用电测井或中子寿命测井单独测量含水饱和度SW时,因目的层地层水电导率σW或热中子俘获截面∑W不能从目的层直接测量而不得不使用由其他办法推算替代值,造成了SW的误差,在地层水性质多变时问题更加严重.用目的层电导率σt和俘获截面∑t关于SW、σW或∑W的2个表达式,再加上σW与∑W之间的关系式构成一个可解出3个未知数SW、σW和∑W的三元联立方程组.按此原理开发的组合测井系统只用自己采集的原始数据,就可以在岩性复杂水性多变的条件下,实时给出SW、σW和∑W值.针对思考提出了研究课题建议.%It is the common obstacle in measuring water saturation Sw with electric or neutron lifetime well logging separately that the conductivity σw and thermal neutron capture cross-section∑w of formation water can not be measured directly at target bed, so that their substitutes estimated with other methods have to be used. It causes error in Sw, and even worse in changeful formation water. An approach on Electric-Nuclear Integrated Info-Self-Consistent Saturation Well Logging is proposed, in which a set of simultaneous equations having 3 unknown variables (Sw, σw and ∑w) is constructed with 3 expressions, namely conductivity σt and capture cross-section ∑t of the target bed, as well as correlative relationship between σw and ∑w. The well logging system developed on the approach, just depending on original data acquired itself, could measure the Sw, σw and ∑w in real-time by well logging even in condition with complicated lithology and changeable formation water. Its technological foundation has been tamped by success in replacement of chemical radioactive source by controllable one, and integrated well logging system being perfect day by day. It has got practical applicable effectiveness first in LWD. Primary conditions of the approach have been furnished in China, but still needs colligated research of electric and nuclear well logging. Concerned research projects for the idea are proposed.
展开▼
