The petrophysical aspects of the Datta Sandstone was carried out by using the wire-line logs of Chonai-01 well which suggests effective porosity (0.151%), average porosity (0.241%), density porosity
about 0.217%, saturation of water averages 0.986% and saturation of hydrocarbons about 0.0139%.
The drilled rock units range in age from Pleistocene to Pre Cambrian.The Petrophysical characteristics investigated are Lithology, Volume of shale (Vsh), Density Porosity
(D), Neutron Porosity (N), Sonic porosity (s), Effective Porosity (E),Water Saturation (Sw), Bulk density (pb) and Bulk Volume ofWater (BVW).
The neutron porosity (phN), density porosity
(phD), total porosity (phT) and effective porosity (PHIE / phE) were calculated using the following formulae (Rider, 1996; Asquith and Gibson, 1982; Crain, 1986);
Lockhart Limestone has a thickness of 170 m from the depth of 4229m to 4399m, while the calculated porosities are sonic porosity 3.6%, neutron porosity 6.7% and density porosity
11.4% in addition to that total porosity and effective porosity of Lockhart Limestone turns out to be 9.1% and 8.4% respectively (Table 1).