发明名称 |
Doubly-compensated dual-detector density logging apparatus |
摘要 |
A technique for determining the density of an earth formation with a logging sonde including a gamma ray source and two gamma ray detectors spaced at different distances from the source is disclosed. The count rate of the short-spaced detector is measured in two energy ranges covering back-scattered gamma rays which have undergone relatively low and high attenuations respectively. A first density correction is determined from the difference between the apparent density derived from the count rate of the long-spaced detector and the density derived from the count rate of the short-spaced detector in the energy range covering gamma rays with relatively low attenuation. A second density correction is determined from the difference between the densities derived from the two short-spaced detectors' count rates. These two density corrections are added to the apparent density to give the true formation density.
|
申请公布号 |
US4048495(A) |
申请公布日期 |
1977.09.13 |
申请号 |
US19760649865 |
申请日期 |
1976.01.16 |
申请人 |
SCHLUMBERGER TECHNOLOGY CORPORATION |
发明人 |
ELLIS, DARWIN V. |
分类号 |
G01V5/04;G01N23/203;G01V5/12;(IPC1-7):G01V5/00 |
主分类号 |
G01V5/04 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|