Intermediate Petrophysics · Module I1
Depth Matching and Splice Integrity
Depth is a calculated value, not a measurement, and every property computed from logs inherits its errors. The module covers depth reference systems, the common causes of mismatch, manual and cross-correlation depth matching, building a splice from several runs, flagging bad hole, and the QC package a reviewer expects before interpretation starts.
- Level
- Intermediate
- Position
- Module 1 of 8
- Video
- About 15 minutes, narrated
- Format
- Narrated video lesson and slide reading view; with the certified option, a quiz whose pass unlocks the next module.
What the module covers
- MD, TVD and TVDSS references
- Causes of depth mismatch between runs and tools
- Tie-point and cross-correlation depth matching
- Deciding which run goes where in a splice
- Repeat sections and environmental corrections
- A base-data QC checklist for peer review
Learning outcomes
After the module you should be able to:
- Produce defensible base data for peer review and reruns.
- Match depths between logging runs, and between logs and core, and record the shifts
- Build a log splice and justify it
- Prepare a QC package that answers a reviewer's questions about the base data
A short preview
A depth shift of a foot or so between the gamma ray and the resistivity is easy to miss on a screen and large enough to matter. In a thin, laminated reservoir it can set the resistivity of a shale against the porosity of a sand, and the saturation computed from that pair is wrong in a way no parameter choice will fix. That is why depth matching comes first in the intermediate track, and why the shifts applied are recorded as part of the interpretation rather than buried in the loading step.
Who it is for
Petrophysicists and geoscientists with some interpretation experience, and engineers who review petrophysical inputs before they reach a volumetric or simulation model.
Prerequisites: The Basic Petrophysics track, or equivalent working experience.
Take the module in the Learning Hub
Intermediate Petrophysics: Eight applied modules with checkpoints; with the certified option, pass each quiz to unlock the next lesson. The lesson opens in the Learning Hub once the track is purchased; graded quizzes and the certificate come with the certified option.