Special Core Analysis

Special Core Analysis

A Complete Range of Special Core Analysis Services

Wettability, relative permeability (water-oil, gas-oil, gas-water), capillary pressure (porous plate, ultra-centrifuge, mercury injection), rock-fluid compatibility, electrical resistivity measurements, acoustic velocities, dynamic rock mechanics as well as other specialized services.

Most of the laboratory procedures listed can be performed at elevated reservoir pressures and temperatures. Live reservoir fluids can also be recombined and used. Many other special tests and test sequences can be designed to identify particular reservoir and production problems. Numerous cleaning, drying and sample handling procedures are available. Test results are available in many personal computer formats.


We now provide industry-leading services in CT Scanning and Drop Shape Analysis in addition to our previous range of special core analysis services.


Computed Tomography (CT) is used to calculate insitu saturations at reservoir conditions and to visualize the fluid distribution within the core.
Other applications for CT scanning include:
- CT images of full core, drilled plugs, and rotary sidewall plugs
- Sample screening for EOR, SCAL, and Rock Mechanics testing
- Works in concert with Rock Mechanics testing to visualize possible anisotropy

Drop Shape Analysis

- Interfacial Tension
- Contact Angle
- Spontaneous Imbibition

Special Core Analysis

Over 120 images captured in the first five seconds

Use the measured contact angle and spontaneous imbibition to calculate
the Wettability Index for oil and water

We use DSA to optimize fluids for:

- Drilling (well bore stability problems)
- Completion
- Stimulation (surfactant optimization)
- Water Flooding (low salinity flooding)

Of course we continue to offer the following services:

Special Core Analysis
1) Porosity and Permeability at Net Overburden Pressure


Air Permeability

Porosity and Air Permeability


2) Pore Volume Compressibility
The pore volume reduction is measured as a function of the increasing net overburden pressure. Porosity and pore volume compressibility is calculated for each net overburden pressure. A minimum of ten pore volume measurements are performed. The results are reported in tabular and graphic formats; porosity vs. confining pressure and pore volume compressibility vs. confining pressure. Maximum confining pressure is 10,000 psig.


3) Klinkenberg Permeability Steady-State
Gas permeability versus reciprocal mean pressure is plotted and the theoretical liquid permeability is calculated. The test can be performed at confining pressure up to 10,000 psig and pore pressures up to 2,000 psi (higher pore pressure optional).


4) Specific Liquid Permeability @ Net Overburden Pressure

5) Effective Fluid Permeability and Immobile Fluid Saturation

6) Basic Water Flood Test
Residual oil saturation and end point relative permeabilities are measured.

7) Water Flood Susceptibility
Oil recoveries versus water cut and number of pore volumes injected are reported. The reservoir viscosity ratio is simulated.


8) Rock Fluid Compatibility
Core floods performed at ambient or reservoir conditions are used to simulate and evaluate potential rock-fluid or fluid-fluid incompatibilities. Drilling, completion, stimulation or injection fluids can be tested on plug or full diameter core samples. Special equipment for highly corrosive acids is available.

Permeability as a function of throughput

Clay sensitivity and fines movements are estimated by reversing the flow direction. Various rock-fluid combinations can be tested.

Return Permeability

The permeability in the production direction is established. The treating fluid is injected in reversed flow (injection direction). The flow is restored in the production direction and the resulting permeability is compared to the original to evaluate formation damage or stimulation.

Critical Velocity

The interstitial velocity causing fines movement within the pores of the reservoir rock is measured. The test can be used in conjunction with wettability data to scale laboratory flow experiments and to optimize production/injection rates. The tests are conducted at reservoir temperature and por e pressure.


Capillary Suction Time

Capillary Suction Time (CST) is measured and can be used to screen mud filtrates or completion fluids before rock fluid compatibility tests.


Acid Solubility

Acid solubility is measured and percentage insoluble residue determined.

9) Unsteady-State Relative Permeability

Water-oil relative permeability. Water saturation increasing.

Water-oil relative permeability. Water saturation decreasing (performed after II-9.1 or II-9.2).

Gas-oil relative permeability. Gas flood in the presence of irreducible water saturation.

Gas-water relative permeability. Gas saturation increasing.


10) Steady-State Relative Permeability

Drainage and imbibition water-oil tests are available for plugs and full diameter samples. The test can be performed at ambient or reservoir pressure. The cost is a function of the sample size, porosity and permeability, test conditions and fluids used.


11) Formation Resistivity Factor and Cementation Exponent (m)

12) Formation Resistivity Index and Saturation Exponent (n).
Measured at ambient or confining pressure. Resistivity of the rock is measured at five different saturations.

13) Wettability-Modified Amott Test
Consists of three successive floods and two imbibition tests. Wettability index to water and oil is reported.

14) High PressureMercury Injection Capillary Pressure and Pore Size Distribution
Multipoint measurements are performed over a 2 to 60,000 psia pressure range. A test consists of several hundred points. The test can be performed on 1" x 1" core plugs or drilling cuttings since the volume resolution of this fully automated equipment is 0.0001 cc.
The surface area of the test sample is also measured. The pore size distribution (cumulative and incremental) and the Leverett J(Sw) function are calculated and reported at no extra charge. If reservoir condition conversion is desired, the interfacial tension, contact angle, brine and oil densities at reservoir conditions are required.


15) Porous Plate Capillary Pressure at six (6) saturation point

The test can be performed in conjunction with the Resistivity index measurement at ambient or confining pressure.


16) Ultra Centrifuge Capillary pressure

17) Caprock Analysis

Threshold pressure determination and seal capacity calculation.
Liquid permeability to 10-6mD


18) Acoustic Velocity Measurements – Dynamic Rock Mechanical Properties

Compression (P) and shear waves (S1 and S2 perpendicular to each other) are measured under triaxial loading conditions up to 10,000 psi. Poisson's ratio, Young's modulus, bulk modulus and shear modulus are determined.


19) Static Rock Mechanical Properties


20) Velocity Anisotropy for in situ Stress Azimuth






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30th Anniversary: 1989-201925

2019 marks the 30th year in operation for Midland-based Special Core Analysis Laboratiories, Inc. (SCAL, Inc.). We are proud to celebrate this anniversary by celebrating the people that enable our success - you, our clients!

DOWNLOAD: White Papers


- SCAL, Inc: Services & Capabilities 2019

- Lower Shale Porosities Are Better WTGS 2017

- The Dual Drop Method Wettability Measurement and Treating Fluid Optimization WTGS 2015

- From Nano-Gas to Commercial Oil and Gas WTGS 2014

- Measuring Gas to Find Shale Oil Generation

- Compaction Model for Oil and Gas Generation in Shale WTGS 2011

- Shale Analysis Presentation AAPG 2010

- Quick-Desorption™ Automated Shale Gas Desorption and Tight Rock Analysis: Sorption Isotherms Performed on Rotary Sidewall Cores