测井技术2018，Vol.42Issue(6)：658-661,4.DOI:10.16489/j.issn.1004-1338.2018.06.009
地层各组分热中子宏观俘获截面Σ值的最优化确定
Optimization of Regional Formation Parameter-Σ and Its Applications
康晓泉 1伍东 1赵秀峰 1何志明 1卢炳文1
作者信息
- 1. 中国石油集团长城钻探工程公司国际测井公司, 北京 100101
- 折叠
摘要
Abstract
Due to the difference in hydrogen content and formation water salinity, the thermal neutron macro-capture cross section (Σ) of each component of the formation have a range of variation.When using PNN logging to quantitatively calculate the saturation behind the casing, the uncertainty ofΣcan cause a certain amount of error in the result.The traditional method for determining theΣis as follows:First, input theΣof matrix, and then calculate and read the correspondingΣaccording to the formula and the plate, but the actual application shows that the result residual is too large.Based on the study, it is found that the equations for calculatingΣare an overdetermined system of equations, so there must be an optimal solution for theΣ.Therefore, during the PNN logging interpretation, the normalized nonlinear least squares principle is used in this paper to optimizeΣ of each component.In addition, the paper also discusses the establishment of optimization equations, the determination of initial parameter value, constraints and the principle of selecting depth points.The application results show that theΣ obtained by this method can reflect the petrophysical characteristics in the study area, which provides a basis for more accurate calculation of the formation saturation behind the casing.This method can also be applied when other logging curves such as natural gamma, neutrons, etc.vary with the parameters of the area and the composition of the formation.关键词
测井解释/地层组分/Σ参数/最优化/套后饱和度Key words
log interpretation/formation composition/Σ/optimization/formation saturation behind casing分类
天文与地球科学引用本文复制引用
康晓泉,伍东,赵秀峰,何志明,卢炳文..地层各组分热中子宏观俘获截面Σ值的最优化确定[J].测井技术,2018,42(6):658-661,4.
