摘要
海上油气钻探中广泛使用油基泥浆,但提高钻井效率的同时,油基泥浆侵入地层,造成核磁共振(NMR)测井T_(2)谱的响应特征出现“拖尾”现象,严重影响了储层识别和评价。通过分析油基泥浆侵入地层后核磁测井T_(2)谱响应特征,并结合高温高压下油基泥浆侵入岩心的核磁共振实验,详细分析了不同孔渗岩样中的T_(2)谱“拖尾”现象,提出了一种校正方法,通过对比油基泥浆侵入前后岩样T_(2)谱的“拖尾”特征,推导出校正因子,建立用于T_(2)谱的快速校正方法。结果表明,校正前后,核磁计算的孔隙度差异小;校正后的T_(2)谱较好压制了“拖尾”现象,且获取的核磁渗透率与岩心渗透率匹配程度更高,证明了该快速校正方法的可靠性和实用性。该研究为油基泥浆侵入环境下的核磁测井评价提供了方法支撑,助力储层识别和评价。
Oil-based mud has been widely used in offshore oil and gas drilling,improving drilling efficiency.However,its invasion into formations causes the Nuclear Magnetic Resonance(NMR)T_(2)spectra to exhibit a“tailing”effect,significantly affecting reservoir identification and evaluation.The T_(2)spectra response characteristics after oil-based mud invasion were analyzed,and high-temperature and high-pressure NMR experiments on invaded core samples were conducted to investigate the“tailing”effect in cores with different porosity and permeability.A correction method was proposed,in which a correction factor was derived by comparing the“tailing”characteristics of T_(2)spectra before and after invasion,establishing a rapid correction approach for T_(2)spectra.The results showed that the corrected T_(2)spectra effectively suppressed the“tailing”effect,with minimal changes in calculated porosity.Furthermore,the corrected NMR permeability matched the core-measured permeability more accurately,demonstrating the reliability and practicality of the proposed method.This study provides methodological support for NMR logging evaluation under oil-based mud invasion conditions,facilitating improved reservoir identification and evaluation.
作者
黄易聪
秦臻
张雪
张昕熠
HUANG Yicong;QIN Zhen;ZHANG XUE;ZHANG Xinyi(Jiangxi Engineering Technology Research Center of Nuclear Geoscience Data Science and System(East China University of Technology),330013,Nanchang,PRC;Hubei Subsurface Multi-Scale Imaging Key Laboratory,Institute of Geophysics and Geomatics,China University of Geosciences,430074,Wuhan,PRC)
出处
《江西科学》
2025年第2期243-252,共10页
Jiangxi Science
基金
国家自然科学基金项目(42364009,441804097)
江西省自然科学基金项目(20224BAB203044)
教育部产学合作协同育人项目(221001592090942)
江西省研究生创新专项资金项目(YC2023-S555)
东华理工大学研究生创新基金项目(DHYC-202313)。
关键词
油基泥浆
校正方法
核磁共振实验
核磁T2谱
oil-based mud
the rapid correction method
NMR experiment
NMR T2 spectra
