Building a dataset of offshore oil and gas extraction platforms from satellite data (2017–2023)
Abstract. Accurate information on the location and operational status of offshore oil and gas platforms (OOGPs) is important to inform decision-making by various stakeholders and to evaluate the environmental impacts of OOGPs. However, existing OOGP databases are often incomplete or outdated data. In this work, we use satellite data and the Google Earth Engine (GEE) platform to construct a new database of OOGPs for six major offshore oil and gas basins in the world between 2017 and 2023. We use synthetic aperture radar (SAR) images from the Sentinel-1 satellite mission to detect OOGP candidates due to its high sensitivity to OOGPs, dense spatio-temporal sampling, and global coverage. Our main processing steps comprise the detection of OOGP candidates using monthly averages of SAR images and the removal of noise and false positive objects from annual image composites. With the resulting dataset of OOGPs, we map the spatiotemporal distribution of OOGPs in the study regions and analyze platform status after the post-processing of the platform targets. Using these methods, we identified a total of 5,358 OOGPs distributed in six offshore basins: the Gulf of Mexico (GoM) (1,593), Persian Gulf (PG) (1,437), North Sea (440), Caspian Sea (CS) (794), Gulf of Guinea (460), and Gulf of Thailand (634). An independent validation dataset was used to evaluate the performance of the detection algorithm, which achieved an extraction accuracy of 98 %. This OOGPs dataset substantially enhances and complements the existing offshore platform database in terms of spatial and temporal coverage. From our analysis of this OOGP dataset, we observed that offshore platform activity has declined in regions like the GoM due to infrastructure aging and policy shifts, while it has expanded in the PG and CS, reflecting ongoing offshore development. These different regional trends highlight the need for targeted environmental oversight and region-specific mitigation strategies.
Thanks for this work, try to develop a robust algorithm to generate global offshore oil and gas datasets from satellite observations. The methodology and results look reliable and reasonable. I have several comments for your reference.
1. Fig. 3, why do you only use Sentinel-2 satellite imagers during Jan-Mar for OOGP generation?
2. L155-160, the FIRMS with 1-km spatial resolution, Near-real time frequency was used to identify platform activity status. This is an interesting point and skillful solution. The key challenge is how to address the discrepancy in spatiotemporal resolutions between this fire data and Sentinel-1/2 data (with 10-60 m resolution). Please add more details on this point. For example, how is proximity defined in the proposed approach?
3. L160, as mentioned above, FIRMS has a different spatiotemporal resolution from the primary satellite data (Sentinel-1/2). Please clarify this point.
4. Eq.(1), although two local examples are given to demonstrate the rationale regarding the BCmax threshold of -20db, an adaptive threshold like Eq. (2) is more reliable.
5. Fig. 10, how can we control the effect of the uncertainty in satellite data and algorithm (like threshold selection) on these temporal variations?