对谢尔卡切夫（Щелкачев）公式的推导及拓展

从宏观角度对谢尔卡切夫（Щелкачев）公式进行了推导,使其更具有理论上的意义。通过推导,不但得到谢尔卡切夫的原式,而且得到了在我国普遍应用的另外一个关于采收率与井网密度的关系式。井网密度是指每平方公里上所钻有的井数,而井控面积则是单井控制的面积。通过理论推导和实例验证,得到了采收率-井控面积关系式常数与采收率-井网密度关系式的常数并不相同的重要结论,而我国在实际应用中常把两者混淆。实例计算表明,利用谢尔卡切夫公式,可以评价加密井提高采收率的幅度。通过对谢尔卡切夫公式的拓展,提出了确定驱油效率、体积波及系数和采收率的实用拓展通式。

Derivation and extension for Selkachev Formula

The main purpose of the paper is to derive Selkachev Formula from macroscopic view,so as to give it more theoretical significance.By the derivation,not only Selkachev′s original formula is obtained,but also another formula,applied widely in our country,related to recovery efficiency and well spacing density is obtained.The so-called well spacing density refers to the number of drilled well within per square kilometer and the well control area is the area controlled by single well.Through the theoretical derivation and example verification,the relational expression of recovery ratio and well control area is gotten.Meanwhile,an important conclusion that the constants of the relational expression of recovery ratio and well spacing density are different is obtained,but they are usually confused in our country.Based on Selkachev Formula,the extent of EOR in infill well can be evaluated,and it is testified by the concrete application.Through the extension on Selkachev Formula,the methods to establish the displacement efficiency,volumetric sweep efficiency and recovery efficiency are also presented in the paper.