ABSTRACT: Kesanapalli-West Pay Sands: an Integrated Study
Lahiri, Gopal1, A.D. Mathur2, S. Chawla2,
S. P. Rana2, and S. K. Mitra2
(1) ONGC LTD, Gujarat, India
(2) ONGC-Schlumberger Joint Research Centre, New-Delhi, India
The Matsyapuri sandstone within the Tertiary section is an hydrocarbon producer in the Kesanapalli-West field. The field is located on an island of the Krishna-Godavari basin of India. The structure of the field trends ENE-WSW and a section of it extends offshore. The prograding delta inputs and syndepositional tectonics haven given rise to hydrocarbon pools.
Four major sand-shale sequences have been identified within the lower part of the Matsyapuri sandstone. The shales are correlatable but the adjoining pay sands seem to have no consistent hydrodynamic continuity. Facies analysis and borehole images study give a new insight to the delta reservoir sands. Seismic data close to pay levels reveals major growth and normal faults.
On density-neutron overlays, most of the sand layers appear to be gas bearing and have been proven so by testing, barring some cases where the zones have produced oil instead of gas. It is only through a full petrophysical evaluation routine, including both oil and gas in the model, that the oil layers can be differentiated from the gas layers. These oil zones have high permeability and high Productivity Index, with large aquifer support.
The wells falling within specific structural closures are hydrocarbon bearing. These structures are limited in areal extent and control the entrapment of hydrocarbon at different stratigraphic levels. Wells falling outside of these closures are non-producing.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia