Selection of Optimal Developing Strategy for A Group of Prospects in Termsof Geological Uncertainties and Infrastructure Constraints

摘要

The aim of this work is to create a tool that can help in making difficult investment decisions about thesequence and commissioning periods of new hydrocarbons fields,maximizing expected monetary valueand considering infrastructure constraints across a group of assets in terms geological uncertainties.The approach is to use probabilistic calculations and the modern portfolio theory,adapted to theconditions of the sphere of petroleum exploration and production.The goal of optimization is findinga strategy for new assets development that would have the maximum profit with minimal economic ortechnological risk.Measures of spread of a random variable(a.g.NPV)around its expected value are usedto measure an economic risk.Also,we propose a method of technological risk assessment,reflecting theprobability of hydrocarbon production in the required range.To obtain a probability distribution of theobjective function according to uncertainties in input data the stochastic Monte-Carlo simulation and"Latinhypercube"technique were used.Due to high dimensionality of the problem,heuristic optimization methodshave been used to solve the optimization task.A proxy model,based on the change in recoverable reserves volumes,starting production rates anddecline rates of hydrocarbon production for newly drilled wells is proposed in this paper.The modelcombined with the calculation of economic measures.The combination of simulation models with anoptimization algorithm allows to analyze a set of mathematical equations,containing a number of decisionvariables(e.g.,years of commissioning periods and/or the paces of drilling wells)and to determine theiroptimum values,leading to a solution with the desired ratios of the expected economic effect and risk value.As a result,the numerical experiment revealed that application of the portfolio optimization methods allowsto find new non-obvious solutions.The result of portfolio analysis is not a final product of project works,but,however,may be a basis for explanation of optimal development scenarios for a group of assets andcan help in finding non-obvious,but more effective investment and project decisions.A comparison of four heuristic algorithms in the single-criterion optimization problem was conducted.Conclusions about the effectiveness of the algorithms in terms of time and the fitness function values were made.The developed model and methods were used in task of searching the optimal development strategyfor a group of real hydrocarbons fields.