油气田剩余可采储量、剩余可采储采比和剩余可采程度的年度评价方法

剩余可采储量、剩余可采储采比和剩余可采程度是判断油气田当前开发形势的重要指标,是决策是否进行开发调整的重要基础,因而受到全球各石油公司的高度重视。根据中国行业标准,评价可采储量的方法主要包括水驱曲线法、产量递减法和预测模型法。水驱曲线法仅适用于水驱开发的油田,而产量递减法和预测模型法则适用于已经进入递减阶段的任何储集类型、驱动类型和开采方式的油气田。DeGolyer and MacNaughton和Ryder Scott两家评估公司对中国境内油气田的剩余经济可采储量进行年度储量资产价值评价所使用的方法是由美国证券交易委员会多部门团队提供的Arps指数递减的变异公式。利用适用于不同开发模式的广义指数递减法,推导得到了油气田年度经济可采储量、剩余经济可采储量、技术可采储量、剩余技术可采储量、剩余可采储采比和剩余可采程度的计算公式,并对DeGolyer and MacNaughton公司使用的变异指数递减法进行了说明和评价。通过8个油田实际应用结果表明,笔者提供的计算方法实用有效。

Annual evaluation methods for remaining recoverable reserves,remaining recoverable reserves-production ratio and remaining recoverable degree of oil and gas fields

Remaining recoverable reserves, remaining recoverable reserves-production ratio and remaining recoverable degree are key indices for judging the current development status of oil and gas fields and provide an important basis for determining whether to adjust the development scheme, thus attracting high attention from global oil companies. According to national industry standards, the main evaluation methods of recoverable reserves include waterflooding curve method, production decline method and forecast model method. The waterflooding curve method is only applied to waterflooding oilfields, while production decline method and forecast model method can be used for any oilfields of all reserving types, flooding types and production modes in the decline stage. DeGolyer and MacNaughton Company and Ryder Scott Company were hired to evaluate the annual reserves asset values of remaining economical recoverable reserves for all national oil and gas fields. The evaluation method they adopt is the variation formula of Arps exponential decline method proposed by the U.S. Securities and Exchange Commission multi-department team. In this study, the generalized exponential decline method applicable to different development modes is used to derive the calculation equations of annual economical recoverable reserves, remaining economical recoverable reserves, technical recoverable reserves, remaining technical recoverable reserves, remaining recoverable reserves-production ratio and remaining recoverable degree of oil and gas fields. In the meantime, the variant exponential decline method adopted by DeGolyer and MacNaughton Company was illustrated and evaluated. The calculation methods presented by the author were confirmed practical and effective in terms of actual application results in eight oilfields.