| 摘要 |
FIELD: physics, measurement. ^ SUBSTANCE: application: for nuclear-magnetic logging of oil and gas wells. Mostly flat-parallel dipole static field is generated near well with the help of at least one extended magnet made of conducting rare-earth material, with direction of magnetisation that passes perpendicular to longitudinal axis of magnet, and also flat-parallel dipole radio frequency field is generated, with the help of radio frequency coil, turns of which lie in planes parallel to plane of magnet magnetisation, but are shifted from magnet axis in direction perpendicular to above mentioned axis and direction of magnet magnetisation, besides, static field determines arched zone of survey near well adjacent to radio frequency coil, where value of static field intensity and frequency of radio frequency field satisfy conditions of nuclear-magnetic resonance appearance, as well as component of radio frequency field, orthogonal to static field, is mostly homogeneous, after that as a result of hydrogen nuclei excitation, signals of nuclear-magnetic resonance are received mainly from arched zone of survey, besides additionally with the help of short-circuited turns made of highly conducting material, one or several quadripole radio frequency fields directed so that in arched zone of survey they are summed with dipole field of radio frequency coil, and in the area opposite to arched zone of survey, also in the area of magnet and in the area located behind the magnet, dipole radio frequency field is compensated. ^ EFFECT: compensation of radio frequency field in conducting magnet and drilling fluid of well. ^ 5 cl, 7 dwg |
