增长曲线的分类与优选

Classif ication and Optimization of Increase curves

俞启泰

Yu Qitai

中国石油天然气集团公司石油勘探开发科学研究院

Scientific Research Institute of Petroleum Exploration and Development ,CNPC ,Beijing 100083 , P. R. China

对提出的用于预测油田开发指标的增长曲线进行了分类,根据曲线中常数的数目和含有的bt 和tb 项以及对应( tQ_t) _max和Q_tmax的准数,将增长曲线分为4 种类型,并分别列出了它们的N_p～ t 、Q_t～ t 、(N_p/N _Rmax )_{( tQt)max}准数、(Q_t/N _Rmax) _Qtmax
准数以及参数求取的关系式。通过对随机抽取的试样———庆祖集油田用上述增长曲线计算的相关系数R 、最大可采储量N _Rmax值、以及曲线初始产量Q_i 、(N _P/N _Rmax) _Qtmax准数的最大变化范围、参数求解的方便程度等5 方面的研究和分析,从中筛选出一种最优的增长曲线———3 常数b^t 型不定准数俞启泰增长曲线Ⅰ(3Y1 增长曲线) : N_p = N _Rmax(b^t - 1)/(b^t + a);而3 常数t^b 型定准数Weibull 增长曲线(3W 增长曲线) : N_p = N _Rmax (1 - e ^{- tb/ a}) ,可作为当(N_p/N _Rmax) _Qtmax> 0. 5 时的补充曲线。对增长曲线的研究和应用表明,提出的增长曲线法是和递减曲线、水驱特征曲线法具有同等重要地位的一种新的油藏工程方法。

The proposed increase curves for predicting oil field development indexes have been classified. In terms of number of constants , term of containing bt or tb ,and criterion corresponding ( tQt) max and Qtmax , the increase curves are divided into four types : (1) the increase curves of bt type with non-fixing criterion and 3 constants ; ( 2) the increase curves of tb type with fixing criterion and 3 constants ; (3) the increase curves or bt type with non-fixing criterion and 4 constants ; (4) the increase curves of tb type with non-fixing criterion and 4 constant s. The relationships of Np -t , Qt-t , and Np NRmax ( tQ)tmax criterion , and Np NRmax Qtmax criterion ,and formulas for obtaining parameters of these increase curves are listed. According studies and analyses for calculating maximum recoverable reserves NRmax and correlation coefficient of a actual oilfield ,Qingzuji Oilfield ,sampled randomly by using above-mentioned increase curves and their initial production Qi , maximum range of NpNRmax Qtmax criterion and easy level obtaining parameters ,the best increase curve , Yu Qitai increase curve of bt type with non-fixing criterion and 3 constants ( 3Y1 increase curve) , Np = N Rmaxbt - 1bt + a, have been screended in them. And Weibull increase curve of tb type with fixing criterion and 3 constant s ( 3W increase curve) , Np = N Rmax (1 - e – t b/ a) ,can regard as a additional curve while NpNRmax Qtmax> 0. 5. Studies and application of increase curves show that the proposed increase curve method is a new reservoir engineering method as important as decline curve method and water drive curve method.