Pressure and Fluid Contacts · Module P5
Compartments, depletion and excess pressure
Not every sand in a well shares one pressure system. The module subtracts a reference gradient from each test to build an excess pressure plot, reads compartments from parallel but offset water lines, recognizes depletion caused by production elsewhere, and fits each connected system on its own so that one line is never forced through two.
- Level
- Intermediate
- Position
- Module 5 of 8
- Video
- About 20 minutes, narrated
- Format
- Narrated video lesson with captions and slide reading view; with the certified option, a quiz whose pass unlocks the next module.
What the module covers
- Excess pressure against a reference line
- Choosing the reference gradient
- Offset water lines as a compartment signature
- Depletion and a second logging run
- Fitting each pressure system separately
- Telling supercharging, depletion and compartments apart
Learning outcomes
After the module you should be able to:
- Say from the evidence whether two sands are connected.
- Read an excess pressure plot for supercharging, depletion and compartments
- Explain what one line through two compartments does to a free water level
A short preview
Subtract a water gradient from every test and a single connected aquifer collapses onto a vertical line, so anything that departs from it stands out. Suppose two sands each show a clean water line with the same 0.45 psi/ft slope, but the lower one sits 40 psi higher. Parallel, offset lines like these mean two pressure systems that were not communicating when the well was logged. One line through both would give a gradient with no physical meaning and a free water level that belongs to neither sand.
Who it is for
Petrophysicists, reservoir engineers and geoscientists who screen formation pressure tests, pick fluid contacts and carry them into volumes for exploration, appraisal and development decisions.
Prerequisites: None required; working familiarity with well logs and volumetrics helps. The hands-on steps use the Pressure Analysis panel in Formation Evaluation.
Take the module in the Learning Hub
Pressure and Fluid Contacts: Specialty course, sold separately: eight modules that turn a formation tester report into fluid contacts you can defend, from screened tests and gradients to capillary entry height and a contact range in the volume. The lesson opens in the Learning Hub once the track is purchased; graded quizzes and the certificate come with the certified option.