Unlocking Bypassed Reserves How Advanced Special Core Analysis (SCAL) Redefines Recovery Factors

Close-up view of a core sample showing detailed rock texture and porosity

Oil and gas reservoirs often hold more than what traditional methods reveal. Many reserves remain locked away, bypassed by conventional recovery techniques. Unlocking these reserves can significantly boost production and extend the life of fields. The key lies in understanding the reservoir rock and fluid behavior at a detailed level. This is where Advanced Special Core Analysis (SCAL) steps in. It redefines recovery factors by providing deeper insights into the reservoir’s true potential.

In this post, I will explain how SCAL helps identify and recover bypassed reserves. I will also show how specific SCAL services can support this process. You will learn why SCAL is essential for improving recovery and making smarter decisions in reservoir management.

What Are Bypassed Reserves and Why Do They Matter?

Bypassed reserves are portions of hydrocarbons left behind in the reservoir after primary and secondary recovery methods. These reserves are often trapped in complex rock formations or in zones with challenging fluid flow. They represent untapped value that can improve a field’s economics if recovered.

Traditional core analysis and well logging provide a general picture of the reservoir. But they often miss subtle rock and fluid properties that control fluid movement. This leads to underestimating the volume of recoverable hydrocarbons.

Recovering bypassed reserves means:

• Increasing the recovery factor beyond initial estimates

• Extending the productive life of the reservoir

• Improving the return on investment for development projects

  
  

Unlocking these reserves requires detailed knowledge of rock wettability, capillary pressure, relative permeability, and fluid saturations. This is exactly what Advanced Special Core Analysis delivers.

How Advanced Special Core Analysis (SCAL) Works

SCAL goes beyond routine core analysis. It focuses on measuring rock and fluid properties under reservoir conditions. This includes:

• Wettability evaluation

• Capillary pressure curves

• Relative permeability measurements

• Electrical properties of rock and fluids

  
  

These tests simulate the reservoir environment to reveal how fluids behave inside the rock pores. SCAL helps identify zones where oil is trapped by capillary forces or where water blocks oil flow. It also shows how wettability affects fluid distribution and recovery.

By understanding these factors, engineers can design better recovery strategies. For example, they can select the right injection fluids, adjust pressure maintenance, or target specific zones for enhanced oil recovery (EOR).

Example of SCAL Service Supporting Recovery

One service that stands out is the CoreLab Special Core Analysis. It offers comprehensive SCAL testing that includes wettability, capillary pressure, and relative permeability under reservoir conditions. This service helps operators identify bypassed oil zones and optimise recovery plans.

You can learn more about this service at CoreLab Special Core Analysis.

Key SCAL Measurements That Unlock Bypassed Reserves

Wettability

Wettability controls which fluid sticks to the rock surface. It affects how oil and water distribute in the pores. If the rock is water-wet, water tends to coat the pores and oil flows more easily. If oil-wet, oil clings to the rock, making recovery harder.

SCAL measures wettability using techniques like Amott tests or USBM methods. Knowing wettability helps predict how injected water or chemicals will move through the reservoir.

Capillary Pressure

Capillary pressure defines the force holding fluids in the pores. It determines the height to which water or oil can rise in the rock. High capillary pressure can trap oil in small pores, making it bypassed by conventional methods.

SCAL generates capillary pressure curves to quantify these forces. This data guides decisions on injection pressures and fluid types to overcome capillary barriers.

Relative Permeability

Relative permeability shows how easily oil and water flow together in the rock. It changes with fluid saturation and wettability. SCAL measures relative permeability at different saturations to model fluid flow accurately.

This helps engineers forecast production and design enhanced recovery techniques that mobilise trapped oil.

Electrical Properties

Measuring electrical properties helps interpret well logs and estimate fluid saturations in the reservoir. SCAL tests electrical resistivity and conductivity under reservoir conditions to improve log calibration.

This leads to better reservoir characterisation and identification of bypassed zones.

Integrating SCAL Data into Reservoir Management

SCAL data is not just for lab reports. It must feed into reservoir simulation and decision-making. Combining SCAL results with well logs, seismic data, and production history creates a full picture of the reservoir.

This integration allows you to:

• Identify bypassed oil zones precisely

• Design targeted EOR methods like chemical flooding or gas injection

• Optimise well placement and completion strategies

• Predict recovery factors more accurately

  
  

For example, the Schlumberger Special Core Analysis service provides detailed SCAL data and integrates it with reservoir models. This helps operators make informed decisions to unlock reserves efficiently.

Learn more about this service at Schlumberger Special Core Analysis.

Real-World Impact of SCAL on Recovery Factors

Several case studies show how SCAL improved recovery factors by unlocking bypassed reserves:

• In a North Sea field, SCAL revealed oil-wet zones with trapped oil. Adjusting water injection strategy based on this data increased recovery by 8%.

• A Middle East reservoir had complex capillary barriers. SCAL data helped design a surfactant flood that mobilised trapped oil, boosting recovery by 12%.

• In a US shale play, SCAL measurements refined relative permeability curves. This improved hydraulic fracturing design and increased production rates.

  
  

These examples prove SCAL’s value in turning overlooked reserves into production.

High angle view of laboratory equipment used for core analysis testing

Choosing the Right SCAL Service for Your Needs

Not all SCAL services are equal. You want a provider that offers:

• Testing under true reservoir conditions (pressure, temperature)

• Comprehensive measurements including wettability, capillary pressure, and relative permeability

• Integration with reservoir modelling tools

• Experienced technical support

  
  

Both CoreLab and Schlumberger provide top-tier SCAL services. CoreLab focuses on detailed lab testing with quick turnaround. Schlumberger combines SCAL with advanced reservoir modelling and consulting.

Evaluate your project needs and select a service that fits your goals and timeline.

Final Thoughts on Unlocking Bypassed Reserves

Bypassed reserves hold real value. You can unlock them by understanding the rock and fluid behaviour deeply. Advanced Special Core Analysis gives you this insight. It redefines recovery factors by revealing hidden oil and guiding smarter recovery methods.

Use SCAL data to improve reservoir models, design better injection strategies, and extend field life. Services like CoreLab Special Core Analysis and Schlumberger Special Core Analysis offer the tools you need.

Don’t leave oil behind. Unlock it with SCAL and boost your recovery today.