For calibrating bound vs free fluid in sub-1 mD Triassic fluvial reservoirs, has anyone gotten defensible T2 cutoffs from a field-portable CPMG on 1–1.5" plugs, same-day at a Midland core shop, that hold up against lab GeoSpec + MICP/SCAL integration? I’m trying to understand the typical bias and variance you’re seeing when those cutoffs feed Timur–Coates Sw in Techlog and ultimately net pay; any workflows or QC flags that move the needle?
Works, but on sub‑1 mD Triassic sands the “same-day at a Midland core shop” runs usually push the T2 cutoff 2–4 ms higher than GeoSpec, which bumps Timur–Coates Sw by about 5–8%. I’ve had best luck running two GeoSpec‑tied reference plugs per poro‑perm bin and forcing a simple cutoff shift in Techlog; insist on TE ≤0.2 ms and ≥8k echoes on those 1–1.5″ plugs. Did they log TE/gain/temp for your batch, or can you drop in a brine‑saturated check plug between runs?
Quick example: on sub‑mD Triassic plugs we fixed TE at about 200–250 µs, held the unit at 35°C, and ran a 3% NaCl brine‑sat check plug hourly; if its modal T2 was >1 ms off our GeoSpec baseline we shifted the field cutoff by the same amount, which pulled Timur–Coates Sw to within about 2–3%. @elizabeth82 did the shop log TE/gain/temp so you can apply that correction?