一种利用测井曲线齿化率刻画河道的新方法

为了精细描述以河道微相为主的油气田储层展布,对河道微相刻画的精度要求日益增高。针对目前沉积微相刻画存在的问题和难点,提出一种利用测井曲线计算齿化率,以此来确定河道位置、高精度刻画河道的方法。齿化率采用测井三参数来表征,即齿的幅度、齿的分布密度和齿的分布频率。总体思路是首先计算测井三参数,然后赋予每个参数一定的权重系数,得出该测井曲线段的齿化率。根据齿化率的大小,分析该段测井位于河道的具体位置,最后精细刻画河道。该方法相对于传统的沉积相研究,在相边界的刻画精度方面有了明显的提高,达到了半定量—定量的精度。将该方法应用于鄂尔多斯盆地某气田的沉积微相研究的实践表明,齿化率技术能清晰刻画河道特征,为有利区优选及井位部署提供准确依据,其研究成果可直接应用于生产中。

Optimal rotor wear design in hypotrochoidal gear pump using genetic algorithm

The wear rate between the rotors of a hypotrochoidal gear pump is characterized.Using the knowledge of shape design on the rotors,the contact stresses without hydrodynamic effect between the rotor teeth were evaluated through the calculation of the Hertzian contact stress.Based on the above results and the sliding velocity between the rotors,a genetic algorithm (GA) was used as an optimization technique forminimizing the wear rate proportional factor (WRPF).The result shows that the wear rate or the WRPF can be reduced considerably,e.g.approximately 12.8%,throughout the optimization using GA.