Distributed Temperature Sensing Monitoring of Well Completion Processes in a CO2 Geological Storage Demonstration Site

Abstract

The Distributed Temperature Sensing (DTS) profiles obtained during well completion of a CO2 monitoring well were analyzed to characterize each well completion process in terms of temperature anomalies. Before analysis, we corrected the depth by redistributing the discrepancy, and then explored three temperature calibration methods. Consequently, we confirmed the depth discrepancy could be well corrected with conventional error redistribution techniques. Among three temperature calibration methods, the conventional method shows the best results. However, pointwise methods using heat coil or in-well divers also showed reliable accuracy, which allows them to be alternatives when the conventional method is not affordable. The DTS data revealed that each well completion processes can be characterized by their own distinctive temperature anomaly patterns. During gravel packing, the sand progression was monitorable with clear step-like temperature change due to the thermal bridge effect of sand. The DTS data during the cementing operation, also, clearly showed the progression up of the cement slurry and the exothermic reaction associated with curing of cement. During gas lift operations, we could observe the effect of casing transition as well as typical highly oscillating thermal response to gas lifting.

Special Issue “Fibre Optic Sensors for Structural and Geotechnical Monitoring”

“…Paper [5] reports an application of distributed temperature sensing to monitor the final construction phase and commissioning of wells serving a CO 2 geological storage. In the paper, offline data analysis is done adopting different temperature calibration methods and results are compared.…”

Protection and Installation of FBG Strain Sensor in Deep Boreholes for Subsurface Faults Behavior Monitoring

“…With the development of optical measuring and packaging technologies, the scope for the use of optical fiber sensors has been expanding to various application fields. In this regard, fiber Bragg grating (FBG) sensors and distributed temperature sensing (DTS) are being actively applied for slope stability monitoring in the geotechnical fields [ 1 , 2 , 3 , 4 ] and temperature monitoring in the geophysical fields [ 4 , 5 , 6 , 7 , 8 , 9 ], respectively. Recently, distributed acoustic sensing (DAS), among distributed optical fiber sensing (DOFS) technologies, has been actively investigated for seismic survey and passive monitoring, including earthquake and micro-seismic monitoring.…”

“…Owing to these advantages, FBG sensors have been applied to monitor ground deformation in the form of multiple FBG sensor arrays [ 7 , 8 ] and borehole sensors installed by attaching them to the outside [ 19 , 20 , 21 , 22 , 23 ] or inside [ 24 ] of a casing, and then coupled with formation by cementing [ 25 , 26 , 27 ].…”

Comparative Experimental Study of a High-Temperature Raman-Based Distributed Optical Fiber Sensor with Different Special Fibers

“…Distributed temperature sensors based on the spontaneous Raman effect have become widely used in oil and gas sectors in applications such as leak detection in oil wells and thermal control of power lines [1,2,3,4]. These sensors offer many advantages in comparison to standard discrete temperature sensors [5,6] including inherent immunity to electromagnetic fields and allowing remote, long distance temperature measurement in dangerous, radioactive and toxic environments [7,8].…”