Reservoir Potential of Datta Formation, Hazara Basin, Pakistan

Abstract

    The Datta Formation of Toarcian age is predominantly a transgressive shoreface facies in the Hazara Basin. The four standardized lithofacies include Carbonate Facies (01), Argillaceous Facies (02), Arenaceous Facies (03) and Ferrogenous Hardground Facies (04) which have been subdivided into various microfacies.
The Datta Formation was deposited under repeated fluctuating sea level conditions. This predominantly clastic shoreface facies is, therefore, intercalated with the lagoonal shale beds, hardgrounds, carbonate shoals, lagoonal pelletoidal limestone horizons, glauconitic subtidal sandstone, minor shallow tidal channels and barriers which shows cyclic deposition.
The porosity of the Datta Formation in Hazara Basin generally varies from 1 to 7%. However in some upper shoreface horizons this formation has high porosity (upto 20%) and may serve as a hydrocarbon reservoir in northern Potwar.
The study of heavy mineral suits, their quantities, and shapes suggests a recycled origin for the clastic part of the Datta Formation.

Volcanic hosted massive oxide-sulfide deposits have recently been discovered in the subsurface in Hachi volcanics near Chiniot. Such deposits must exist throughout Kirana-Malani Basin west of the Aravalli Orogen.