发明名称 |
Method and apparatus for determining changes in length of a well logging cable. |
摘要 |
<p>A method and apparatus for determining the amount of stretch in a well logging cable is disclosed. An optical fibre (10) is run into a well with a logging cable (11) and looped back to the surface. A second optical fibre (14) of nominal length is maintained on the surface. A beam of monochromatic light from a source (17) is split and passed through both fibres and recombined. As the well logging tool (1) is raised and lowered into the wellbore, the number of interference fringes passing a fixed point is determined. The change in length of the optical fibre and, therefore, the cable will be equal to 1/2 the number of interference fringes passing a fixed point times the wavelength of light is used. A precise determination of vertical location of the well logging tool (1) can then be made when this information is combined with information from a surface mounted length measurement device, such as an odometer. 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.</p> |
申请公布号 |
EP0251671(A2) |
申请公布日期 |
1988.01.07 |
申请号 |
EP19870305609 |
申请日期 |
1987.06.24 |
申请人 |
CHEVRON RESEARCH COMPANY |
发明人 |
GRAEBNER, PETER;SIE, SWAN A.;ANGEHRN, JORG A. |
分类号 |
E21B47/04;G01B11/04;G01B11/16 |
主分类号 |
E21B47/04 |
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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