Assessment of Hydrocarbon Production Induced Surface Deformation over Inglewood oilfield, Los Angeles

Abstract. This study investigates surface deformation in the Inglewood oilfield using Sentinel-1 InSAR time-series analysis and its relationship with reservoir fluid dynamics. A total of 491 SAR images acquired between January 2020 and October 2025 were processed to derive line-of-sight (LOS) deformation from ascending and descending geometries. The results reveal a low-magnitude deformation field (< ±2 cm/year) characterized by localized subsidence–uplift patterns associated with hydrocarbon production. Decomposition of LOS measurements indicate predominantly vertical motion, with uplift and subsidence rates of up to +0.8 cm/year and −1.6 cm/year, respectively, while horizontal displacements remain minor (≤ ±1.0 cm/year).

To assess spatial variability, the study area was subdivided into three localized high-deformation zones, within which the relationship between reservoir fluid balance and surface deformation was evaluated. The results show that deformation is closely linked to fluid balance, although the strength of this relationship varies between zones. In Zone 3, a strong correlation (r ≈ 0.75) is observed between cumulative net fluid balance and uplift. Zone 1 exhibits a delayed response, with peak correlation (r ≈ 0.88) at a lag of approximately 5–6 months. In contrast, Zone 2 shows weaker coupling (r ≈ 0.42) despite exhibiting the highest subsidence, suggesting the influence of geological heterogeneity, structural controls, and additional wells not included in the analysis. These findings demonstrate the capability of InSAR to detect subtle deformation and provide valuable insights into reservoir processes.