运用核磁共振录井技术评价砂砾岩体储层

Using NMR mud logging technology to evaluation conglomerate reservoir

核磁共振录井技术是通过测量岩样内氢核的横向弛豫时间(T2)的大小及其分布,实现在现场及时准确地获取储层物性参数的一项技术。该技术的特点是对岩屑样品的分析独具特色,测量结果不受样品颗粒大小的影响,分析快速,一次分析可提供多项参数,且分析结果准确。研究证实,核磁T2分布与由毛管压力曲线得到的孔喉半径分布在反映岩石的孔隙结构方面具有一致性,弥补了岩心毛管压力曲线数据的不足,为核磁共振技术进行孔隙结构的定量评价提供了新的方法。通过寻找T2几何平均值与孔隙结构参数之间的关系,建立了适合东营北带储层岩石孔隙结构评价的定量关系式,从而实现了利用核磁共振录井资料对岩石孔隙结构进行定量和快速评价。在此研究的基础上,结合测试层核磁物性资料,建立了东营北带储层核磁录井评价标准,在实际应用中取得了较好的效果。该技术在储层快速评价、油气水层综合解释等方面发挥了重要作用,对油田勘探工作具有一定的指导意义。

NMR mud logging is a technique about which the reservoir physical property parameters can be acquired timely and accurately in well site by measuring transverse relaxation time（T2） and its size and distribution in hydrogen nucleus existed in the rock samples. The feature of NMR mud logging is that the measure result is not controlled by the effect of sample grain size, the analysis speed is quick and an analysis can provide many parameters and the analysis results are accurate. The study result proves that the pore throat radius distribution, obtained by the curves of NMR T2 distribution and capillary pressure, shows a compatibility in reflecting rock pore structure, which makes up the defect of core data of capillary pressure curve and provides a new method for evaluating the pore structure quantitatively by using the NMR technology. Through studying the relationship between T2 geometric average value and pore structure parameters, the quantitative relational expressions between them are established, which is suitable tbr the quantitative and quick evaluation of pore structure in the north steep slope of Dongying Sag by using the NMR mud logging data. Combined with the NMR physical property data of tested zone, the evaluation standard of NMR mud logging for the north steep slope of Dongying Sag is established. Good application result has been gotten. The technology has played an important role in the quick evaluation of reservoir and comprehensive interpretation of oil-gas-water zone. It has a guiding sense for petroleum exploration.