technical summary

Borders & Southern’s acreage is located in the South Falkland Basin, a frontier basin extending to the south and east of the Falkland Islands. Six wells have been drilled in the basin. In 2012 Borders & Southern made the first significant hydrocarbon discovery with exploration well 61/17-1.

The South Falkland Basin contains a marine depositional sequence. This contrasts with the lacustrine sediments found in the North Falkland Basin. Good quality marine source rocks of Early Cretaceous age have been proven in the exploration wells. These source rocks appear to have a wide distribution. Similar Late Jurassic to Early Cretaceous source rocks are recorded in DSDP wells located to the east of the Falkland Islands and in exploration wells located in the contiguous Malvinas and Magellanes Basins to the west. Early Cretaceous and Tertiary clastic reservoirs provide the main exploration targets. Good quality Early Cretaceous shallow marine sandstone reservoirs have been proven in exploration wells.

Whilst a large part of the basin is represented by a simple passive margin sequence containing mainly stratigraphic traps, Borders & Southern’s acreage is characterised by abundant structural traps. These are related to both early extensional faulting and later folding and thrusting.

technical summary

North–south cross section through Borders & Southern’s acreage.

Exploration activity

  • 2005   acquired 2,862 km of 2D seismic
  • 2008   acquired 1,492 square km. of 3D seismic
  • 2012   drilled two exploration wells
  • 2013   acquired 1,025 square km of 3D seismic

Well results

61/17-1 (Darwin)

Tilted fault block
Gas condensate in good quality Early Cretaceous sandstone reservoir

61/25-1 (Stebbing)

Thrust-cored anticline
Very strong gas shows (C1 to C5) in poor quality Tertiary reservoir
Unable to reach Upper Cretaceous targets due to anomalous pressures