Petrophysical Properties Distribution in The Framework of Electrofacies for Khasib Formation in Nasiriya Field, South of Iraq
Abstract
Determining petrophysical properties remains a paramount concern for oil companies, encompassing crucial properties such as porosity, permeability, and water saturation. Constructing accurate models requires an in-depth understanding of sedimentary facies within reservoirs. Despite the challenge posed by the absence of core samples, this study integrates fifteen well logs, borehole data, and seismic maps of the Late Turonian-Early Coniacian Khasib Formation from Nasiriya Oilfield, south of Iraq. The Khasib Formation is grouped into electrofacies by the integration of cluster analysis technique provided by Geology software using well logs and the borehole data. Electrofacies models are constrained using Petrel software. The porosity and water saturation models were built based on the electrofacies models. The property modeling including electrofacies, effective porosity and water saturation is stochastically distributed within the constructed 3D grid using Truncated Gaussian and Sequential Gaussian Simulation algorithms. Five different electrofacies (shale, marly limestone, argillaceous limestone, chalky limestone, and porous limestone) are recognized. The Khasib Formation is subdivided into 5 zones (A-E). The zone (Khasib E) is promising, and accumulates a considerable amount of oil with higher porosity and lower water saturation in the northwestern part of the field compared to the southeastern part. The area between the wells Ns-14, Ns-15, Ns-16 and Ns-18 can be the targeted area for production. Zones A and B are water-bearing, and they can be used for water injection purposes. This electrofacies-driven approach provides a detailed and accurate understanding of hydrocarbon accumulation and subsurface reservoir heterogeneity, offering valuable insights for Oilfield operations.
