射孔油井产率比计算模型

本模型综合考试了各种射孔因素、地质因素和工程因素。首次提出了极限产率比的概念，作为衡量产率比范围的简单有效工具。以极限产率比为基础，构造不考虑污染、不考虑压实条件的产率比计算模型，然后由此出发，构造未射开污染区及射开污染区的模型。考虑到压实的影响，在模型中引入了压实修正系数；并利用有限元射孔模型确定有关系数。通过以上方法得到７种射孔格式的２１个公式，可以解决各种射孔条件及常用７种射孔格式的产率比计

CALCULATION MODEL FOR PRODUCTION RATIO OF PERFORATED OIL WELL

The affect of perforation factor to oil well production is an important technical and economic problem in oil field development. Perforation factors (perforation length, perforation radius, perforation density, depth of crushed zone, degree of crush), geological factors (drainage radius, heterogeneity) and engineering factors (radius of well, radius of demaged zone, degree of demage) are included in this model. The definition of limite production ratio is presented as a simple and effective tool to evaluate production ratio. The calculation model without damage and crush is constructed on the basis of limited production ratio. We also in troduce a modification factor to consider the affect of crushed zone. Regression constants are detendned by finite element simulation model. 21 formulas have been obtained by the approach and can calculate produc tion ratio under various perforation conditions and 7 perforation formats, to evaluate well damage and predict the effect of underbanlance penetration, so as to optimize perforation system. The model has been tested by practical oil well testing data and shows very high accuracy. Industrail software applying the model has been popularize in most China oil fields.