{
  "version": 1,
  "topic": "WC05",
  "title": "Why shoe depth matters in a MAASP calculation",
  "createdAt": "2026-10-24",
  "case": {
    "title": "Translate a fixed shoe-density margin",
    "premise": "Assumed approved shoe EMW 16 ppg, current uniform mud 12 ppg. Each depth represents a hypothetical different shoe.",
    "formula": "MAASP = (16 − 12) × 0.052 × TVDshoe",
    "variables": "This is the shoe-based arithmetic allowance, not a complete operational pressure limit.",
    "steps": [
      {
        "label": "Define the baseline",
        "calculation": "Shoe TVD (ft) = 5000",
        "explanation": "Assumed approved shoe EMW 16 ppg, current uniform mud 12 ppg. Each depth represents a hypothetical different shoe."
      },
      {
        "label": "Select the relation",
        "calculation": "MAASP = (16 − 12) × 0.052 × TVDshoe",
        "explanation": "This is the shoe-based arithmetic allowance, not a complete operational pressure limit."
      },
      {
        "label": "Substitute the values",
        "calculation": "4 × 0.052 × 5,000 = 1,040 psi",
        "explanation": "Retain intermediate precision. The displayed values are rounded only after evaluation."
      },
      {
        "label": "Read the result",
        "calculation": "Calculated allowance (psi) = 1040",
        "explanation": "The same equivalent density margin represents a different surface pressure at a different shoe depth."
      }
    ],
    "result": "Calculated allowance (psi) = 1040",
    "interpretation": "The same equivalent density margin represents a different surface pressure at a different shoe depth.",
    "control": "Shoe TVD (ft)",
    "columns": [
      "Shoe TVD (ft)",
      "Calculated allowance (psi)"
    ],
    "rows": [
      [
        3000,
        624
      ],
      [
        4000,
        832
      ],
      [
        5000,
        1040
      ],
      [
        7000,
        1456
      ],
      [
        8000,
        1664
      ]
    ],
    "baseline": 2,
    "rowNotes": [
      "Shoe TVD (ft) = 3000. Calculated allowance (psi): 624.",
      "Shoe TVD (ft) = 4000. Calculated allowance (psi): 832.",
      "Shoe TVD (ft) = 5000. Calculated allowance (psi): 1040.",
      "Shoe TVD (ft) = 7000. Calculated allowance (psi): 1456.",
      "Shoe TVD (ft) = 8000. Calculated allowance (psi): 1664."
    ],
    "provenance": "Original synthetic teaching calculation. Equations and fixed controls are stated here; these are not field measurements.",
    "questions": [
      {
        "question": "Reproduce the baseline Calculated allowance (psi) without rounding intermediate values.",
        "answer": "4 × 0.052 × 5,000 = 1,040 psi. Calculated allowance (psi) = 1040. The same equivalent density margin represents a different surface pressure at a different shoe depth."
      },
      {
        "question": "Compare the first and last recorded scenarios. Which input changes?",
        "answer": "Shoe TVD (ft) changes from 3000 to 8000. Other controls remain as stated in the premise. Calculated allowance (psi) changes from 624 to 1664."
      },
      {
        "question": "What would be needed to apply this example to a different physical system?",
        "answer": "Replace the synthetic controls with compatible documented inputs and check the relation's assumptions. This is the shoe-based arithmetic allowance, not a complete operational pressure limit. The same equivalent density margin represents a different surface pressure at a different shoe depth."
      }
    ]
  },
  "recorded": null
}