Study of land subsidence induced by oil extraction in the Tengiz oilfield of Kazakhstan using radar interferometry (InSAR)

Abstract

Our studies focused on the assessment of the surface deformation velocities and cumulative
displacements at Tengiz Oilfield in Kazakhstan using the Small Baseline Subset remote sensing
technique followed by 3D and 2D decompositions and cosine corrections to derive vertical and
horizontal movements from line-of-sight (LOS) measurements. In the present research we
applied time-series of Sentinel-1 satellite images acquired during 2018-2020. All ground
deformation derivatives showed the continuous subsidence at the Tengiz oilfield with
increasing velocity. 3D and 2D decompositions of LOS measurements to vertical movement
showed that the Tengiz Oil Field 2018-2020 continuously subsided with the maximum annual
vertical deformation velocity around 70 mm. Based on the LOS measurements, the maximum
annual subsiding velocity was observed to be 60 mm. The results of the present research will
support operators of oil and gas fields and also other types of infrastructure to evaluate the
actual differences of InSAR ground deformation measurements against the required standards
and the precision of measurements depending on the operational needs, timeframes and
availability of radar imagery.