摘要
论述了在南海西部盆地高温超压储层中利用测井资料定性识别及定量评价气体类型时遇到的问题。储层中同时含有CH_4、CO_2以及地层水时,导致该类储层测井响应特征变化复杂,尤其是CO_2溶于水后形成的附加导电性变化规律不清晰,导致基于电阻率测井响应的评价方法对CO_2的定性识别和定量计算变得异常困难。为此,利用CH_4与CO_2在中子、密度测井响应存在的差异特征,构建一个经孔隙度、含气饱和度校正的识别参数(NDS-Sg),利用该参数可以对气体类型进行有效的定性识别;基于CH_4和CO_2在热中子扩散及减速方面的差异特征,首次采用中子测井长短源距计数率建立了气体组分定量计算模型。定性识别及定量计算结果与测试结果吻合良好,证实了方法的可靠性。
This paper discusses the problem of qualitative identification and quantitative evaluation of gas type by logging data in the high temperature and high pressure gas reservoir in the basin of the western South China Sea.Due to the coexistence of hydrocarbon,non-hydrocarbon and water,the formation logging response gets complicate,and especially the additional conductivity has no obvious regularity when CO_2 gas dissolved in water,making it very difficult to use the resistivity method for CO_2 qualitative identification and quantitative calculation.So,we can calculate the parameter of Neutron-density intersection of the unit gas-bearing porosity,using Neutron-density intersection curve corrected by porosity and gas-saturation,on the basis of differences in neutron and density logging response of hydrocarbon and non-hydrocarbon gas.This parameter can be used to qualitatively identify non-hydrocarbon and hydrocarbon gas.By using the data of long short source-distance and count-rate values of neutron logging which is corrected by standardized treatment and aqueous calibration,we can establish the numerical calculation model of CO_2 content,according to the differences in thermal reduction and diffusion caused by hydrocarbon and non-hydrocarbon gas.The calculated CO_2 content by this method is not quite different from the results of oil-testing and sampling,confirming the reliability of the quantitative calculation method of gas composition.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2016年第12期2200-2206,共7页
Natural Gas Geoscience
基金
国家"十三五"科技重大专项子课题"莺琼盆地高温高压天然气富集规律与勘探开发关键技术"(编号:2016ZX05024-005)资助
关键词
南海西部盆地
高温高压储层
CO2气体
中子计数率
定量评价
Western South China Sea Basin
HTHP reservoir
CO2
Count-rate values of neutron
Quantitative evaluation
