应用逐步回归建立岩石孔隙度图版

油层岩石具有在其空隙中储存流体(油、气、水)的性质,称为油层的孔隙性。油层的孔隙性是油层最重要的物理性质之一,油层孔隙性的好坏标志着油层本身储油能力的大小。为了衡量油层孔隙性好坏,把岩石的孔隙度作为油层孔隙性的定量指标。岩石的孔隙度是指岩石中孔隙的容积与该岩石体积的比值(以百分数表示)。

THE USE OF STEPWISE REGRESSION TO MAKE UP MAP BOARD OF LITHOLOGIC POROSITY

This paper describes the application of stepwise regression analysis to calculate porosity of rocks from well log data.If we assume: the porosity (φ) is dependent variable, the acoustic velocity time difference (△t), nature Gamma (GR) and nature electrical potential (a) are three independent variables. The binomial expansion is used in the calculated procedure, and two new independent variables are added on the basis of explanatory theory and practical experience of well log, through stepwise calculation, we get the following equation:Thus, using this approximation expression mentioned above, we may make up quantitative explanatory map board of porosity of rocks.Interior , interpolation accuracy joined in statistical samples is 93.8%.Average predictive accuracy appllied to a porosity map board to the oil field is91%.