发明名称 |
Interferometric means and method for accurate determination of fiberoptic well logging cable length |
摘要 |
A method and means for determining the amount of stretch in a well logging cable is disclosed. An optical fiber is run into a well with a logging cable and looped back to the surface. A second optical fiber of nominal length is maintained on the surface. A source of monochromatic light is passed through both fibers and recombined. As the well logging tool is raised and lowered in the wellbore, the number of interference fringes passing a fixed point is determined. The change in length of the optical fiber and, therefore, the cable will be equal to 1/2 the number of interference fringes passing a fixed point times the wavelength of light used. A precise determination of vertical location can then be made when this information is combined with information from a surface mounted odometer or encoder. This information further allows a precise determination of interval bulk density or other formation parameters in which it is important to know the depth of a tool.
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申请公布号 |
US4862424(A) |
申请公布日期 |
1989.08.29 |
申请号 |
US19880168217 |
申请日期 |
1988.03.15 |
申请人 |
CHEVRON RESEARCH COMPANY |
发明人 |
GRAEBNER, PETER;SIE, SWAN A.;ANGEHRN, JORG A. |
分类号 |
G01B11/04;G01B11/16 |
主分类号 |
G01B11/04 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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