摘要
柴达木盆地昆北地区储层的核磁共振测井孔隙度、岩心核磁共振孔隙度均低于岩心氦孔隙度,这种现象导致核磁共振测井的应用受到限制。通过对该研究区的横向弛豫时间、岩心铸体薄片、X衍射、重矿物研究,研究发现,核磁共振孔隙度偏低的主要原因是花岗岩、变质岩岩屑组分中存在大量顺磁性矿物(磁铁矿、赤铁矿、黄铁矿)。此时,横向弛豫时间分布转化的视孔径分布会发生畸变,将其与压汞孔径分布放在同一坐标轴中进行对比,找出二者之间的差异,并对差异部分进行补偿校正,即可重新组构核磁共振孔隙度曲线。
In the Kunbei area of the Qaidam basin,both the reservoir's and core's NMR log derived porosities are lower than the core's helium adsorbed porosity,leading to a restricted application of NMR logging. From study on transversal relaxation time, core's thin section,X diffraction and heavy minerals,it is found that the low porosity values derived from NMR log are mainly attributed to the significantly existence of paramagnetic minerals( magnetite,hematite and pyrite) in the detrital components of granite and metamorphic rock. In this case,the distribution of apparent pore size converted from distribution of transversal relaxation time will be distorted. The distribution of apparent pore size is compared with that derived from mercury injection in same coordinate axis to find,compensate and correct their difference,resulting in a re- organized NMR log derived porosity curve.
出处
《特种油气藏》
CAS
CSCD
北大核心
2014年第2期75-79,154,共5页
Special Oil & Gas Reservoirs
基金
中国石油天然气集团公司重大科技专项"柴达木盆地高原咸化湖盆油气藏测井评价技术攻关"(2011E-0305)
关键词
核磁共振
顺磁性
孔隙度
孔径分布
测井
柴达木盆地
Nuclear-magnetic resonance
paramagnetics
porosity
pore size distribution
logging
Qaidam basin
