Method to Measure Front End Loading FEL of Steam-Based Thermal Recovery Projects to Assess Impact of Reservoir Complexity, Uncertainty and Risk in Future Performance

Abstract

Abstract At early stages of front end loading (FEL) of steam-based thermal recovery projects, oil companies make critical strategic decisions with limited understanding on how reservoir complexity, uncertainty and risk could affect recovery and economic performance. A solution is to measure front end loading (FEL) and improving it to meet a minimum level of project definition for sound strategic decisions. This paper presents a method to measure FEL by combining complexity and definition rating indices that account for a) reservoir structural, stratigraphic, rock, fluid, energy, static and dynamic complexity and b) definition rating indices and completeness of wells and surface infrastructure. Causal maps guide the assessment of complexity, uncertainty and risk in CAPEX, OPEX and cycle time of typical projects. Sixty-eight factors in eight matrices provide complexity indices and twelve additional factors account for completeness and definition indices for wells and reservoir under static and dynamic conditions. Five hypothetical examples using actual field data from analogs, illustrate how the method works. A causal map describes cause and effect relationships of uncertainty and risk for typical ranges of CAPEX, OPEX and project cycle times which translate into probability of success (POS). Finally, general strategies provide guidelines to reduce uncertainties and mitigate risks. By measuring and improving FEL companies increase the probability of success by mitigating risks such as higher operational expenditures (OPEX) to meet demand of energy, higher capital expenditures (CAPEX) for oversized processing facilities, and deferred production due to failures caused by extreme operating conditions imposed by high temperature, high pressure and corrosive contaminants. This method confirms the benefits of measuring the level of definition of a project, which is a best practice used in aerospace, nuclear, chemical, and other complex industries. It also improves the level of inter-disciplinary communication typical of reservoir-well-surface systems in steam-based EOR projects.