Exploration Insights September 2020 | Page 8

8 | Halliburton Landmark Petroleum System Elements Petroleum System Processes Good Reservoir Poor Trap 0.63 0.38 Good Source 0.67 Good Preservation 0.61 Good Seal 0.63 Poor Migration 0.33 Good Elements 0.64 Fair Process 0.46 Fair Index 0.54 © 2020 Halliburton Figure 4> Chart revealing the qualities of a late Carboniferous, coal-charged petroleum system in the East Irish Sea Basin. Note the occurrence of good-quality petroleum system elements, but some poor-quality petroleum system processes. USES AND IMPACTS OF THE SCHEMA The schema defined above is a holistic way of appreciating the qualities of petroleum systems and their potential to retain hydrocarbons. Our approach provides a systematic evaluation of the factors that lead to the development of more efficient petroleum systems. As the scoring is not reliant on an assessment of the volume of proven hydrocarbons, it provides a method to compare the qualities of proven and frontier systems. An understanding of the quality of petroleum systems can be used to compare different petroleum systems within and between basins. Our schema is semi-quantitative and applied consistently, so the index can also be used to identify analogue petroleum systems. This can be achieved either by utilizing the holistic index score for the basin, or by selecting the qualities of individual petroleum system elements or processes. In the following sections, a number of use cases are discussed with respect to this schema, that are illustrated with images for upcoming updates to the PlayFinder dashboard. Highlighting High-Risk Petroleum Systems The schema can reveal quickly why some proven petroleum systems are less prolific than others. The Carboniferous petroleum systems of the East Irish Sea comprise good-quality, organic‐rich coals that form a proven source rock, which has the potential to charge good-quality, late Carboniferous paralic sandstones, or Permian to Triassic terrestrial successions. All of the petroleum system elements seem to have the appropriate qualities for the development of a good petroleum system; this translates into a favorable index score in these categories (Figure 4). However, the timing of hydrocarbon charge, relative to the development of traps, as well as several episodes of uplift, have reduced the ability of the petroleum system to preserve hydrocarbons. Therefore, the index scores for the processes associated with this petroleum system are less favorable. This in turn affects the overall score of this petroleum system. In this