– detailed evaluation of data will be conducted, says Westmount Energy

EXXONMOBIL has discovered “heavy oil” at its over US$100 million Tanager-1 well, which is located in the Kaieteur Block.
As defined by the U.S. Geological Survey (USGS), heavy oil is a type of crude oil characterised by an asphaltic, dense, viscous nature (similar to molasses), and its asphaltene (very large molecules incorporating roughly 90 per cent of the sulfur and metals in the oil) content.

Based on information from Westmount Energy, a shareholder in the Kaieteur Block, evaluation of Logging while drilling (LWD), wireline logging and sampling data, confirm 16 metres of net oil pay in high-quality sandstone reservoirs of Maastrichan age. This is the first discovery at the Kaieteur Block.
Preliminary evaluation of the fluid samples from the Maastrichan reservoir shows heavier oil than is reported from the Liza Phase One crude analysis. This discovery, according to Westmount, is currently considered to be non-commercial, as a stand-alone development.

But these samples will be the subject of further detailed laboratory analysis over the coming months.
Westmount said the Tanager-1 exploration well is the deepest well drilled in the Guyana-Suriname Basin to date. It was spudded on August 11, 2020, using the Stena Carron drillship, and reached a total depth of 7,633 metres in recent days.

“Although high quality reservoirs were also encountered at the deeper Santonian and Turonian intervals, interpretation of the reservoir fluids is reported to be equivocal at this stage and requires further analysis. It is anticipated that the well will now be plugged and abandoned in the coming days.
“The Tanager-1 results confirm the continuance of a cretaceous petroleum system and the Liza play fairway onto the Kaieteur Block, down dip from the prolific discoveries on the neighbouring ExxonMobil operated Stabroek Block,” said Westmount.

The company said the Kaieteur Block partners will now conduct a detailed evaluation of the data collected at Tanager-1 with a view of understanding the well result, re-calibrating the seismic model for this part of the basin and high grading the next potential drilling targets on the Kaieteur Block.
ExxonMobil is operator at the Kaieteur Block and holds 35 per cent interest with Cataleya Energy Limited holding 25 per cent, Ratio Guyana Limited 25 per cent, and Hess 15 per cent.
Westmount holds approximately 5.4 per cent of the issued share capital of Cataleya Energy Corporation and around 0.7 per cent of the issued share capital of Ratio Petroleum Energy Limited Partnership.

The Kaieteur block is adjacent to the Stabroek Block which has delivered 18 substantial oil discoveries since 2015, with reported discovered recoverable resources of over nine billion oil-equivalent barrels to date.