The initial evaluation of the Saiwan East-2 well on Block 4, onshore Oman, has been completed. An over 400 metres column of heavy oil saturation in the upper target formations has been confirmed. A deeper lighter oil zone was also confirmed, and has produced 280 BOPD on test. The drilling rig has been released and the well has been suspended awaiting productivity testing of the heavy oil zones later this year.
The Saiwan East-2 well was drilled to a total depth of approximately 2,450 metres. As anticipated, logging confirms the presence of heavy oil in all three expected formations in the upper parts of the well. A gross heavy oil column of more than 200 metres covering both the Miqrat and Amin sandstones has been measured. Oil saturation is also calculated in the Buah limestone formation, resulting in a total of more than 400 metres of gross heavy hydrocarbon saturation measured in Saiwan East-2.
The well was drilled deeper than originally planned to further investigate previously undrilled layers of the Saiwan East structure. The deepening of the well encountered oil in the Khufai limestone section. A gross oil bearing section of 27 metres was measured from the logs. This zone was tested, and flowed 280 BOPD of 33 degree API oil on a 24/64 inch (9.5 mm) choke. No water was produced and the oil contained a very low Gas Oil Ratio (GOR).
The drilling rig has been released and the well has been suspended pending production testing of the heavy oil zones later this year. A smaller rig will be used for this testing. Pressure gauges have also been installed at the bottom of the well for an extended pressure test expected to be completed in late June. Several cores have been obtained which will undergo detailed analysis.
“Block 3 and 4 continue to exceed our expectations. The logging and coring has confirmed that we have huge amounts of heavy oil in place, although actual production testing of these zones still remains. We have also made a new oil discovery of lighter oil. It is too early to say if this discovery will be commercial, but it could well turn into a project of its own,” says Magnus Nordin, Managing Director of Tethys Oil AB.
Tethys has a 50 per cent interest in Block 4. CC Energy Development (Oman) SAL holds the remaining 50 per cent and is operator.