Oil India Limited (OIL) is planning to conduct a 3D seismic survey of 4,000 sq km of land in Upper Assam, while exploration in Nagaland is expected to commence when the climate is conducive. The company has also explored 3000 sq. km areas in Nagaland. OIL has considerable potential in the Assam- Arakan fold belt and believes that both areas have the same potential, according to Dr Ranjit Rath, chairman and managing director.