Abstract:
Present study is carried out in Toot area, Potwar Sub Basin. Reservoir rock
typing and Saturation height modeling is carried out for Toot-16, Toot-17 and Toot-
18 wells. The reservoir is the sands of the Datta Formation of Jurassic age at an
approximate depth of 4,500 meters. All three wells were declared as Oil producers.
Petrophysical interpretation include evaluation of porosity, permeability, lithology,
volume of shale and water saturation. Average effective porosity for Datta formation
as approximately 7-8%, which indicates a good quality reservoir. Water saturation is
from 20 – 90 % and average water saturation for clean sands of Datta formation is
ranging from 25-30%. Well correlation shows heterogenous sequence of sands of
Datta Formations in all three wells. The distance between the well Toot-16 to Toot-
17 is approx. 1.6 km, Toot-17 to Toot-18 is approx. 2.1 km and Toot-18 to Toot-16
is approx.
Reservoir rock typing (RRT) are computed using core porosity and core
permeability data by using Flow zone indicator (FZI) approach in the Datta
formation. Three rock types have been identified. RRT-1 is comprised of bad quality
rock where the Permeability is less than 1 mD and Water saturation is more than
90%. RRT-2 is comprised of moderate to good quality rock where the Permeability
ranges from 1-10mD and Water saturation is more than 40%. RRT-3 is comprised
of very good quality rock where the Permeability is greater than 10 mD and Water
saturation is less than 40%.
Saturation height modeling is performed by using Special core analysis
(SCAL) data of Toot-16, 17 and 18 wells. Out of five functions, Lambda function
is best fitted in Toot wells. In Datta Formation, water saturation calculated from the
Lambda model and water saturation computed from wireline logs are favorably
matching with one another.
