Re-Inventing Pressure Retained Core Acquisition for Advanced Reservoir Property Determination

Abstract

Abstract Innovation has always played a key role in past industry transition periods and helped to unlock the true potential of new technologies. For this reason, it is crucial to utilize and adapt these past experiences to effectively approach and tackle the challenges any operator is currently facing. The challenges range from understanding production behavior of reservoirs at any point of their lifecycle as well as CCS scenarios. Whenever injection is considered at any stage throughout secondary-, tertiary recovery stage or the general ‘re-utilization’ of the reservoir for storage respectively a thorough assessment is required. This increases the demand for sufficient data acquisition methods or workflows to overcome numerous shortcomings. With full bore core data being one of the key elements for ground truthing any data set used for reservoir modelling and project decision making (Saucier et al. 2022), the conventional methods utilized to acquire these core samples have a variety of weaknesses. While these standard methods are well established, more advanced coring methods are required to provide more comprehensive datasets for reservoir description. The method discussed in this paper aims to address these demands by delivering a high-quality in-situ core sample which is then processed on-site and introduced to best-fit lab workflow. Different special methods in the field of core acquisition are compared and strengths and weaknesses provide the context for potential need for a large diameter pressure coring technology. How this technology directly helps operators to better understand their reservoirs in any of the above-mentioned reservoir scenarios will be explained by describing different exemplary fields of application. These descriptions range from more accurate saturation determination of ROZs in depleted formations to acquiring in-situ PVT data for recombination of fluid volumes in conventional reservoirs to actual OGIP and GOR measurements in unconventional reservoirs. With the ongoing shift in the oil-&gas industry, pressure coring technology also has a high potential to become an important tool in storage efficiency assessments in CO2 injection wells for CCS applications. The study outlines how pressure retained core samples can contribute to reduce uncertainties and improved datasets which are needed in cases where the design of reservoir models require comprehensive knowledge of the entire spectrum of reservoir data. The proposed best practices are backed up by findings from recent achievements as well description of field activities in different applications. The study aims for giving an overview on how pressure coring technology enhances the available toolbox for downhole data acquisition and how the technology brings added value to the industry in an environment when more stringent economics rely on more accurate data validation of any asset.