利用蒙特卡洛方法评估多个勘探圈闭的策略

Strategies of assessing multiple exploration traps by means of Monte Carlo method

海外油气勘探项目风险性极高,建立一套科学完善的风险评估方法在勘探决策中至关重要。利用蒙特卡洛概率法创造性地构建了一套风险评估工具,并通过具体实例验证了该方法的可靠性和实用性。在面对多个勘探机会时,首先,利用该工具测算多个圈闭的成功概率、含风险概率资源量、期望价值,其次,分析成功概率的相关性、钻井顺序和钻井数量等3个关键因素对含风险概率资源量、成功概率、经济成功概率及期望价值的影响,最后,基于以上研究,进一步深入探讨最终投标决策的策略。研究结果表明,合理评估项目的期望价值是勘探投标环节中中标的关键,期望价值是成功价值和失败价值的综合体现,在最终决策点选择上,要综合考虑成功概率及失败价值的承受能力的影响,而不能一味寻求期望价值的最大化。

The risk of overseas oil and gas exploration projects is quite high, so it is crucial for exploration decision making to develop a set of scientific and complete risk assessment method. In this paper, a set of risk assessment method was innovatively constructed by using the Monte Carlo probability method, and its reliability and practicability were verified by means of specific examples. When there are multiple exploration opportunities, it is recommended to firstly estimate the success probability, resource extent with risk probability and expected moneytary value of multiple traps by using this newly established method, then analyze the effects of three key factors (i.e., success probability dependency, drilling sequence and well quantity) on resource extent with risk probability, success probability, economical success probability and expected moneytary value, and finally discuss deeply the strategies for the final bidding decision making. It is indicated that rational assessment on the project's expected moneytary value is the key to win the bid in the link of exploration bidding, and expected moneytary value is the comprehensive embodiment of success value and failure value. To select the final decision making point, it is necessary to consider the success probability and the effect of the affordability to failure value comprehensively, instead of blindly seeking to maximize the expected moneytary value.