Tethys Oils test production from the early production system (EPS) on Omans Block 3 and 4 reached 339,270 barrels of oil last month
The company has a 30 per cent interest in the blocks which amounts to 101,781 barrels.
The Swedish oil firm has been carrying out long-term production tests on wells in the Farha South oil field on Block 3 and Saiwan East oil field on Block 4.
Tethys said that production rates have continued to vary depending on test programme design and available capacity.
The company had also initiated the preparation work, at the end of May, for the launch of the export pipeline connecting the oil fields with the national Omani transportation system.
The pipeline work which had affected the oil production last month is expected to continue to have an impact on the output in June.
The export pipeline would be operational before the end of the second quarter, according to Tethys.
The company's partners, Mitsui E&P Middle East and CC Energy Development, Oman have 20 per cent and 50 per cent interest respectively in EPS.
