Surface Deformation Monitoring (environmental and production related)
Surface deformation (Source: TRE)
- Subsidence monitoring - Land motion relating to fault lines or other causes
- Subsidence monitoring - Reservoir management
- Subsidence monitoring - Infrastructure monitoring
- Surface Geology Mapping - Structural interpretation
- Logistics planning and operations - Facility siting, pipeline routing and roads development
- Surface and ground motion
Surface movement can be accurately determined by processing SAR imagery acquired over an area of interest with the same geometry using advanced interferometric techniques. Surface movement information is typically visualised using ground movement maps or in GIS systems, where movement due to oil & gas production (including related activities) or to natural phenomena can be identified and analysed.
Resulting movement maps can be used to determine the impact of reservoir production, enable efficient reservoir management and improve understanding of reservoir dynamics, for example: reservoir compartmentalisation, subsurface fluid dynamics and fault reactivation.
Surface movement is identified for the entire period of SAR acquisitions, where satellite imagery is tasked to acquire for specific periods (short- or long-term), depending on the requirements of the Client.
SAR imagery is processed at discrete intervals for the production of ground movement information and depending on the satellite(s) used, update maps of surface movement can be provided on a weekly, monthly or annual basis. Typical SAR acquisition repeat cycles are every 4 to 24 days.
Surface movement measurements are provided along the satellite’s line-of-sight and, with the availability of both ascending and descending geometry SAR datasets, in the vertical and horizontal directions.
Known restrictions / limitations
- Accuracy and density of measurements dependent on a number of factors, including the wavelength of SAR sensor and repeat time of the satellite
- North-south movement cannot be identified
- Processing for high-accuracy ground movement can be performed only after acquiring a minimum number of SAR images (approximately 15-20 SAR images with same geometry)
- No surface movement information achievable over water bodies
- Density of measurement points identified over vegetated / swampy areas decreases
- Surface movement is a combination of all active layer deformation contributions
Lifecycle stage and demand
Exploration & Development:
- Baseline mapping of natural ground movement pre-production phase and ground movement related to production activities for improved reservoir management
- Critical current ground movement information for the identification of stable ground to support effective and safe land seismic surveys and for the planning of infrastructure, pipelines, wellheads and area development
- Analyses of surface movement to provide information on subsurface features including compartmentalisation, fault reactivation, fluid dynamics, etc.
- Identification of stable ground for the safe and effective planning of ground surveys and infrastructure
- Surface subsidence / uplift associated directly with reservoir production can be determined and quantified. Resulting maps can be used to improve reservoir management.
- Ground movement over infrastructure, e.g. wellheads, pipelines, etc. can be monitored in order to identify potential stability issues
- Same as production. Once the well is closed, remediation monitoring will confirm the stabilisation of the site before transfer to regulator/Crown.
Geographic coverage and demand
Demand and coverage is globally onshore or on offshore platforms.
OTM:001 Identifying effect of fault reactivation
OTM:002 Tracking fluid migration in the subsurface
OTM:003 Subsidence from reservoir draw-down
OTM:004 Regulatory verification relating to injection of fracking fluids
OTM:005 Monitoring natural fault movement
OTM:006 Technical verification relation to injection of fracking fluids
OTM:007 Identify communication between producing zones
OTM:010 Monitoring ground movement along pipelines
OTM:011 Surface infrastructure movement relative to sub-surface
OTM:014 Forecasting sand dune migration
OTM:020 Tracking groundwater tables
OTM:051 Identification of fault lines
OTM:060 Forecasting landslide locations
HC:1105 Identify permafrost zone for data analysis
HC:2501 Characterization of surface/near-surface structural geological properties for infrastructure planning
HC:2504 Identification of slope instability
HC:2505 Identify geophysical properties of the subsurface
HC:3101 Baseline and monitoring of areas with active faults and subsidence
HC:3201 Assessment of infrastructure placement and effects to the surrounding environment
HC:3203 Management of surface impacts due to ground deformation from operations
HC:3204 Monitor stability of surface reservoirs such as settling ponds
HC:3302 Assessing ground deformation to support enhanced recovery operations
HC:3303 Monitoring effectiveness of steam assisted gravity drainage (SAGD) operations
HC:4201 Remediation and reclamation monitoring
HC:4208 Identification of groundwater table to reduce potential issues during seismic activity
HC:4301 Map and monitor induced seismic hazards
HC:5201 Monitoring assets for risk management
HC:5306 Assessing terrain stability for infrastructure planning in permafrost environments
Input data sources
Radar: VHR2, HR1, HR2
Spatial resolution and coverage
Spatial resolution: 20x5 m / 3x3 m / 1x1 m pixel size
Coverage: 250x150 km / 100x100 km / 40x40 km / 30x50 km / 10x10 km
Minimum Mapping Unit (MMU)
Related to pixel size of satellite imagery used. One ground measurement point can be identified for each pixel in satellite image.
Accuracy / constraints
Thematic accuracy: Ground movement can be determined to millimetre accuracy (with a sufficient number of SAR images)
Spatial accuracy: In ideal conditions, one measurement point is identified in each SAR image pixel
Accuracy assessment approach & quality control measures
MonteCarlo statistical approach
Frequency / timeliness
Observation frequency: Constrained by satellite repeat cycle, typically 4-24 days. Appropriate satellites can be chosen in terms of spatial and temporal resolution.
Timeliness of delivery: Depends on the requirements of the Client and processing required
Basic analysis can be performed quickly (24-48 hours) whilst integrated products require detailed analysis (2 weeks).
Delivery / output format
- Vector formats
- Raster formats (depending on client requirements)
- Geotiff or GIS shapefile (standard - any other OGC standard file formats)
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