CALGARY, Canada — Valeura Energy has drilled two successful appraisal wells on the flanks of the Wassana oil field in the Gulf of Thailand, the goal being to test for suspected additional oil accumulations in the Tertiary clastic section.
Both wells targeted the deeper portions of the 2.0 and 2.1 sands that hold most of the field’s remaining oil reservoirs in the field. Prior drilling had not established an oil-water contact in this section, implying potential for further downdip oil volumes.
The first well, A28, drilled in Wassana’s main producing fault block, downdip of existing production wells, encountered 72 ft of net oil pay and the presence of oil down to at least 5,594 ft TVDSS, exceeding expectations for the vertical extent of the oil column.
In addition, the well penetrated thicker reservoir sands and new oil-filled sands that had not been previously developed.
The second well, A28-ST1, drilled to confirm the presence of oil in an untested area south of the main producing part of the field, delivered 75 ft of net oil pay.
Currently, Valeura is re-mapping the field to integrate the new data and expects to upgrade its volumetric estimates. It now believes 20 production well targets could be viable within the reservoir section appraised by the two wells and has started the concept select phase to expand development of Wassana.
This would likely involve adding further wellhead and oil processing structures for use as a higher-capacity production hub than is currently available through the existing mobile production facility.
The drilling rig has since transferred to start a four well drilling program on the Jasmine Field comprising two new production wells and two appraisal wells to support further production drilling in 2024. It will then relocate to the Nong Yao oil field for a five-well infill campaign.
Production operations at Wassana remain suspended as Valeura conducts a review of safety and operating practices of the third-party-owned and operated FSO. The company has now decided to bring in a new subcontractor to operate the vessel and plans a phased transition program leading to a resumption of production later this year.
09.19.2023
