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  • Product Sheet: Seismic Logistics

Seismic logistics operation map & Base camp mapping

 

Seismic logistics risk map (Source: WesternGeco)

PRODUCT DESCRIPTION

Category

Component products

Integrated Product

 

  • Vegetation type, forest type
  • Hydrological network & catchment/watershed area
  • Wet areas (incl. ephemeral)
  • Camp maps
  • Oil field infrastructure
  • Cleared/disturbed land
  • Linear cleared/disturbed land
  • Lithology features
  • Geomorphology map
  • Slope stability (geo-hazards, slope face creep); slope enhanced geomorphology map
  • Soft ground
  • Terrain roughness
  • Elevation
  • Slope, curvature, aspect

 

Uses

  • Seismic Planning - Areas of poor coupling
  • Seismic Planning - Identification of adverse terrain for trafficability
  • Seismic Planning - Identifying environmentally sensitive areas
  • Surface Geology Mapping - Terrain evaluation and geo-morphology characterization
  • Environmental Monitoring – Natural hazard risk analysis
  • Logistics Planning and Operations - Baseline mapping of terrain and infrastructure
  • Logistics Planning and Operations – Support to surveying crews
  • Lithology, geology and structural properties of the near surface

Geo-information requirements

  • Precision ortho-images
  • Terrain information
  • Topographic Information
  • Detailed land use information
  • Detailed land cover information
  • Distribution and status of infrastructure
  • Distribution and status of assets

Description

Seismic operations are complex logistical undertakings. As such a logistics risk map will help identify potential hazards, obstacles, unsuitable terrain, sand dunes, and patches of dense vegetation that will impact on the operational process of a seismic crew. These maps are delivered on the project/license scale.

A seismic survey design aims at providing an acquisition geometry that is optimal for the geophysical goal whilst ensuring safety, meeting quality requirements and being financially viable. It is likely that there is a compromise between the ideal situation and restrictions placed by the terrain. 

The selection process for locations suitable for use as base camps, fly camps, helipads and equipment drop zones needs to consider potential exposure to HSE (Health, Safety and Environment) risks and logistics planning by establishing the existing lay of the land and the current infrastructure in place.

HSE considerations will vary depending on the purpose of the location selected; however, the main points will include access, flood liability, any clearance required, sanitation and waste disposal, fuel storage and spill response mitigation and emergency response times to key locations around the project. Considerations for helipads and drop zones additional to the land clearance required include; elevation models, prevailing wind roses, tree height estimates and existing infrastructure like power lines (which all should be assessed when planning pad locations), fly away zones and long line corridors.

Logistics considerations include predicted travel time to various key locations throughout the project area to minimise both time exposure to risks travelling to and from any given operation area and to coordinate operations much more smoothly, with reduced travel times leading to more efficient and cost effective operations.

Understanding available access types and seasonal changes to their usability will help with decisions regarding the optimum time to conduct an operation, considering both risk exposure and potential time and cost savings.

A seismic logistics map is an integrated product in that the result is a cost map that uses a variety of products and aligns risk associated to each feature mapped. A seismic logistics risk map will help drive survey design, the scouting operation and daily operations on a seismic crew. The map should be flexible (meaning it has to be frequently updated) to adapt to changing conditions (access, weather, political etc.).

Known restrictions / limitations

  • Cloud cover would be a limitation on the optical data, most commonly in tropical areas, however archive imagery should provide mitigation against this.
  • Seasonality will have an impact so it is important for the user to understand when the image was acquired and the preceding weather conditions.
  • In dense vegetation where bare earth models are needed (for example in Seismic Planning) EO derived products cannot provide a solution.
  • Elevation mapping from DEM data is limited by the availability of DEM data (i.e. high latitudes coverage is poor). DEM data derived from stereo pairs can have a lead time of 3 weeks, but have a higher degree of accuracy than freely available lower resolution DEM’s. Radar derived DEM data are dependent on view direction and can be affected by shadows in mountainous regions.

Lifecycle stage and demand

Pre-licensing

Exploration

Development

Production

Decommissioning

 

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Exploration:

  • Seismic logistic operation map is only used in the exploration stage. Depending on the location the seismic logistic operation map will highlight; inaccessible areas, highlight best locations for campsites, mark where pipelines, farms, military areas are. The map provides an input into the modelling of expected daily/weekly/monthly production. Good information and planning will help minimise environmental impact and identifying key locations and risks in advance of operations.

Geographic coverage and demand

Global coverage (with a few restrictions see below). Demand in remote regions is high.

CHALLENGES ADDRESSED

OTM:012 Identifying conflicting sources of seismic signals

OTM:043 Anticipating areas of high seismic impedance

OTM:044 Identifying steep terrain for seismic vehicles

OTM:045 Identifying soft ground for seismic vehicles

OTM:046 Identifying variations in trafficability for seismic vehicle

OTM:053 Understanding the near-surface for explosive charge placement

OTM:058 Identifying ground conditions susceptible to poor coupling

 

HC:1211 Planning bridging through a tropical forest
HC:1303 Planning heliports, camps, and drop zones in forested areas

PRODUCT SPECIFICATIONS

Input data sources

Optical: VHR1, VHR2, HR1, HR2, MR1

Supporting data:

  • Digital elevation models (DEM)
  • Existing  GIS data such as infrastructure and assets
  • Local knowledge

Spatial resolution and coverage

Spatial resolution: 1 m – 90 m pixel size

Minimum Mapping Unit (MMU)

Variable, depending on source data resolution MMU as small as 0.5 ha is possible.

Accuracy / constraints

Thematic accuracy: 80-90%

Spatial accuracy: The goal would be one pixel, but depends on reference data

Accuracy assessment approach & quality control measures

Stratified random points sampling approach utilizing in-situ measurements and any available published data or reports. Statistical confusion matrix with user’s and producer’s accuracy as well as kappa statistics for hydrological network and catchment area mapping.

Frequency / timeliness

Observation frequency: Archive data can be used although new acquisition may be a requirement in some situations. The frequency is constrained by client needs, satellite revisit and acquisition, but also processing requirements. Depending on the requirements of the customer the best suitable satellite sensor has to be chosen regarding spatial / spectral resolution as well as revisit frequency.

Timeliness of delivery: Delivery in time with project planning requirements. Archive data can be used to good effect if the prevailing conditions are known and the time of year is accounted for.

Availability

Archive data

On-demand acquisition

Delivery / output format

 Download Product Sheet

 

 

Lead Author:WesternGeco
Peer Review:Hatfield Consultants

Author(s):

Andrew Cutts

Document Title:

Seismic logistics operation map & base camp mapping

# of Pages:

5

Circulation:

Internal – Project consortium and science partners

 

External – ESA

 

 

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