Back to Basics: Tops Picking

Top Tips for Tip-Top Tops Picking

Are You on Top of Picking Your Tops?

In oil and gas geology, “picking tops” is the process of identifying and marking key stratigraphic boundaries or formation tops within well logs. This task is crucial for understanding the subsurface structure, as these tops define reservoir boundaries, help with correlation between wells, and guide drilling decisions. However, picking tops comes with significant challenges, particularly around naming conventions and human error, which can impact data accuracy and consistency.

Key Challenges in Tops Picking

Inconsistent Naming Conventions

Across different fields, companies, or even geologists, naming conventions can vary widely. One geologist may label a particular formation as “Top Sandstone,” while another calls it “Sand A.” This inconsistency makes it difficult to correlate tops across projects and creates confusion in data interpretation. Standardizing naming conventions is essential but can be challenging to enforce manually.

Subjectivity and Human Error

Tops picking is highly interpretive. Different geologists may interpret formation boundaries differently based on their experience and subjective judgment. This subjectivity can introduce errors when multiple geologists work on the same project, especially in areas where the data isn’t straightforward or where formations are thin or complex. Even skilled geologists can miss subtle details or make inconsistent picks across large datasets.

Time-Consuming Process

Manual tops picking is repetitive and time-intensive, especially for large projects with hundreds of wells. Geologists spend considerable time analyzing logs and making interpretations that, if done inconsistently, could cause delays or errors during interpretation and development.

Predictive Assistance in Tops Picking

With advances in machine learning and artificial intelligence, software can now assist geologists with predictive tops picking, offering several key benefits.

Improved Consistency

Predictive algorithms can learn from existing data and apply the same interpretation across multiple wells, ensuring that formation tops are picked consistently. This reduces human error and ensures that tops are named and correlated reliably across the dataset.

Faster Interpretation

Predictive tops picking allows geologists to quickly generate preliminary tops, which they can then review and refine. This significantly reduces the time spent on initial interpretation, allowing geologists to focus on more complex or uncertain areas rather than manually marking every well.

Enhanced Collaboration

With predictive models suggesting standardized tops names and picks, it’s easier to collaborate across teams and regions. Consistent naming and correlation make it simpler to share and interpret data, avoiding misunderstandings and misalignments in the interpretation process.

Top Tips for Efficient Tops Picking in SeisWare

Standardize Naming Conventions

A few options exist within SeisWare to either rename tops or work with existing naming conventions.

• Use the “Merge Tops” function to merge tops existing under different formation names and sources under one standard name
• Use the “Formation Aliasing” function to create lists of formations aliases (alternate names). These can then be read and displayed in the Log editor and Cross Section Viewer without having to overwrite them. Import/export alias lists to keep naming conventions consistent between users.

Run Tops calculations

• Use the Tops Calculator to quickly create isopach maps or perform any bulk tops calculations

Set Displayed Tops

• Use this function to create lists of tops that you want to display on the Basemap or in the Seismic Viewer. You can color the tops by formation or source to differentiate between them.

Make it Colorful

Sometimes a pop of color helps to interpret and communicate information. SeisWare users can approach this well-by-well or map a larger area.

• For discrete points, visualize and display top depth values that correspond to a given color bar on the Basemap.
• Create a map of the values right from the Basemap using Quick Grid and Contour function. Outline an area with your mouse for an instant visual.

Switch on predictive tops picking

• Use the Predictive Tops function to quickly pick tops across a region or pick multiple tops in a cross-section without having to change the top name with every click.

A Collaborative Approach to Interpretation

Predictive tops picking isn’t about replacing the geologist but rather augmenting their expertise. By combining a geologist’s deep understanding of the geology with the consistency and speed of computer algorithms, predictive tops picking enables more efficient, reliable, and standardized interpretation.

In short, predictive tops picking addresses many of the traditional challenges—namely, inconsistent naming, subjectivity, and time demands—while allowing geologists to focus on the intricate, nuanced aspects of interpretation that require human insight. With predictive assistance, geologists can work more efficiently and produce more accurate subsurface models, ultimately leading to better decision-making in exploration and production.

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