Well-log data extraction
Well-log data extraction
Curve values from the CSVs are converted back to pixels using each track's scale, the depth anchors read from the printed labels, and the per-row sideways shift measured on the scan. Nothing is copied from the tracing step, so this shows the final data, including blanked samples.
SP is relative, so its line sits on the SP ink, not on a scale. Hatched bands mark intervals the logging engineer annotated "pulled tight" (tool stuck, then jumped free), widened to cover the flat stretches; values there are flagged in the CSV's QUALITY column and are not formation data. Run 3's solid track-2 curve is the laterolog-8; its dashed deep induction duplicates the conductivity and is not traced separately. In run 3 the CSV values below 12,222 ft are spliced across the logged SP shift (+43.3 mV); the line is drawn where it was recorded. Conductivity is on a 500 to 0 mmho/m scale in track 3. Where a curve ran off scale it is read from its backup trace: run 1 conductivity above 500 mmho/m on the 1000–500 backup, and run 2's track-2 induction at 11,005–11,505 ft on the 0–200 backup; the line breaks where the scale changes. The run 1 short normal (16-inch) is traced on 0–20 ohm-m. Neutron and SP in run 3 (DIL) are traced from 11,645 ft; above that the curves tangle with the run-change arrow below the casing shoe. Track 2 in run 1 also carries an amplified short normal (0–4 ohm-m): the same short-normal measurement at 5× sensitivity, not a separate channel, so it is not extracted.
Drill rate is drawn solid where traced and dotted where short gaps were interpolated. Markers in the right-hand margin are the annotations read by eye (gas shows, mud checks, bits, surveys, carbide lag). Each rule across the log shows the depth assigned to its note.
The scans these values were extracted from, as obtained from CalGEM well records for API 0411120436.