LI Xue-sen 1, YANG Xiao-min 2, XU Xing-yu 1
(1. School of Earth Science, Guilin University of Technology, Guilin 541004, China;
2. Gudao Oil Production Plant, Shengli Oilfield, Dongying 257000, China)
Abstract: A total of 22 specimens for thermomagnetic analysis and identification of magnetic minerals were collected from the Cenozoic clastic reservoir rocks in Gunan Sag in the Bohaiwan Basin. Magnetic minerals and their assemblages in clastic reservoir rock specimens can be divided into three types: magnetite, goethite-pyrrhotite-magnetite, hematite-magnetite. Magnetic carriers in the rocks are closely related to lithology and have no obvious correlation with hydrocarbon saturation. Hydrocarbons have a certain influence upon thermomagnetic behavior of sedimentary magnetite in the clastic rocks. Heated in an argon environment, the Hopkinson peak of magnetite in the oily specimens is low and wide. In the cooling curve, the reappearance of magnetite is not obvious. The hydrocarbon emplacement, magnetic minerals and their assemblages in clastic reservoir rocks do not significantly change. Authigenic magnetite related to hydrocarbon fluids migration and accumulation is not widespread in the oily reservoir rocks.
Key words: magnetic susceptibility-temperature curve; thermal demagnetization; saturation isothermal remanent magnetization; clastic reservoir rock; Gunan Sag
E-mail：lixuesen2000@sina.com
ACTA MINERALOGICA SINICA Vol. 34, No. 4, 2014, Page 599-606
