Abstract

In the last few years, many gas accumulations were discovered in Vietnam within Oligocene to Pliocene carbonates as well as clastic reservoirs. Gas fields have been found mainly in the Song Hong, Nam Con Son and Malay–Tho Chu basins, whereas oil fields were discovered only in the Cuu Long Basin.

Gas plays in the Song Hong Basin occur in Middle Miocene deltaic and Late Miocene-Pliocene marine sandstones. Resources total some dozens of TCF, contaminated by around 36% CO₂.

Two main gas plays have been identified in the Nam Con Son Basin: Middle to Upper Miocene carbonates and Lower to Upper Miocene sandstones. The carbonate play usually develops on structural highs. Clastic reservoirs are sand bodies deposited in deltaic or marine environments. The gas resource in these also reaches some dozens of TCF, but CO₂ contamination is lower.

In the Malay-Tho Chu Basin, gas was discovered in thin Miocene sandstone beds with reserves of a few TCF. In addition, a significant volume of associated gas will be available from current oil fields and future oil discoveries.

These plays highlight the high potential of Vietnam for producing gas in the next few years. At present, gas markets have only been defined for gas fields about to reach production. Gas marketing efforts should be extended to keep pace with the increase in exploration, development and production of gas in the Vietnam region.