This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 206322, “Business-Oriented Reserves and Resource Management: Experiences From a Merger,” by Thies Dose, SPE, and Gunar Kachel, Wintershall Dea, prepared for the 2021 SPE Annual Technical Conference and Exhibition, Dubai, 21–23 September. The paper has not been peer reviewed. In May 2019, the merger between Wintershall and DEA Deutsche Erdoel was closed, which was the birth of Wintershall Dea (WD). A system for internal reporting of petroleum resources described in the paper provides a fit-for-purpose approach, such as a consistent interpretation of commerciality criteria or definition of resources subclasses. A systematic resource-control system is defined, focusing on internal review, external and internal audits, and synergetic use of project reviews. Merging Existing Resource Reporting Legacy Wintershall reported resources both according to the Petroleum Resources Management System (PRMS) and the Securities Exchange Commission. PRMS reserves subclasses were reported according to project maturity (i.e., On Production, Approved for Development, and Justified for Development). This classification illustrates the project status of assets within the portfolio. The conversion factor from gas to oil equivalent was 5,600 scf/BOE, accounting for a high fraction of caloric gas in the portfolio. The official reserves and resource reporting of the legacy company toward its stakeholders was based on internally estimated reserves and resources figures. This was backed up by regular external reserves and selected contingent resources (CR) audits for control and calibration of the reported numbers. Legacy DEA reported resources according to PRMS only. Reserves subclassification was based on reserves status (i.e., Developed Producing, Developed Nonproducing, and Undeveloped). This highlighted the differentiation according to operational and funding status (Fig. 1). DEA’s reserves reporting was directly taken from external reserve audits, whereas CR were compiled from internal estimates. Because the portfolios of both legacy companies were mixed with respect to petroleum products, results needed to be normalized based on BOE. For the sake of consistency, all gas resources from legacy DEA were reconverted to oil-equivalent standards of legacy Wintershall. To lay groundwork for the respective filing of documents, various 1P and 2P reserves information from audits executed by the legacy companies had to be aggregated to provide a reliable and consolidated database for investors.