How STRYDE processing and STRYDE surveys fit together to deliver a faster, better seismic image

by STRYDE
May 30, 2023 11:21:40 AM

When it comes to processing seismic data acquired on land, there are several common challenges that companies typically face which can impact the quality and time to deliver the seismic data required for geologists to begin the interpretation process in a timely manner.  

Addressing these challenges requires specialised skills, expertise, and technology to ensure that accurate subsurface models are created.

In this article, Amine Ourabah, Chief Geophysicist at STRYDE discusses the most common challenges he has experienced first-hand when processing seismic data acquired on land, and how STRYDE’s tried and tested solution, which he has helped to create, has been uniquely designed to overcome these issues to deliver a faster, better seismic image. 

Amine with node and Vibe

The challenges: 

“Processing seismic data, in general, is a complex task with various challenges, ranging from noisy data, complex geologies, limitations in the seismic acquisition, to handling a big data volume, sorting a multidimensional dataset, and applying adequate algorithms at each stage of the process. However, land seismic data processing is particularly more challenging for several reasons, the three most important ones in my view are: 

1. Noise

Land data is typically much noisier than marine data due to cultural noise and the complexity of the wave propagation within the near-surface which is very rarely a homogenous medium. The (often) irregular spatial sampling of land data makes this problem even more difficult to address.  

This presence of noise affects all seismic products, often making the processing sequence more complex, longer to complete, and more prone to damaging useful signal. 

Impact:

If the noise is not removed properly, it will ultimately impact the quality of the final product and its reliability for an accurate interpretation. It also increases the turnaround time and the cost of the processing.

2. The near-surface

The near-surface is a complex medium that not only generates loud surface wave noise but also acts like a distorted lens and deforms the deeper image - which is usually the target. It, therefore, requires to be modelled accurately enough to be able to correct for those distortions and image the target zone accurately. 

Impact:

It is not uncommon in land processing to spend more than 1/3 of the project time in solving the near-surface challenges. Although tools to model the near-surface exist, the process is still time-consuming and, at times, very manual-intensive when the data is too complex to be processed automatically. This has an impact on the turnaround and the quality of the final products.

3. Elastic propagation effect 

Unlike marine surveys, land surveys have, in general, both sources and receivers placed in the ground; an elastic medium that has the effect of capturing aspects of the wave propagation that involve P waves and S waves interactions. Processing land data using P waves only can therefore be challenging because of these converted waves.

Impact:

This complex wave propagation makes modelling wave propagation in land data very difficult and is the main reason why the latest advances in seismic imaging methods that produce spectacular result in marine environments (exp: FWI) often fail to work on land data. This forces a series of assumptions to be taken as well as a very interpretative approach to processing which is time-consuming and prone to errors. Ideally, one would like to acquire and process the data in its 3- components form when possible, however, this comes with its own challenges too.”

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The solution 

“In the last couple of decades, it has been proven that high trace density seismic delivers better quality seismic products, and the main reason for this is that high trace density samples noise better, simplifies the processing sequence, and makes most existing tools work better. This ultimately delivers faster and better results to the client. 

“The nodal technology developed by STRYDE is a key enabler to this, allowing companies to acquire high-trace density seismic data at a reasonable cost, thanks to the sensor's small size and affordability. 

Why our solution is different: 

“At STRYDE, we leverage our team’s expertise, technology, and the power of high trace density to simplify the processing sequence and reduce complex parametrisation steps, leaving only the most impactful ones. 

“The STRYDE processing team has access to one of the most powerful Centres of High-Performance Computing (CHPC) in the world, with 22 Pflop of CPU power and several petabytes of disk space. Combined with processing software designed to handle high-density seismic data, we can process any size 2D or 3D project in a record time using our CHPC environment to produce several parallel processing routes with migrated images as a QAQC tool instead of a final product. This allows us to identify very quickly the best processing flow, and confidently bypass steps that have negligible effects on the final product. 

“When high-density data is used, usually this approach converges to a near-final quality product at an early stage in the processing sequence, which means our clients can have access to exceptionally good intermediate products (migrated images) while the processing team is still progressing toward the best possible final product.”

Processing team

The proof is in the pudding…

“In general, when the STRYDE Nodes™ are used for high-density seismic acquisition, we usually see a 30-50% reduction in data processing turnaround time, with an increased quality when compared to conventional approaches. When the STRYDE acquisition system is used, we can access our system whilst it’s still in the field and get a head start on processing as soon as the first dataset is harvested, allowing us to deliver an even faster turnaround”.

Some examples of our ability to reduce turnaround time include: 

Survey description 

STRYDE data processing time

Estimated data processing time using conventional methods 

Full production processing of 1000km of high-density 2D lines 

3 months

6 months to 1 year

Field-style processing of 140km2 of 3D data in the Middle East

1 week

4-6 weeks

Full production processing of 1km2 of an ultra-high-density 3D survey (287 million trc/km2) through 3 sequences (2 different types of sources)

12 weeks

6-9 months

Conclusion

“Companies must capitalise on the benefits of high-trace density seismic acquisition and its ability to fast-track processing to obtain high-quality seismic images promptly. Given the significant improvement in acquisition time and cost, acquisition and processing have become now, more than ever, close, and compact processes allowing exploration teams to achieve their ultimate goal much more efficiently than ever before. 

The availability of inexpensive seismic receiver technology has made high-trace density an affordable option for any industry, enabling companies to obtain critical information in the early stages of exploration and make informed decisions accordingly. 

If I could offer advice to companies looking to acquire seismic on land at pace, and without compromising image quality, I would say…

✔️ For survey design: go as dense as possible and trade arrays with single-point sources and single-point receivers.

✔️ For source operations: don’t be afraid to blend sources if it allows you to increase your production and source density, the benefit of the added trace density far outweighs the deblending effort.

✔️For receivers: go nodal and single sensor to benefit from low cost and flexibility. 

✔️ For processing: go dense and simplify the sequence to let the processing be data-driven instead of relying on iterative complex flows with bespoke parameters”.

Discover more about seismic data processing with STRYDE

About STRYDE Processing: 

Our team consists of experienced land processing experts who joined us from companies like CGG, WesternGeco, Shearwater and BP with 22 years average experience across team members.  

We can assist clients across the full acquisition process, from survey design to designing the most optimum processing sequence to achieve their goals. 

All members of the team are trained in using the STRYDE system and can work closely with your acquisition team to make the data transfer to the processing environment as swift as possible using fast access to the STRYDE system (if used). 

STRYDE processing team has a deep understanding of the STRYDE data format and can take advantage of the available information in the raw data to QC and fast-track your deliverables. We are also familiar with common pitfalls in nodal single-sensor seismic processing which can avoid a lot of unwanted re-runs.

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