Exploration Insights September 2020 - Page 4

Comparing the Qualities of Petroleum Systems: A Holistic Approach 4 | Halliburton Landmark by: Owen E. Sutcliffe, Mike Treloar and Daniel Slidel Outcrop of the Late Jurassic black shales and sandstones in the Boulonnais, northern France. Despite having good potential due to favorable petroleum system e Sutcliffe. Conventional petroleum systems are complex geological entities. They comprise petroleum system elements and petroleum system processes. The elements originate, contain, and retain hydrocarbons within them and are represented by overburden, source rocks, reservoirs and cap rocks. The processes generate, migrate, trap and preserve hydrocarbons within the system (Figure 1). Due to the commercial importance of these systems, superlative terms are often used to describe individual components to enhance their perceived value. For example, source rocks are often referred to as “world class,” while the epithet “excellent” is commonly used to promote reservoirs. Such terminology fails to take into account the petroleum system as a whole and has the potential to cloud our understanding of the system and its true resource potential. We have defined a hierarchical, holistic, semiquantitative index, which compares the qualities of petroleum systems on an objective basis, through the application of a new schema (Figure 1). This schema provides a means of seeing past the often-misleading terminology applied to a particular aspect of a petroleum system and establishes a framework for analogue definition, while also helping to retain accumulated knowledge on the nature of these systems. IDENTIFYING PETROLEUM SYSTEMS In order to compare the quality and potential of petroleum systems across the globe, the schema treats proven and frontier petroleum systems similarly. However, the level of knowledge of the former is greater than that of the latter.