Tullow Oil plc (Tullow) has announced oil discovery at its Carapa-1 exploration well, offshore Guyana.

Tullow said preliminary results of drilling, wireline logging, pressure testing and sampling of reservoir fluid indicated the discovery of oil in Upper Cretaceous age sandstone reservoirs.

Rig site testing has indicated that the oil is 27 degrees API with a sulphur content of less than 1%. A detailed laboratory analysis of the oil quality will follow in due course.

The Carapa oil discovery suggests the extension of the Cretaceous oil play from the Stabroek license southwards into the Kanuku license. While net pay is lower than pre-drill forecasts, the 27 degree API oil supports the significant potential of the Cretaceous play on both the Kanuku and adjacent Orinduik licences.

“The Valaris EXL II jack-up rig drilled the Carapa-1 well to a Total Depth of 3,290 metres in 68 metres of water and the well will now be plugged and abandoned. Repsol Exploracion Guyana, S.A. is the operator of the Kanuku block with a 37.5% stake,” a press release posted on the company’s website said.

Tullow Guyana B.V. also holds a 37.5% stake with Total E&P Guyana B.V. holding the remaining 25%.

Mark MacFarlane, Chief Operating Officer, commenting today said: “The Carapa-1 result is an important exploration outcome with positive implications for both the Kanuku and Orinduik blocks. While net pay and reservoir development at this location are below our pre-drill estimates, we are encouraged to find good quality oil which proves the extension of the prolific Cretaceous play into our acreage. We will now integrate the results of the three exploration wells drilled in these adjacent licences into our Guyana and Suriname geological and geophysical models before deciding the future work programme.”