Digital Rocks: Developing an Emerging Technology Through to a Proven Capability Deployed in the Business

Abstract

Abstract This paper describes the development of ‘Digital Rocks’ technology – in which high-resolution 3D image data is used in conjunction with advanced modeling and simulation methods to "measure" petrophysical rock properties – through to a proven capability that is sanctioned for use in the operating assets of a large, multinational oil company. Digital Rocks is a disruptive technology in that it can fundamentally alter how the industry measures the basic rock properties that are used to characterize reservoirs and help predict their performance. Whilst Digital Rocks has been the subject of a number of publications, these have been generally limited in scope, and focus on certain aspects of the underlying science, or alternatively, present a stand-alone example application. This paper describes the research and development process, summarizes the results of extensive field trials, and explains how application of this technology has produced value within the context of an established field development decision-making process. We describe the underlying philosophy motivating the specific research that has been undertaken, and more generally, the technology development process that included extensive verification and validation. The paper describes navigating through the ‘valley of death’ – which describes the intervening terrain between research & development and the industrial application of a proven technology – a key challenge for nearly all emerging technologies. Details of the required capabilities, including experimental x-ray micro-computed tomographic imaging, image processing, numerical simulation including high performance computing, and rock physics interpretation are described. The technology development described is specific to static rock properties, and its application to conventional oil and gas reservoirs (i.e. permeabilities of ~1 millidarcy or greater). The results of over a half-dozen field trials carried out across BP's portfolio are presented, including comparisons of image-based porosity and simulated permeability, formation factor, cementation exponent, resistivity index, saturation exponent, and capillary pressure with experimental data that have been obtained using traditional laboratory measurement techniques on core plugs. The field trials included over 100 plugs taken from cores from more than ten wells. Digital Rocks technology can improve evaluation of reservoir quality and quantification of hydrocarbons in place, and it can help inform the development of improved recovery methods. Key advantages include reducing the cycle time for appraisal and reducing uncertainty in subsurface description.