SEE Protocol · Stanford/SRI Method · Live Demo

Pore Pressure Elicitation Simulator

Step through a real expert elicitation interview for a Gulf of Mexico sub-salt well. Experience the SEE protocol firsthand — bias calibration, structured uncertainty quantification, and probabilistic decision output.

GoM Mississippi Canyon Sub-Salt Wilcox P10 / P50 / P90
1
Well Context
2
Bias Check
3
Elicitation
4
Dashboard
Facilitator Brief — Pre-Interview

Well Context: MC-596 Sub-Salt Wilcox

📋
Scenario: You are the elicitation facilitator. Before interviewing the pore pressure expert, you review the available well data and offset context. This information will inform — but not anchor — the expert's estimates.

Well Parameters

Well DesignationMC-596 #1 (Proposed)
BlockMississippi Canyon 596
Water Depth6,847 ft
Planned TD18,000 ft TVD
Target FormationWilcox Sub-Salt
Reservoir TypeTurbidite Sandstone
Structural PositionUp-dip, salt weld flank
Frac Gradient @ TD18.4 ppg EMW

Geological Column

Sea Water0 – 6,847 ft
Tertiary Sediments6,847 – 9,400 ft
Allochthonous Salt9,400 – 15,100 ft
Sub-Salt Sediments15,100 – 17,800 ft
⚑ Wilcox Target17,800 – 18,000+ ft

Offset Well Summary

Nearest OffsetMC-727 #1 (8.2 mi)
MC-727 PP @ 18k ft15.8 ppg (measured)
MC-504 PP @ 17.5k ft16.1 ppg (measured)
Avg Pre-Drill Error+1.6 ppg sub-salt
Salt Geometry DiffHigh — 3D seismic indicates structural complexity near salt weld
Pore Pressure MethodEaton's Sonic — pre-drill

Elicitation Protocol

MethodStanford/SRI SEE Protocol
Phase 1Asset identification ✓
Phase 2Bias training (next step)
Phase 3Structured interview ✓ (step 3)
Phase 4Documentation + encoding
Expert Being InterviewedSenior Pore Pressure Specialist
28 yrs GoM sub-salt experience
💡
Key concern: The 3D seismic shows a significantly different salt geometry vs. MC-727. The salt weld on the proposed well flank creates a sub-salt pressure shadow zone not captured by offset data. This structural complexity is exactly why expert elicitation — not just analog comparison — is required.
Phase 2 — SEE Protocol

Bias Calibration Exercise

Before any elicitation interview, the SEE protocol requires bias training. Provide your 90% confidence interval for each question — a range you are 90% sure contains the correct answer.

⚠️
Instructions: Enter a LOW and HIGH value for each question such that you are 90% confident the true answer falls between them. If you were perfectly calibrated, you would capture the answer ~9 out of 10 times.
Question 1 of 3
Question 1 / 3
What is the true vertical depth (ft TVD) of the deepest sub-salt well ever drilled in the Gulf of Mexico?
💡 Provide your 90% confidence interval — a range that contains the answer with 90% probability.
—
ft TVD
Question 2 / 3
What percentage of Gulf of Mexico deepwater wells encounter pore pressures more than 0.5 ppg above their pre-drill prognosis?
💡 Based on industry drilling data across GOM deepwater 2005–2023.
—
%
Question 3 / 3
When a sub-salt pore pressure ramp occurs in the GoM Wilcox, what is the average mud weight increase required compared to the pre-drill plan?
💡 Expressed in pounds per gallon (ppg) equivalent mud weight.
—
ppg
—
/ 3 correct
Calibration Accuracy
Expected (90%)
90%
Your Capture
—%
🎯
This bias pattern is exactly why Phase 2 debiasing exists in the SEE protocol. Experts with demonstrated overconfidence produce systematically narrower uncertainty ranges — underestimating tail risk in pore pressure predictions. The facilitator applies anchoring and adjustment corrections before proceeding.
Phase 3 — SEE Protocol · Stanford/SRI Questioning Path

Structured Elicitation Interview

The facilitator asks each question using the overanchoring-resistant questioning sequence. Your answers update the probability distribution in real time.

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Facilitator — Question 1 of 4
"Based on your experience with sub-salt formations in Mississippi Canyon — considering salt geometry variability, formation connectivity, and analog uncertainty — what is the LOWEST pore pressure gradient you would credibly expect at 18,000 ft TVD?

This is your P10: a value so low that only 1 in 10 geological scenarios would produce a pressure at or below this level."

SEE Protocol: Ask for extremes first to minimize anchoring on the most-likely case.

14.516.5 ppg
15.4
ppg EMW
🎙
Facilitator — Question 2 of 4
"Now, without anchoring on the value you just provided — what is the HIGHEST pore pressure gradient you consider geologically credible at 18,000 ft TVD?

This is your P90: the value you believe has only a 1 in 10 chance of being exceeded. Think about the worst plausible sub-salt pressure scenario: fault connectivity, deep aquifer communication, or severely overpressured Wilcox compartments."

SEE Protocol: High case before most-likely prevents compression of the upper tail.

15.518.0 ppg
17.1
ppg EMW
🎙
Facilitator — Question 3 of 4
"With your low and high cases established — what is your MOST LIKELY estimate?

This is your P50: the median. Equal probability of the true pore pressure being above or below this value. This is the single number most representative of your expectation, acknowledging the uncertainty range you've already defined."

SEE Protocol: Eliciting P50 last prevents it from anchoring the tails.

15.017.5 ppg
16.2
ppg EMW
🎙
Facilitator — Question 4 of 4
"One additional diagnostic: based on your experience with sub-salt pressure transitions in this region — at what depth (ft TVD) do you expect the pore pressure to begin ramping above the offset-well trend?

This depth defines where sub-salt pressure compartmentalization disconnects from the pre-salt pressure regime. It directly determines your casing point depth."

SEE Protocol: Spatial diagnostic — identifies the pressure transition zone for well architecture decisions.

15,50017,500 ft
16,400
ft TVD
Live Probability Distribution
Pore Pressure Gradient — 18,000 ft TVD
15.4
P10 ppg
16.2
P50 ppg
17.1
P90 ppg
Dashed line = offset data only (15.8 ppg)
AI Reasoning Capture
Expert inputs will appear here as you answer each question…
Elicitation Complete · SEE Protocol Output

Expert Elicitation Dashboard

MC-596 · Wilcox Sub-Salt
✅
Elicitation complete. The expert's probabilistic pore pressure estimate has been captured, encoded, and validated against offset data. The output below drives the well architecture decision.
Pore Pressure Probability Distribution — 18,000 ft TVD
Mud Weight Window
ParameterValueBasis
P10 Pore Pressure—Expert elicitation
P50 Pore Pressure—Expert elicitation
P90 Pore Pressure—Expert elicitation
Fracture Gradient18.4 ppgLOT + regional model
Recommended MW—P90 + 0.3 ppg margin
MW Window Width—Frac − Recommended MW
Casing Architecture Recommendation
1
36" Conductor
Set at mudline (6,847 ft)
2
22" Surface Casing
Set at 9,200 ft TVD (above salt)
3
16" Intermediate — Top of Salt
Set at 9,400 ft TVD (salt entry)
4
13⅝" Base of Salt Liner
Set at 15,100 ft TVD (base of salt)
★
13⅜" Pressure Ramp Liner Expert Elicitation Adds This
Set at 16,400 ft TVD — ramp onset identified by expert. Without elicitation, this string would not have been planned.
6
9⅞" Production Liner
TD @ 18,000 ft TVD
Decision Comparison
Decision Factor ✓ With Expert Elicitation ✗ Offset Data Only
Pore Pressure Estimate P10: — / P50: — / P90: — (full distribution) 15.8 ppg (single deterministic value)
Pore Pressure Uncertainty Quantified — — ppg spread Unknown — no tail risk captured
Planned Mud Weight — ppg (risk-informed) 16.1 ppg (offset + 0.3 ppg margin)
Ramp Onset Identified Yes — 16,400 ft TVD No — not visible in offset data
Additional Casing String Yes — 13⅜" ramp liner (proactive) No — discovered reactively at 16,400 ft
Well Control Risk Managed — mud weight exceeds P90 High — MW below P50 at ramp zone
Projected Outcome Well drilled safely to TD Well control event at ~16,600 ft TVD
Cost Impact
Well Control Event Prevented
$0
in projected cost savings
Expert elicitation identified a — ppg sub-salt pore pressure ramp that offset analog data missed entirely. Planning the 13⅜" ramp liner in advance added $2.1M in upfront cost — preventing a projected $14.3M well control + NPT event at 16,400–16,600 ft TVD.

ROI of elicitation study: 5.8× on this single well.
What the SEE Protocol Captured
🧠
Expert Pattern Recognition
28 years of sub-salt GoM experience encoded into a probabilistic estimate no algorithm can replicate from seismic alone.
⚖️
Calibrated Uncertainty
Bias-corrected P10/P50/P90 distribution that truthfully represents geological uncertainty — not false precision.
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Spatial Diagnostic
Ramp onset depth — a structural insight derived from expert synthesis of seismic + analogs, not computable from available data alone.
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Documented Decision Chain
Every reasoning step captured, encoded, and audit-ready. When the expert retires, the knowledge stays.
Assessment Report
Download Your Pore Pressure Assessment
Get a branded PDF summary with your P10/P50/P90 values, mud weight window, casing recommendation, and decision comparison — ready to share with your team.
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