Design and applications of drilling trajectory measurement instrumentation in an ultra-deep borehole based on a fiber-optic gyro
<p>The working environment in hot dry rock boreholes, encountered in deep geothermal investigation drilling and ultra-deep geological drilling (up to 5000 <span class="inline-formula">m</span>), is very difficult at the present stage. We have developed a drilli...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-03-01
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| Series: | Geoscientific Instrumentation, Methods and Data Systems |
| Online Access: | https://www.geosci-instrum-method-data-syst.net/9/79/2020/gi-9-79-2020.pdf |
| Summary: | <p>The working environment in hot dry rock boreholes, encountered in deep
geothermal investigation drilling and ultra-deep geological drilling
(up to 5000 <span class="inline-formula">m</span>), is very difficult at the present stage. We
have developed a drilling trajectory measuring instrumentation (DTMI),
which is based on the interference fiber-optic gyro (FOG). This can
work continuously, for 4 h, in an environment where the ambient
temperature does not exceed 270 <span class="inline-formula"><sup>∘</sup>C</span> and the pressure
does not exceed 120 <span class="inline-formula">MPa</span>. The DTMI is mainly divided into three
parts: an external confining tube, a metal vacuum flask, and a FOG
measurement probe. Here, we focus on the mechanical design, strength,
and pressure field simulation analysis for the external tube, the
structural design and temperature field simulation analysis for the
vacuum flask, and the FOG Shupe error analysis and compensation in the
temperature field. Finally, through the engineering applications of the
SK-2 east borehole of the China Continental Scientific Drilling
(CCSD) project and the geothermal well of Xingreguan-2, the data
measurements of the drilling trajectory were used to analyze the
stability of the DTMI. The instrument realizes long-duration, high-stability work in the process of making trajectory measurements in an
ultra-deep hole. The instrument has the characteristic of
anti-electromagnetic interference and enables work to be carried out
in the blind zone of existing technologies and instrumentation.
Therefore, DTMI has great potential in the promotion and development
of geological drilling technology.</p> |
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| ISSN: | 2193-0856 2193-0864 |