RCX reduced risks while obtaining fluid samples in North Sea HP/HT well
A major operator in the North Sea needed to obtain pressure data and samples from a high-pressure/high-temperature (HP/HT) well. This would be their first attempt at taking a single-phase sample at a projected temperature above the standard rating of 350°F.
The Reservoir Characterization eXplorer™ (RCX™ ) system from Baker Hughes, a GE company (BHGE), had not been used in the field at such high temperatures before. However, it had been tested at the Houston Technology Center and handled 395° F for six hours, which was a significant upgrade from its initial testing of 375° F for 20 hours. Based on the new test data, the BHGE RCX service was selected for the sampling operation—a critical component of the wireline operation. During the sampling, the RCX tool recorded hydrostatic pressures well above 17,000 psi and temperatures in excess of 388° F.
BHGE used sample tanks with nitrogen charge pressure compensation to maintain single-phase integrity and operated three successful sampling stations that collected pressure and formation fluid samples. However, due to the extreme temperature, optical density/spectrometer data was unavailable. Since the operation had a restricted volume permitted in the wellbore, tracking hydrocarbons entering the wellbore was necessary. A near-wellbore simulator model helped determine the amount of volume needed for real-time cleanup forecasting.
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