DOWNHOLE TEMPERATURE PROBE ASSEMBLY (VARIANTS) Russian patent published in 2007 - IPC E21B47/06 

FIELD: well survey, particularly geothermal well survey.

SUBSTANCE: temperature probe assembly comprises temperature sensors installed in upper or lower assembly part and uniformly distributed around a circle having radius r>R₃/2, where R₃ is probe assembly radius. Circle center coincides with probe assembly axis. Assembly also has safety lamp made as a pipe with orifices. Summary orifice area is not less than pipe cross-sectional area. The probe assembly may be provided with two centralizers arranged in upper and lower parts thereof. In some variants temperature sensor is arranged along assembly axis in upper or lower part thereof, probe assembly has safety lamp made as a pipe with orifices, wherein summary orifice area is not less than pipe cross-sectional area, and pressing device. The pressing device includes two springs arranged in upper and lower probe assembly parts. Temperature sensor is 1-2 mm under or over safety lamp end plane correspondingly. In other variants safety lamp has beveled end and is pressed to pipe string by short generator thereof. Probe assembly variants including temperature sensors and two centrators in upper and lower parts are also disclosed. The temperature sensors are arranged on each spring of upper centrator in upper part thereof or each spring of lower centrator in lower part thereof is provided with one temperature sensor spaced a distance from pipe string or production string axes. The distance is determined from equation. In just other variants probe assembly has centrators arranged in upper and lower parts thereof and temperature sensors carried by substrate formed of resilient material and arranged in lower probe assembly part between springs of lower centrator or in upper probe assembly part between upper centrator springs. Each spring is provided with limiting strip to restrict substrate and temperature sensor displacement with respect to probe assembly axis. Temperature sensors are located in upper or lower probe assembly parts in dependence of downhole instrument movement direction during well survey performance.

EFFECT: increased accuracy of continuous temperature measurement along generator defined by temperature sensor movement due to elimination of liquid mixing in front of temperature sensor.

12 cl, 7 dwg