activity.

The promulgation of Pakistan Petroleum Act in 1948 infused interest of international oil companies in oil and gas exploration. The Standard Vacuum Oil Company (STANVAC) of USA, Pakistan Petroleum Ltd. (PPL) - a Burmah Oil Company affiliate and Pakistan Shell Oil Company (PSOC) took up concessions during early fifties. STANVAC drilled 3 wells without success. PPL drilled several wells and made the first gas discovery in Haripur in 1955 followed by Chhattak in 1959. PSOC was the most successful company and discovered 5 gas fields. During this time Oil and Gas Development Corporation (OGDC) was established in the national sector in 1961.They drilled wells in Jaldi and Semutang, discovering gas in Semutang in 1970.

After the liberation of Bangladesh, Petrobangla was formed and in 1974 the Bangladesh Petroleum Act was enacted. The offshore area of Bangladesh was divided in to 6 blocks, which were taken up by Ashland, ARCO, BODC (Japex), Union Oil, Canadian Superior Oil and Ina Naftaplin under Production Sharing Contract (PSC). These companies drilled 7 offshore wells resulting in discovery of Kutubdia offshore gas field.

The 1980s saw accelerated exploration activities by Petrobangla, which drilled 12 exploration wells and discovered 7 gas fields. Among these Fenchuganj well remains the deepest drilled well in Bangladesh (4977m). Meanwhile a new milestone was achieved when Petrobangla discovered the first commercial oil pool in Sylhet-7 on December 23, 1986. After formation in 1989, BAPEX has continued exploration for Petrobangla, and drilled 3 exploratory wells discovering gas in Shahbazpur and Saldanadi.

In 1981 Shell Oil Company was awarded a PSC. Shell drilled the Sitapahar and Salbanhat wells which were dry. In 1988 Scimitar Exploration was awarded another PSC. They discovered Jalalabad gas field. IDuring 1994-1997, eight blocks were awarded to six companies under PSC. Again during 2000-2001 four blocks were awarded to four companies. So far 13264 km 2D seismic, 1301 sq.km 3D seismic and 14 explroratory wells have been drilled in those twelve blocks. All these exploratory activities led to discovery of four gas fields namely Moulavibazar, Sangu, Bibiyana and Bangura-Lalmai. Currently all these four fields along with the previously discovered Jalalabad gas fields are in production.

Even though exploration history for oil and gas goes back almost a century, exploration density has remained very low. So far only about 75 exploration wells have been drilled, which resulted in discovery of 25 gas fields of sizes ranging from more than 4 tcf to 25 bcf GIIP. This indicates the extremely low exploration density but high success rate of 1 in three exploration wells.

Of the exploration wells, 17 are in the offshore with two discoveries and the rest 58 are on shore with 23 discoveries. It is of great significance that out of the 58 onshore wells 47exploratory wells were drilled in the eastern margin of the country with the discovery of 22 gas fields.