N_p型增长曲线预测油田开发指标的0.5准数及其应用

A 0.5 Criterion Numeral of a New N_p Type Increase Curve for Predicting Development Indexes and Its Application

提出了一种预测油田开发指标的新型的增长曲线，■，推导了这种增长曲线的以及RPR的计算公式。用图形研究了这种增长曲线的Q1～t关系的变化特点。根据研究发现了一个重要关系，即油田生产时间t与相应的产量Qt的乘积达到最大值（tQt）max时的累积产油量Np(tQt)max与最大可采储量NRmax的比值恒等于0．5即■称为■型增长曲线预测油田开发指标的0．5准数。提出了根据实际资料计算NRmax、b、a等参数的方法。双河油田的计算实例表明这种增长曲线实用性强，精度较高。

This paper presents a new increase curve,■, for predicting development indexes, and deduces the calculation formulas of Q1 ~ t,tm, Qtmax and RPR. The changing characteristics of the Qt ~ t relation of the iflerease curve are studied through the use of figures. It is discovered that when the product of production time (t) and production rate (Qt) reaches maximum value (tQtmax), the ratio of accumulative production (Np(tQt)max) and maximum recoverable reserves (Nrmax) identically equals to 0.5, i.e. ■,which is termed as the 0. 5 criterion numeral of the new increase curve Np for predicting development indexes. The methods for calculating parameters such as Nrmax, b and a with actual data are proposed. A calculation in thc Shuanghe oilfield shows that the new increase curve is practical and accurate.