A recently developed bottomhole circulating temperature (BHCT) memory recorder is capable of recording downhole temperatures during circulation before cementing, squeezing, or plugback operations. Conventional methods for determining downhole temperatures have primarily relied on (1) cooldown correlations obtained from published API circulating temperature schedules or (2) temperature measurements acquired during drilling and workover operations. In many cases, a temperature gradient may be estimated from temperature surveys performed in similar wells previously drilled and completed in the same field. Caution is necessary when relying on temperature data that may not provide evidence of temperature anomalies or changes in temperature gradient below some given depth. The capability of the BHCT recorder to obtain actual bottomhole circulating temperatures without delaying normal drilling operations provides essential information needed when designing cement slurries for critical primary cement jobs.
The temperature memory recorder can be tripped into the well with pipe or wireline and can be dropped down the drillstring or tubing. Retrieving can be accomplished by tripping the temperature gauge out with pipe or wireline/slickline equipped with a retrieving head. Temperature data obtained with BHCT recorders are representative of true bottomhole circulating temperatures and can provide an accurate assessment of downhole temperature conditions before critical cementing operations are performed.
This paper presents a brief description of the temperature recording gauge and describes methods and techniques used to investigate the effect of a horizontal wellbore on bottomhole circulating temperatures. Results obtained from four temperature memory recorders placed at varying depths in a horizontal well during various stages of completion are also presented.