Abstract

Lanwa field is situated in the northern part of Cambay basin in Ahmedabad-Mehsana tectonic block. It is one of the fields of heavy oil belt that is aligned on the eastern fringe of Mehsana horst. The viscosity of the oil increases from south to north. The uppermost sand unit KS-I in Kalol Formation is the main reservoir in Lanwa field and houses the bulk of OIIP. The primary recovery of the field is about six percent.To enhance the recovery factor thermal EOR schemes are at different stages of implementation in the fields of heavy oil belt. The present paper deals with the generation of geological model for the pay sand KS-I and its relation and proximity to coal layers in the Lanwa field. Heterogeneity of KS-I pay sand has been defined by the fine scale Geocellular model. The thickness of the reservoir varies from 2-82 m with average porosity of 29%. The stratigraphic framework model involved the fine scale layering of KS-I pay sand into 277 layers from bottom. Processed petrophysical parameters derived from ELANPLUS were used in the well model. Attribute model shows the distribution of these properties on each cell of 100X100 m grid. The model clearly demonstrates the variation in reservoir properties throughout the field. The existence of coal and its proximity to the reservoir has greater impact on the thermal EOR process. The classification of coal distribution similarities and its proximity to the reservoir has provided an important additional parameter. Hence, the field has been divided into three sectors based on distribution of coal thickness and its proximity to KS-I paysand. The hazardous areas in relation to the presence of coal have clearly been identified to help the formulation of strategic plan for the thermal EOR process in Lanwa field