发明授权
- 专利标题: Temperature compensated magnetic field apparatus for NMR measurements
- 专利标题(中): 用于NMR测量的温度补偿磁场设备
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申请号: US09739468申请日: 2000-12-18
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公开(公告)号: US06577125B2公开(公告)日: 2003-06-10
- 发明人: Manfred G. Prammer , Peter Masak
- 申请人: Manfred G. Prammer , Peter Masak
- 主分类号: G01V300
- IPC分类号: G01V300
摘要:
An apparatus is disclosed for generating a magnetic field of high field strength, spatial uniformity and minimal drift of magnetic field intensity over a temperature range of about 0° C. to 175° C. This apparatus may be used in a standard modular logging tool for direct downhole NMR measurements of various parameters of fluid samples of geologic formations near the walls of a borehole. In one embodiment, the apparatus is composed of two tubular permanent magnets made of different magnetic materials with different magnetic temperature coefficients to provide temperature compensation. The apparatus preferably also utilizes a pressure barrel that surrounds the magnets and provides a return path for magnetic flux lines, thereby increasing flux density within the measurement volume.