Well Testing 
Design | Interpretation | Analysis - We Can Help

Well testing is essential for reservoir characterization and permitting. We can help you with all your needs of injection well testing; test design, testing and interpretationWhether it is Step-Rate testing for establishing fracture gradient & well Injectivity or Pressure Fall-Off (PFO) test to determine permeability, skin & pressures to determine storage capacity. We can provide lifecycle support for testing & analysis needs. 

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WHY WELL TESTING IS IMPORTANT IN CO2 INJECTION?

Well-testing is a mandatory requirement of EPA and GHG Protocol for CO2 well permitting and injection for geologic storage in saline aquifer. The test is usually done in the ‘site characterization’ phase as part data acquisition for detailed site characterization, after the ‘site screening,’ and ‘site evaluation’ phases are completed. 

WHAT ARE THE OVERARCHING OBJECTIVES?

 A stratigraphic well is drilled for data acquisition and well testing has three main objectives to confirm:

  1. STORAGE CAPACITY 

  2. RESEVOIR INJECTIVITY

  3. WELL & SEAL INTEGRITY

WHAT DATA IS ACQUIRED & ANALYSIS DONE?

A stratigraphic well is drilled to acquire detailed data for reservoir characterization and testing. Sometimes an observation well may also be drilled to observe the response of CO2 injection. The acquired data includes:

  1. CORE DATA & ANALYSIS

  • Conventional Core data (Porosity & permeability, Kv & Kh) 

  • Special Core Analysis (SCAL) – Displacement efficiency (ED) CO2 displacing brine

  2. OPENHOLE LOGS/SAMPLES

  • Identify injection Zone 

  • Injection zone Depth (TVD)

  • Formation salinity (mg/l)

  • Injection zone (reservoir) temperature (0F) & pressure (psi)

  • Reservoir CO2 storage capacity (along with core data)

  3. WELL-TEST

  1. STEP-RATE TEST (Shorter test in injection well)

  • Regional Fracture gradient (psi/ft)

  • Estimated fracture pressure (psi)

  • Stabilized CO2 Injectivity (Tonne/day)

  • Stabilized Injection pressure

  • Well-Integrity

2. INJECTION / PFO (Extended test in injection well /observation well)​​

  • Reservoir permeability (md), injectivity Index & skin

  • Well Integrity

 4. SURFACE & RESERVOIR MONITORING

  1. Metering CO2 injection pressures and rates at the wellhead

  2. Measuring downhole reservoir pressures and temperatures at:

    • CO2 Injection well

    • Observation well

  3. Micro-seismic Monitoring

  4. Cross-Well Seismic survey

  5. Surface gas Sensors

  6. Soil gas sensors (Perfluorocarbons tracers added to injection stream)