Streamline Simulation for Geological Model Validation and Waterflood Pattern Management in the FM-1 Layer of the Mangala Field, Barmer Basin, Rajasthan, India

Abstract

Abstract The Mangala Field is located in the northern Barmer Basin of Rajasthan state, India. The basin is a Tertiary rift, predominantly consisting of Palaeocene-Eocene sediments. The Mangala Field was discovered in January 2004 and brought on production with hot water flooding in August 2009. The main reservoir units in the Mangala Field are the fluvial sandstones of the Fatehgarh Formation. The Fatehgarh Formation in the Mangala Field is subdivided into 5 reservoir layers termed FM1 (top) to FM5 (base). The lower part of the Fatehgarh Formation (FM3 to FM5) are dominated by well-connected sheet flood and braided channel sands, whilst the Upper Fatehgarh Formation (FM1 and FM2) is dominated by more sinuous, laterally migrating fluvial channel sands. The FM-1 unit hosts approximately half of the oil in place. A detailed fine layer geological model was built for the Mangala Field incorporating all relevant data from the field generated over the last couple of years. A set of 100 realizations of the geological model were generated. All of the realizations for FM-1 layer were simulated in a commercial streamline simulator using the available historical production data for FM-1 wells. The paper discusses the results from these multiple realization runs and the inputs given to the geological model which was used to improve the model further. These runs helped in identifying the areas where sand connectivity was low due to presence of some baffles or channel boundaries and needed improvement, to match fluid flow in the reservoir. After incorporating the PLT data into the dynamic model, the well wise water cut resembled the actual w/c and improved the confidence level on the geological model. The paper also discusses well allocation factor estimates for each producer and injector pair from the streamline simulation model for different injection patterns in FM-1. The well allocation factors helped in understanding the level of support each producer is getting from the nearby injectors