测井技术2025，Vol.49Issue(1)：88-96,129,10.DOI:10.16489/j.issn.1004-1338.2025.01.010
基于快中子散射截面的气层评价方法及其应用
Tight Gas Evaluation Method Based on Fast Neutron Cross Section and Its Applications
摘要
Abstract
The tight sandstone gas reservoir in a certain area of Shanxi Province is characterized by low porosity and low permeability.The relationship between pore structure,resistivity and gas and water is complex.The reservoir characteristics pose challenges to the traditional gas layer interpretation and evaluation methods mainly based on resistivity logging.Therefore,it is urgent to seek a gas layer evaluation method that is suitable for such complex reservoirs and well conditions.This paper is based on the small-diameter pulsed neutron saturation logging tool-reservoir evaluation tool(RET),and uses the Fast Neutron Cross Section(FNXS)method to evaluate gas layers..Based on the feature that FNXS is sensitive to gas but not to non-gas,the FNXS value characterization formula is obtained through Monte Carlo numerical simulation under complex pore structure conditions.The correctness of the FNXS characterization formula is verified in the standard calibration well,and the gas saturation of the reservoir is calculated.The accuracy of this method is verified through field gas testing.Meanwhile,through the data analysis of multiple wells in the block,the FNXS value characterization formula for mudstone correction suitable for this block is established,further improving the accuracy of gas saturation calculation and forming the preliminary gas layer evaluation standard for this block.Practice has proved that the FNXS method based on the RET instrument can quickly identify gas layers under complex formation and well conditions.After slime emendation,the FNXS value characterization is more accurate and the calculation of gas saturation is more precise.This research effectively guides the exploration and evaluation of tight gas in the study block.In-depth research on the FNXS method shows that this method can also be popularized and applied in conventional gas-bearing reservoirs.关键词
致密砂岩气/脉冲中子饱和度测井/快中子散射截面/气水评价/蒙特卡罗模拟Key words
tight sandstone gas/pulsed neutron saturation logging/fast neutron cross section/gas-water evaluation/Monte Carlo simulation引用本文复制引用
揭志军,马晓静,蔡文浙,刘世伟,石耀,邱飞,吕黎明,梁国武..基于快中子散射截面的气层评价方法及其应用[J].测井技术,2025,49(1):88-96,129,10.基金项目
中海油田服务股份有限公司科研项目"储层评价仪RET的工程化及应用"(E23215003) （E23215003）
