The Sangaw North-1 exploration well has been drilled to a depth of 3,396m, approaching the depth at which the company plans to run casing prior to drilling into the Jurassic reservoir targets.
While drilling at this depth, the well encountered a zone of high formation pressure with the result that hydrocarbon gas, containing approximately 0.5% hydrogen sulphide, entered into the well and pressure was observed at the surface.
While conducting operations to remove the gas from the well and eliminate the surface pressure, the drill pipe parted at a depth of approximately 850m.
The company plans to circulate-out any further influx of gas from the well bore, eliminate the surface pressure, and retrieve the drill pipe and bottom hole drilling assembly from the well.
The entry of hydrocarbon gas into the well, whilst encouraging, does not provide information as to the potential for material hydrocarbon accumulations in the Jurassic reservoir target, the company said.
Wire line logs and flow tests will be required to evaluate any potential reservoirs encountered and these have not yet been acquired, Sterling said.
Sterling chairman Alastair Beardsall said that the company is focused on successfully completing the current operations in a safe and reliable manner.
"Once this is done, well operations will continue to evaluate the potential of the Jurassic reservoir targets," Beardsall said.
