摘要：
In the process of developing offshore oilfield,the pipe string structure of the well in the sea is more complicated,compared to that on the land.There are usually multiple pipe string structure,such as tubing,casing and screen.In order to avoid the impact on the measurement results,we usually start carbon-oxygen ratio logging work after closing the well in 48 hours,which can ensure that the fluid in the pipe string is sufficiently static and stable.Due to the existence of the packer,there will be annulus fluid between the pipe string,which will have a great influence on later logging interpretation.When the fluid in the range of detection changes from water to oil,the calibration method is performed to be using the sensitivity difference between C/O and C/H.A new correction method is proposed to correct the carbon-oxygen ratio curve in this paper.When applying the carbon-oxygen ratio curve in correction to calculate the water saturation,we have found that the results match well with the open hole logging data.It provides a new idea for the correction of annulus fluid.%在海上油田开发过程中,由于海上的特殊情况导致井中的管柱结构比陆地复杂,通常存在多重管柱结构(套管、油管、筛管),然而在碳氧比测井过程中需要对目标井进行关井48 h后测量,使管柱中流体充分静止稳定,避免对测量结果带来影响.由于封隔器的存在导致在管柱之间会存在环空流体的情况,然而流体的分异性导致管柱中原本的流体会发生油水分层作用,这样会导致碳氧比测井时碳氧比曲线在油多的地方碳氧比值异常增大,形成环空流体影响,对后期解释带来很大的影响.因此提出一种新型校正方法,即当探测范围中的流体由水变为油时,C/O和C/H二者的灵敏度差异来进行校正处理.将校正后的碳氧比曲线运用于含水饱和度的计算中,发现校正后结果与裸眼井资料相符程度较高,应用效果较好,为环空流体校正提供了一种全新的思路.
