Notional Development Concept Screening using Probabilistic Workflow for Prospects & Greenfield Projects

Identification and screening of development concept options is one of the critical steps during early stage of field life cycle (exploration and appraisal phase). This requires comprehensive understanding of uncertainty range in field parameters that may impact the recovery factor and conventional workflows may take many weeks to quantify the impact of each parameter on ultimate recovery. The proposed probabilistic workflow has been automated through efficient use of open-server application to accelerate the screening for faster decision making. This methodology consists of nine (9) steps for identifying list of low/base/high development concepts for any prospect or greenfield. The detailed description of the 9 steps will be provided in the paper. In summary, Steps-1 & 2 focus on identifying the relevant subsurface data and defining the best technical estimate model. Step-3 outlines the selection of key parameters that have a significant impact on the recovery factor. Probabilistic distribution function is used in Step-4 to define range of recovery factor for the prospect. Three representative models are selected in Step-5 and estimated recovery factors are also compared against benchmark values in Step-6 to ensure forecasts and recovery factors are reasonable. From a range of development options identified in Step-7, notional economic model is set up for techno-economic evaluation of the likely development scenarios in Step-8. Previous 8 steps enable selection of optimal development cases in Step-9. Six (6) steps of this workflow have been automated through integration of OpenServer application with pre-defined well, tank and network models. An integrated user-friendly spreadsheet is used to list all the parameters, generate the scenarios, and present results. This has facilitated to evaluate all development concept options within a week of model setup. Application of probabilistic workflow in exploration prospects has facilitated an end-to-end uncertainty management from in-place volumes range to recovery factor estimation and finally leading to development concept screening. This workflow can be applied to sizeable and/or strategic prospects to provide a comprehensive informed decision making on the way forward for resource maturation. The proposed probabilistic methodology for prospect evaluation followed by an appropriate development concept is quite generic and can be easily applied across the exploration to development stages of oil and gas industry.