Geology and Hydrocarbon Potential of Offshore Indus Basin, Pakistan: GEOLOGIC NOTES

Abstract

The Indus offshore basin, located in the south of the Karachi trough and Thar slope, between Murray Ridge and the Indian border (23 to 25°N lat.; 66 to 68°E long.) has been investigated geologically from the point of view of hydrocarbon potential. Nine wells were drilled in the area: two onshore wells (Karachi 1, 2), three wells near the Karachi shore (Dabbo Creek, Patiani Creek, and Korangi Creek), one well on the offshore platform (Karachi South A-1), and three wells in offshore depressions (Indus Marine A-1, B-1, and C-1). No oil or gas deposit was discovered, but gas shows and traces were recorded. However, considering the large area (7,700 mi2; 20,000 km2) the number of wells drilled represents an insufficient effort of exploration and drilling. Tectonically, the Indus offshore basin can be divided into three units: (1) an offshore depression on the west, between Murray Ridge and the hinge line; (2) the offshore Karachi trough platform in the middle between the hinge line and the Karachi shoreline; and (3) offshore Thar slope platform or Indus River deltaic area on the east. The hinge-line zone and the outer margin of the carbonate platform, where there is a possibility of reef buildups, seem to be potential areas for hydrocarbons, and further investigation and drilling for suitable structural traps should be pursued.