钻探目标评价优选决策系统

钻探目标评价优选和部署决策是油气勘探工作关键环节之一，以勘探风险分析技术为基础，借鉴金融领域投资组合理论，结合我国圈闭评价技术标准，构建了钻探目标评价优选决策系统：①建立了以基础数据管理、成果数据管理、图形管理和文档管理为主要内容的综合性圈闭管理系统；②从钻探目标成藏过程出发，采用风险概率法，计算含油气概率，并根据资料置信程度建立了赋值原则和标准；同时，采用蒙特卡洛法模拟资源量分布，建立了圈闭群资源量计算方法以及计算参数合理性校验方法；最后，立足于勘探开发全过程，采用现金流法，重点关注油气发现风险和资源价值，针对圈闭和钻探目标分别提出预期收益计算方法；③采用“风险-价值”为核心的优选决策模型，建立了圈闭优选、预探井优选、预期收益-风险后价值排序以及投资组合优化和预探井部署方案油气储量规模预测方法，为预探部署提供依据。④建立了包括成藏规模对比、风险因素对比、含油气概率对比和失利因素分析4部分内容构成的钻后评估体系，首次引入了系统应用绩效评价，有利于加强预探项目的监督管理、提高评价人员的评价优选和部署决策水平。实际应用该系统，实现了不同地区、不同领域的钻探目标统一评价优选决策，为油公司规划编制和预探井部署提供了科学依据。

Evaluation,optimization and decision system for prospects to drill

Evaluation and selection of prospects to drill is one of the main tasks for the decision-makers of oil companies.Based on the principles of risk analysis and portfolio management, in combination with the Chinese technical criteria of prospect evaluation, a system of evaluation, optimization and decision has been built for prospects to drill.1)A management system of prospects with graphs, images, numbers, forms and texts integrated is established to perform basic data management, outcomes data management, graphics management and document management.2)Considering the geological process of petroleum accumulation and trapping, the discovery probability of hydrocarbon is defined.The general guidelines of evaluation are used to assign probability to each individual geological factor involved with respect to database reliability.At the same time, the distributions of resource amount of a prospect and a group of prospects are simulated and predicted by Monte Carlo, and three methods of reality checks have been provided to help evaluate those predictions.And then the economic characteristics of the resources of the prospects are valued by the conventional discounted cash-flow based on the whole process of petroleum exploration and production.3)'Risk analysis vs.economic value’ method is proposed for selection of the favorable prospects to drill, including prospect screening, wildcat well selecting, prospect ranking by expected return and risked value, and portfolio optimization.4) A post-drill assessment system is set up to monitor the wildcat drilling projects and improve the predictive performance, which consists of four parts: comparison between pre-and post-drill estimates of resource/reserve, comparison between predictive and actual results of key geological factors, calibration of hydrocarbon probability and analysis of the causes for the failure.This system has been successfully applied to decision-making of wildcat drilling programs in different geologic provinces.