The purpose of this paper is to present a methodology to generate a Company's production forecast by applying probabilistic tools to consider uncertainties and their impact on the outcome. Those uncertainties are in the category of technical, operational, social and environmental variables.
By analysing the entire production process at a company level, it was noted that it was required a comprehensive tool for forecasting, defining priorities, goal settings, production system analysis, decision making and performance evaluation. A probabilistic methodology was outlined to take into account uncertainty and interdependence of variables from different order, such as technical (decline, initial rate for new wells, EOR response, workover results), operational (downtime, drilling schedule, access to remote locations, oil evacuation), social (external blockage) and environmental (licensing time and conditions). All these variables are included in the generation of multiple production scenarios using Monte Carlo simulation and probabilistic trees. The probabilistic workflow generates production forecasts starting from each single well up to the Company level. It uses as input the results from conventional tools like reservoir simulation, DCA, Nodal analysis, maintenance plans, failure statistics, etc.
The probabilistic methodology can be used as a management tool that allows defining allencompassing production targets and to focus efforts and resources on the topics that generate greater potential deviation on production behaviour. A key contribution is the capacity to perform sensitivities for the impact of each variable and visualize it as a tornado analysis to define priorities and action plans that are reflected in Team and individual goals throughout the Balance Score Card methodology. As a result, this probabilistic methodology notably contributes to reach the production and unit operating cost target.
This methodology has been applied and improved during 3 years to make it more automatic, to assess risks, to link it to action plans and to combine it with other planning tools such us budgeting, oil transport and sales forecast.