Well Test Analysis

Pressure transient testing from first principles: the diffusivity equation, drawdown and buildup analysis, the Bourdet derivative and diagnostic plots, wellbore storage and type curves, faults and reservoir limits, dual-porosity and layered reservoirs, fractured horizontal wells and rate-transient analysis, gas deliverability, falloff and step-rate tests on disposal wells, and test design with interference testing and deconvolution, applied to Cardium wells in Alberta, a Nisku disposal well and the testing requirements of AER Directive 040.

PET-360 Year 3 3 credits 12 lessons · 3 h 46 min ▶ Video lessons coming soon

Offered by HSM University · Petroleum Engineering

This is the Canadian version of this course. See the American version.

What you'll learn

  • Explain what a well test measures, describe the main test types and equipment, and state test objectives in terms of the decisions they support.
  • Derive the radial diffusivity equation, use dimensionless variables and the line-source solution, and apply superposition in space and time.
  • Analyse a drawdown on a semilog plot to find permeability-thickness and skin, and convert skin into an additional pressure drop and flow efficiency.
  • Analyse buildups with Horner and MDH plots, estimate p*, choose the effective producing time and correct p* to the average drainage-area pressure.
  • Compute and read the Bourdet pressure derivative on log-log diagnostic plots, identify flow regimes from their signatures and recognize non-uniqueness.
  • Quantify wellbore storage, use storage-and-skin type curves to estimate kh, C and skin, and separate partial-penetration skin from damage.
  • Identify sealing faults, channels, constant-pressure and closed boundaries, estimate distances with image wells and the radius of investigation, and design a reservoir limit test.
  • Interpret dual-porosity responses with the Warren and Root model, estimate ω and λ, and distinguish layered and radial composite reservoirs.
  • Analyse fractured vertical and multistage horizontal wells through bilinear and linear flow, and apply rate-transient analysis to production data.
  • Use pseudo-pressure and rate-dependent skin in gas well tests, and analyse flow-after-flow and isochronal deliverability tests with the back-pressure and LIT methods.
  • Analyse injectivity and falloff tests, interpret step-rate tests for formation parting pressure, and explain why injection pressures are regulated.
  • Design a well test from its objective, plan interference and pulse tests, explain deconvolution, and write an integrated interpretation report with uncertainty ranges.

Course content

12 lessons · 3 h 46 min total · final exam

  1. 1 Why test wells: objectives and test types 22 min · quiz
  2. 2 The diffusivity equation and dimensionless variables 21 min · quiz
  3. 3 Drawdown test analysis 20 min · quiz
  4. 4 Buildup test analysis 19 min · quiz
  5. 5 The pressure derivative and diagnostic plots 16 min · quiz
  6. 6 Wellbore storage, skin and type curves 17 min · quiz
  7. 7 Boundaries and reservoir limits 19 min · quiz
  8. 8 Naturally fractured and layered reservoirs 16 min · quiz
  9. 9 Hydraulically fractured wells and rate-transient analysis 19 min · quiz
  10. 10 Gas well testing and deliverability 20 min · quiz
  11. 11 Injection, falloff and step-rate tests 19 min · quiz
  12. 12 Test design, interference testing and the capstone interpretation 18 min · quiz
  13. E Final exam 20 questions

Requirements

Recommended background. You can start any course at any time.

Description

Pressure transient testing from first principles: the diffusivity equation, drawdown and buildup analysis, the Bourdet derivative and diagnostic plots, wellbore storage and type curves, faults and reservoir limits, dual-porosity and layered reservoirs, fractured horizontal wells and rate-transient analysis, gas deliverability, falloff and step-rate tests on disposal wells, and test design with interference testing and deconvolution, applied to Cardium wells in Alberta, a Nisku disposal well and the testing requirements of AER Directive 040.

Part of the Engineering stream, typically taken in year 3.