The Detection Characteristics of a High Resolution Resistivity
Imaging
Instrument while Drilling
Abstract
Focusing on the problem of low distribution of circumferential
imaging
electrodes in existing resistivity
imaging
instruments while drilling, a new instrument
imaging
electrode distribution scheme was designed. The new instrument arranges 8 circular
imaging
electrodes in the circumferential direction. They are placed in 2 rows in the longitudinal direction, and each row of
imaging
electrodes has different diameters. In this configuration, it is possible that it can not only perform full wellbore coverage scan
imaging
during composite drilling, but also obtain the
borehole
images of 8 sectors with fixed orientation during slide drilling. Taking that into consideration, the complex horizontal layered strata, strata with circumferential anomalous bodies and horizontal well stratigraphic models were established, and analyzed the logging response and laws of the instrument in different stratigraphic models by using finite element method. The analysis results showed that this instrument had good longitudinal resolution, the longitudinal resolution of the
imaging
electrode was equivalent to its diameter, which could identify the azimuthal strata with high resistivity accurately; the horizontal well strata interface had different effects on the various orientation measurements of this instrument. Further, the response of lateral measurement mode at the strata interface was similar to that of cable lateral logging. The instrument scheme has good applicability in complex strata, and in the future, the research results could be used to guide instrument development and data interpretation.
2019 AAPG Datapages/Search and Discovery Article #130007 © 2019 Petroleum Drilling Techniques, Issue 2, 2019