|
In early 2008, block operator Tap Oil (Philippines)
Pty Ltd completed their ranking of the top drillable prospects
identified in the 3D seismic data acquired in July 2007. The Lumba
Lumba Prospect came out first in the ranking, the others, in their
order of relevance, being Mirapina, Wahoo, Aardvark and Moose West.
During the same period, Tap Oil finalized negotiations for a
drilling rig to be mobilized in the Sulu Sea area by June 2008. The
semi-submersible rig “TransOcean Legend” owned by TransOcean was
selected for the drilling campaign.
In May 2008, Tap Oil presented for approval by the
Joint Venture the program and budgets for potential two (2) wells
which they plan to drill back to back. Tap Oil offered to drill the
second well on a sole-risk basis with their partner Salamander
Energy but would allow the Filipino partners to back-in by paying
consistent with the SC 41 Joint Operating Agreement. The partners
negotiated for a reduction in the premium which the operator turned
down.
The Lumba Lumba-1 well was programmed to test
multiple reservoir targets in a series of interpreted channel and
fan complexes with a planned minimum total depth of 2,250 meters
true vertical depth (TVDss), to be deepened in the event of
encouragement such as presence of significant oil shows or oil on
wireline logs.
Tap Oil spudded the well on July 19,
2008 in 1,107 meters water depth. After running and setting the 2
upper casings and while drilling the 17 ˝-inch section of the hole,
the operator observed that the guide base moved some 2 meters down
and the string weight increased. Further cementing appeared to have
abated subsidence, but Tap Oil observed large chunks of cement in
the guide base and attempts to break up and clear the wellhead
housing all failed. The operator decided to plug the well, moved
the rig to a new location and spudded the Lumba Lumba- 1A well on
July 27, 2008.
Based on wireline logs and drilling
returns, the Lumba Lumba- 1A did not encounter reservoir-quality
formation at its two shallow primary objectives although elevated
gas readings up to C5 were observed. Due to deteriorating wellbore
conditions, Tap Oil decided not to proceed to the deeper secondary
objectives. The well was eventually plugged and abandoned as a dry
hole on August 20, 2008. The well reached a final depth of 1,678
meters TVDss.
The DOE, in a letter to Tap Oil,
extended the term of Service Contract 41 to enable the operator to
undertake pre-stack time migration and inversion of the 3D dataset.
Tap Oil aims to rectify seismic data quality issues, the result of
which is seen to greatly contribute in the de-risking of numerous
prospects and in the selection of the next prospect for drilling.
An Australian geophysical contractor, DownUnder Geosolutions, was
contracted to perform the data processing work. As of time of
writing, the contractor has completed about 70% of the whole tasks
which also include seismic inversion, rock physics, and
lithological/liquids analysis. Total budget for the program is USD
812,220.00. PHILODRILL’s share in the costs is about USD 27,600.
|
