The Temperature 2 Pressure Probe (T2P): Technical Manual

1.9. TEMPERATURE EFFECTSIn previous tools, temperature effects have played a role in the reliability of data. The lowering of temperature isbelieved to result in altered electrical characteristics and known to induce mechanical shrinking. As a means ofunderstanding the specific temperature effects of the CDAQ a series of experiments were performed.The experiment was designed to mimic the downhole environment of the tool. Therefore, a constant pressure wasapplied to a transducer by a long tubing system. The tubing, the transducer, and the CDAQ were all placed in arefrigerated room for a period of 15 minutes as the temperature approached 5 °C. The assembly was then removedfrom the refrigerator and allowed to reach room temperature. Several other experiments were performed, but thisparticular example characterized real conditions most approximately. Results of that experiment are presented belowas Figure 12.As determination of the temperature dependence, a linear regression was performed on the tip temperature versusthe tip pressure. The tip pressure recorded a constant pressure, so any pressure changes should be a direct result ofthe temperature differences. The pressure dependence appears to very mild. It could easily be ignored and notsignificantly affect any data analysis.472546.52046Pressure [psi]45.54544.51510Temp. [deg. C]44543.5Pressure - Ch.1 (Tip)Pressure - Ch.2 (Shaft)Tip Temperature43000:00:00 00:02:53 00:05:46 00:08:38 00:11:31 00:14:24 00:17:17 00:20:10 00:23:02Elapsed TimeFigure 12: Data from Temperature ExperimentVersion 1.0 Page 2909/21/2012