Multidisciplinary Integrated Approach Unlocks Fracture-Characterization Ambiguity

Abstract

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 213771, “Unlocking Fracture-Characterization Ambiguity: A Multidisciplinary Integrated Approach,” by Ali Abughneej, Mohamed Al-Naqeeb, and Mohammed Al-Ostath, SPE, Kuwait Oil Company, et al. The paper has not been peer reviewed. _ Fracture systems play a significant role in production in the case of tight, low-porosity complex reservoirs. An exploration well in North Kuwait that targeted the Middle Marrat formation encountered uncertainty regarding reservoir compartments in an underexplored field, with minimal offset wells to properly evaluate its potential. A multidomain approach is proposed leveraging different types of expertise to tackle the petrophysical and geomechanical aspects of the fracture system governing the carbonate layer and assess its producibility and qualification for stimulation through hydraulic fracturing. Introduction A comprehensive study was performed on Well A targeting the Marrat formation, a tight, low-permeability carbonate Jurassic reservoir. During the last two decades, the operator has drilled many vertical and deviated wells through this formation. Hydrocarbon production from the closely spaced wells shows a major variation in flow rates, which has been attributed to the presence of uncharacterized fracture clusters as well as the limited understanding of reservoir compartmentalization. To address the challenges of production discrepancy, an innovative multidomain approach was proposed as an integrated solution in an attempt to understand the fracture systems governing the reservoir setting and its compartments and further assess their connectivity and extent to form a perspective on their possible contribution or hindrance to flow. An end-to-end comprehensive work flow was created combining the results of advanced formation evaluation, high-resolution borehole imaging, and state-of-the-art sonic imaging [the 3D far-field sonic (3DFFS) approach], followed by a fracture-stability analysis for the purposes of completion optimization and potential future hydraulic fracture design. Geological Setting Middle Marrat is targeted as the hydrocarbon-bearing zone, consisting of dolomitized oolitic grainstone to packstone facies, reflecting the high-energy inner-midramp shoal depositional environment.