DEVICE FOR THERMAL WELL LOGGING Russian patent published in 2008 - IPC E21B47/06 G01K7/20 

FIELD: well survey, particularly to determine thermal properties of rock seams surrounding wells during well drilling or cased wells, as well as to detect technical conditions of wells during well operation and downhole equipment operation regimes.

SUBSTANCE: device comprises three identical heat-sensitive sensors arranged along well axis at predetermined locations and adapted to measure the second temperature difference, namely the first, the second and the third ones. Each heat-sensitive sensor includes four identical heat-sensitive resistors constituting heat-sensitive bridges. Heat-sensitive bridge unbalance difference is proportional to the second temperature difference. Unbalance sum is proportional to the first temperature difference. All heat-sensitive resistors are used to measure absolute temperature of probe receiving medium. The first temperature difference depends on constant temperature change along well bore and on local temperature change. The second temperature difference depends only on local temperature change.

EFFECT: increased fullness of temperature field recording and measurement accuracy.

2 dwg