Research On Quantitative Risk Evaluation Model For Natural Gas Development Planning

Natural Gas Development Planning(NGDP)is a guideline developed by Oil Company.It is compiled based on systematic review of natural gas development history,precise evaluation of the current development situation,and scientific prediction of its future development trend.As a comprehensive,forward-looking guiding principle and action guide,NGDP aims to lead the natural gas business to a sound track of development.Since entering the new century,the natural gas industry in China has stepped into a fast developing stage.Therefore,in order to eliminate the risk of uncertainties existing in the planning process and make the natural gas development plan a better guide,it is urgent to carry out researches on new planning approach for the natural gas development and quantitative research on risk evaluation.Thus,a systematic research on the model for the quantitative risk evaluation of natural gas development planning is carried out.As a result,the following achievements have been gained.First of all,multiple methods are used to identify risks.The risks are classified into seven categories:resource scale,reservoir geology,plan deployment,economic benefit,technology level,pipeline capacity and market demand,and macro policy risk.Among them,the first two are objective risks and the rest five are decision-making risks.Secondly,in accordance with the characteristics of the natural gas development planning,production optimization model is developed.In this model,the bases for evaluating the production scale are the resource scale and reservoir geology.The restriction factors are four types of decision-making risks including technology level advancement,pipeline capacity and market demand,macro-policy,plan deployment.The objective of this model is to maximize the economic benefit.Thirdly,a probability simulation model for gas development planning is established,based on Monte Carlo method and the production optimization model.A comprehensive risk assessment matrix is built which classifies risks into four grades.Accordingly,two approaches are established for quantitative evaluation of risks:probability curve scanning method for objective risks and probability curve displacement method for evaluating decision-making risks.The case study demonstrates that the quantitative risk evaluation model can not only show the risk level of a natural gas development planning in an intuitive way,but also precisely screen out the main risk factors.Therefore,this model is able to provide scientific basis for making risk aversion measures and ensuring a smooth implementation of a natural gas development programme.