Soco plans well on Block 16-1 off Vietnam

By OGJ editors
HOUSTON, Sept. 27 -- Soco Vietnam Ltd. is preparing to drill the Voi Nau 1X (VN-1X) exploration well on the AA prospect on Block 16-1 off southern Vietnam. Drilling is expected to take 20 days.

The AA prospect is on trend with Voi Trang oil field, which was discovered in 2002 by the Voi Trang 1X well.

The planned VN-1X well will be drilled with the same rig used to drill the recent Te Giac Lam 1X (TGL-1X) exploration well, which is also on Block 16-1 and the first well on Prospect O.

The TGL-1X well, drilled to 3,697 m TD, was designed to test a Miocene four-way closure on one of the basement ridges that appear on seismic to be analogous to Te Giac Trang field, discovered to the east.

TGL-1X was deepened to intersect the Oligocene sands. Although the well was drilled overpressured, mud log data indicated 70 m of sand with good oil shows in the Oligocene section. However, a test of this interval found that the sands at this location were tight, and further testing was discontinued. The test data will be further analyzed to determine future drilling on this new play type, Soco said. Meanwhile, the TGL-1X well will be plugged and abandoned.

After drilling the VN-1X well, the rig will be fitted with high-pressure equipment, including a 15,000 psi blow-out preventer, to enable testing of the Te Giac Den 1X (TGD-1X) well on Prospect E.

The TGD-1X well encountered hydrocarbons in two Oligocene clastic sequences, which were separated by a volcanic layer. Well logs over the upper sequence, the object of the impending test, indicated about 30 m of net pay.

After drilling through the volcanics, the well also encountered a deeper high-pressure clastic sequence with oil and gas shows. A further 300 m of sediment is interpreted above the basement. This interval will not be reentered on this test, but will be redrilled later in the drilling program, Soco said.