Petroleum Science >2013, Issue 1: 50-54 DOI: https://doi.org/10.1007/s12182-013-0248-7
Genesis of the high gamma sandstone of the Yanchang Formation in the Ordos Basin, China Open Access
文章信息
作者：Liu Huaqing,Li Xiangbo,Liao Jianbo and Liu Xianyang
作者单位：
Research Institute of Petroleum Exploration and Development–Northwest, PetroChina, Lanzhou, Gansu 730020, China;Research Institute of Petroleum Exploration and Development–Northwest, PetroChina, Lanzhou, Gansu 730020, China;Research Institute of Petroleum Exploration and Development–Northwest, PetroChina, Lanzhou, Gansu 730020, China;Research Institute of Exploration and Development, Changqing Oilfield Company, PetroChina, Xi’an, Shaanxi 710021,China
投稿时间：2011-11-07
引用方式：Liu, H., Li, X., Liao, J. et al. Pet. Sci. (2013) 10: 50. https://doi.org/10.1007/s12182-013-0248-7
文章摘要
Recently, more attention has been paid on the high gamma sandstone reservoirs of
the Yanchang Formation in the Ordos Basin, China. These high gamma sandstones have logging
characteristics different from conventional sandstones, which influences the identification of sandstone
reservoirs. Zhang et al (2010) proposed that the high gamma sandstones of the Yanchang Formation
might be the result of re-deposition of homochronous sedimentary tuffs or previous tuffs as a part of the
sandstone. However, we present a different viewpoint: 1) few tuffs or tuff debris have been found in the
high gamma sandstones of the Yanchang Formation; 2) high gamma (or high Th content) sandstones
of Yanchang Formation are not related to either clay minerals or feldspar; 3) the heavy minerals in the
sandstone reservoirs of the Yanchang Formation are dominated by zircon, which is characterized by
abnormally high Th and U contents, up to 2,163 ppm and 1,362 ppm, respectively. This is sufficient
to explain the high gamma anomaly. The conclusion is that the high gamma value of the Yanchang
Formation sandstones might be caused by zircon with high Th and U contents in sandstones rather than
from the tuff components.
the Yanchang Formation in the Ordos Basin, China. These high gamma sandstones have logging
characteristics different from conventional sandstones, which influences the identification of sandstone
reservoirs. Zhang et al (2010) proposed that the high gamma sandstones of the Yanchang Formation
might be the result of re-deposition of homochronous sedimentary tuffs or previous tuffs as a part of the
sandstone. However, we present a different viewpoint: 1) few tuffs or tuff debris have been found in the
high gamma sandstones of the Yanchang Formation; 2) high gamma (or high Th content) sandstones
of Yanchang Formation are not related to either clay minerals or feldspar; 3) the heavy minerals in the
sandstone reservoirs of the Yanchang Formation are dominated by zircon, which is characterized by
abnormally high Th and U contents, up to 2,163 ppm and 1,362 ppm, respectively. This is sufficient
to explain the high gamma anomaly. The conclusion is that the high gamma value of the Yanchang
Formation sandstones might be caused by zircon with high Th and U contents in sandstones rather than
from the tuff components.
关键词
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High gamma sandstones, reservoir, zircon, Yanchang Formation, Ordos Basin