Authors:
Zhiqiang Li
;
Xinghai Gui
;
Zhiqiang Yang
;
Chen Li
;
Junyi Li
and
Yongli Ji
Affiliation:
The 22nd Research Institute of China Electronics Technology Group Corporation, China
Keyword(s):
Array dielectric logging tool, lateral wave, finite-element, detecting depth, vertical resolution, thin interbed layer
Abstract:
Dielectric logging is an important tool in geophysical exploration. For formation with fresh water and where water salinity is unknown, it has good performance in distinguishing oil and water layers. This paper presents the calculation of electromagnetic field in layered medium by analytical formulas and by finite element method, and compares the accuracy of these two methods. The inversion charts, measurements’ depth and vertical resolution are researched. The responses of thin layers and thin interbed layers are also discussed. The designed array dielectric logging tool has been tested in practical wells. Research results show that the analytical formulas are fast and effective for calculating apparatus response of layered medium, and also for retrieving dielectric constant and resistivity. For the array dielectric logging tool, the depth of investigation is 10-25cm, and the vertical resolution is 4cm. The array dielectric logging tool has been tested in XX oil field. For freshwate
r formation with high resistivity, the measured dielectric constant is about 10 in oil layers, and the measured dielectric constant is about 20 in water layers. The device could distinguish oil and water layers obviously, which offer additional method for formation evaluation.
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