Australian producer Santos announced Tuesday that it has achieved first oil from the Van Gogh infill project, marking the completion of a two-well program to increase production from the field.

The Santos-operated Van Gogh field is one of three subsea oil field developments located in the Exmouth Basin, offshore Western Australia, which tie into the floating production, storage and offloading vessel (FPSO), the Ningaloo Vision.

The infill project began in September and involved drilling and completing two subsea wells and connecting them into existing offshore infrastructure.

The two dual-lateral wells were targeted to access bypassed oil not drained from the original wells and were technically the most challenging of any wells in the development, drilling horizontal sections in the reservoirs as long as 3,500 meters only 950 meters below the seabed.

Production from Van Gogh began in 2010, with the nearby Coniston and Novara fields tied back to the FPSO in 2015 and 2016, respectively.

Santos has a 52.5 percent interest in the Van Gogh-Coniston-Novara project, which it operates.