Deformation Monitoring and Primary Driving Factor Analysis in the Coastal Area of Liaohe Oilfield Utilizing MT-InSAR and PCA

Water injection and oil production often lead to significant surface deformations in oilfields. Such geological hazards are substantial potential threats to both the oilfield and its surrounding infrastructure. Liaohe oilfield is China’s largest production base for heavy and high-viscosity oil. It has a long history of surface deformation in its core production area near the Bohai Bay. Multitemporal synthetic aperture radar interferometry (MT-InSAR) offers long-term monitoring capabilities and has previously been used to monitor deformations in Liaohe oilfield. However, quantitative analysis of deformation-driving factors is less common in previous studies, and investigations are limited to data up until 2021. Continuous monitoring and analysis of deformation patterns and influencing factors in this region are of crucial practical importance. In this study, we acquired the latest long-term deformation data and the driving factors in Liaohe oilfield via MT-InSAR. For the first time, a quantitative analysis of deformation-driving factors was performed, and the ultra-long-term (from 1958 to 2023) deformation data with respect to Liaohe oilfield were collected and analyzed to interpret the deformation characteristics, variation tendency, and influencing factors. We employed 217 Sentinel-1A/B SAR images from 2019 to 2023 to calculate the deformation rates and cumulative deformations in this area. The results revealed three subsidence funnels and one uplift area, with deformation rates ranging from [−152, 41] mm/year and [−182, 51] mm/year (negative values indicating subsidence and positive values indicating uplift) for the ascending and descending datasets, respectively. Principal component analysis (PCA) was applied to the cumulative deformation sequence for extracting the primary components. The PCA results, groundwater data, and precipitation data were utilized for a quantitative analysis of primary deformation-driving factors. The analysis results indicate that the surface deformations exhibit a strongly linear trend mainly due to oilfield exploitation, coupled with slight variations related to precipitation and groundwater extraction. By integrating historical deformation information with the monitored results, the development process of the surface deformation was investigated and divided into six stages. This process was related to the oil energy demand, extraction techniques, and reservoir compaction phases. This study contributes to understanding the spatiotemporal evolution of surface deformation in the Liaohe oilfield and the driving factors, and it provides valuable insights for similar research in other oilfields.