28th Aug, 2024

Old energy vs new energy: key differences in seismic acquisition from Gehrig Inc.

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Knowledge is power and subsurface knowledge plays a crucial role in reducing risk and enabling informed decision-making. For decades, the oil and gas industry has leveraged the power of seismic data to gain valuable insights into the subsurface for optimal well placement and enhanced recovery. Still, other sectors have struggled to access this critical information due to the traditionally high costs and labor-intensive processes of acquiring and visualizing high-definition seismic data.

However, advancements in technology, AI, and computing power over the past five years have dramatically reduced the cost and time required to create high-resolution seismic images. This evolution has made seismic data an affordable and accessible tool for a wide range of industries, including wind farm development, hydrogen production, groundwater identification, and even dam construction for hydropower producers.

Gehrig Inc., a trusted geophysical data provider in Texas, is one of the companies at the forefront of applying advancements in geophysical methods for their clients’ benefit. This has enabled them to expand their portfolio beyond the oil and gas sector, acquiring seismic data for new and emerging industries using cutting-edge technology and techniques.

We had the opportunity to sit down with Michael Gehrig, a licensed engineer, geophysicist, and owner of Gehrig Inc. During our conversation, we explored the key differences between acquiring seismic data for oil and gas versus new energy projects and learned how he is leveraging STRYDE’s seismic technology to obtain high-definition seismic data for his clients.

Traditional oil and gas exploration vs. new energy projects

"Over the past few years, we've observed a significant increase in demand from new energy sectors in Texas, a clear indicator of the region's commitment to advancing renewable energy and sustainable development. This growth is being fuelled by a combination of state and federal incentives designed to attract investment in wind, solar, and other clean energy projects. Given the smaller footprints and more constrained exploration budgets typical of these projects, we need to deliver high-definition seismic data at an affordable price. The adoption of STRYDE’s technology is instrumental in enabling us to meet these demands effectively and efficiently."

Key differences

“In my experience, the top three main differences in seismic surveys for old energy vs new energy surveys that we at Gehrig have worked on are:

1. Objective and depth of investigation

Oil and gas exploration:

  • Objective: To identify and map hydrocarbon reservoirs deep within the Earth
  • Depth: Seismic surveys in North Texas are focused on shallow to moderately deep subsurface structures, ranging from 1,000 to 10,000 feet, to effectively identify sedimentary layers and geology where oil and gas might accumulate.
Figure 1: Seismic reflection for oil and gas
Figure 1: Seismic reflection for oil and gas

Dam construction and rehabilitation:

  • Objective: To assess near-surface geology for stability and safety, ensuring a solid foundation for the dam and to monitor the structural health, signs of stress, and weak zones.

  • Depth: Surveys typically focus on the upper few hundred feet of the subsurface to evaluate the foundation materials required and identify any potential hazards like faults or preferential seepage zones.

Wind farm development:

  • Objective: To determine soil and rock dynamic properties used for turbine foundation stability/cyclical load design and to assess potential geohazards that could impact the long-term operation of the wind farm.

  • Depth: The focus is primarily on the upper 100 to 300 feet of the subsurface, where the turbine foundations will be anchored. This is critical for ensuring that the soil and rock beneath the turbines can support the dynamic loads caused by wind forces.

2. Survey techniques and resolution

Oil and gas exploration:

  • Techniques: Uses high-resolution 2D and 3D seismic surveys with large sensor arrays spread over vast areas to map deep subsurface features. Sensor spacing is typically between 55 to 220 feet apart.

  • Resolution: While resolution is important, the primary goal is to capture large-scale features at depth rather than fine details near the surface.

Dam construction and rehabilitation:

  • Techniques: Utilizes seismic refraction, Multi-channel Analysis of Surface Waves (MASW), and reflection seismic to gather detailed data about near-surface layers. Other techniques are deployed depending on the objective, namely electrical resistivity tomography, ground penetrating radar, and self-potential. Sensor spacing is much tighter (5 to 10 feet) to capture small-scale features and ensure foundation stability.

  • Resolution: Ultra-high-resolution data is needed to identify fine-scale subsurface features, such as fractures, faults, and variations in soil and rock types and properties.

Wind farm development:

  • Techniques: Similar to dam construction, techniques such as MASW, seismic refraction, transient electromagnetic (tTEM), and electrical resistivity are used to assess the near-surface conditions. The surveys are often conducted with tight sensor spacing to ensure detailed imaging of the subsurface.

  • Resolution: High resolution is critical for identifying variations in soil properties, potential karsts, and other geohazards that could affect turbine stability and longevity

    Figure 2: MASW for wind farms
    Figure 2: MASW for wind farms

3. Seismic hazards and risk assessment

Oil and gas exploration:

  • Hazards: The focus is on gathering information that allows navigating around hazardous subsurface conditions during drilling operations, namely karstic areas.

  • Risk Assessment: Mainly involves economic risks related to the viability of hydrocarbon reservoirs.

Dam construction and rehabilitation:

  • Hazards: Identification of geohazards like faults and preferential seepage zones is crucial for designing dams that can withstand earthquakes and other dynamic forces.

  • Risk Assessment: Involves evaluating the potential for dam failure due to seismic events, which could lead to catastrophic consequences.

Wind farm development:

  • Hazards: Seismic data helps assess the risk of ground instability, including identifying any faults or other subsurface anomalies that could affect turbine foundations.

  • Risk Assessment: Ensures that the wind farm’s turbines are sited on stable ground to minimize the risk of structural failure or reduced operational efficiency due to ground movement."

The role of STRYDE in overcoming challenges in new energy markets

“The historically high cost of seismic acquisition has led to its limited use in the new energy sector, resulting in it often being overlooked as a tool for exploration or geohazard identification. Consequently, many potential clients in the new energy sector have had little exposure to geophysics and may be unaware of the significant value seismic data and other geophysical tools can bring to their projects.This is where STRYDE's technology is a game-changer for us. By providing seismic equipment that is more affordable, lightweight, and faster to deploy and download data, STRYDE has empowered companies like ours to deliver high-quality seismic services efficiently and cost-effectively, to any industry. The ability to deploy higher channel counts at a lower cost per channel enables contractors to offer detailed, high-resolution surveys without exceeding budgetary constraints, making seismic data acquisition more accessible to the new energy sector.”

Conclusion

For energy developers looking to make data-driven decisions, reduce risks, and optimize design processes, investing in seismic surveys with the support of STRYDE's technology offers substantial added value in aiding critical decisions like foundation design for wind turbines and identifying potential geohazards in construction projects that could impact project viability.

If you would like to learn more about Gehrig Inc, click here.

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