The location is between the Horndean and Singleton producing oil fields and is assessed to be an extension of the former.
The final measured depth will be 6009ft (1831m) at a true vertical depth of 4528ft (1380m), and electric logs will be run to evaluate their well potential.
Northern Petroleum managing director Derek Musgrove said that the commercial case for drilling Markwells Wood -1 is compelling when the price level of oil is above $80 per barrel for Brent crude oil.
"The independent consultants RPS Energy report in February 2010 assessed the Markwells Wood recoverable proven plus probable oil reserves at 5.7 million barrels and stated a value of £24.75m based on an $80 oil price for our 50% interest in Markwells Wood."
Northern Petroleum is an oil and gas company with exploration, development and production assets in the Netherlands, Italy, UK and Guyane.
