"""Pydantic models for Geomechanics calculations."""
from pydantic import BaseModel, Field, field_validator, ConfigDict
from typing import Literal, Union, List, Optional
import numpy as np
class VerticalStressRequest(BaseModel):
"""Request model for vertical stress (overburden) calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"depth": 10000.0,
"water_depth": 0.0,
"avg_density": 144.0,
"water_density": 64.0,
}
}
)
depth: float = Field(..., gt=0, description="True vertical depth below surface (ft)")
water_depth: float = Field(
0.0, ge=0, description="Water depth for offshore wells (ft)"
)
avg_density: float = Field(
144.0, gt=0, le=300, description="Average bulk density of overburden (lb/ft³)"
)
water_density: float = Field(
64.0, gt=0, le=100, description="Water density (lb/ft³) - fresh=62.4, seawater=64.0"
)
class PorePressureEatonRequest(BaseModel):
"""Request model for pore pressure calculation using Eaton's method."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"depth": 10000.0,
"observed_value": 100.0,
"normal_value": 70.0,
"overburden_psi": 10400.0,
"eaton_exponent": 3.0,
"method": "sonic",
}
}
)
depth: float = Field(..., gt=0, description="True vertical depth (ft)")
observed_value: float = Field(
..., gt=0, description="Observed sonic (μs/ft) or resistivity (ohm-m)"
)
normal_value: float = Field(
..., gt=0, description="Normal compaction trend value at this depth"
)
overburden_psi: float = Field(..., gt=0, description="Overburden stress at depth (psi)")
eaton_exponent: float = Field(
3.0, gt=0, le=5, description="Eaton exponent (3.0 for sonic, 1.2 for resistivity)"
)
method: Literal["sonic", "resistivity"] = Field(
"sonic", description="Method type"
)
class EffectiveStressRequest(BaseModel):
"""Request model for effective stress calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"total_stress": 10400.0,
"pore_pressure": 4680.0,
"biot_coefficient": 1.0,
}
}
)
total_stress: Union[float, List[float]] = Field(
..., description="Total stress (psi) - scalar or array"
)
pore_pressure: Union[float, List[float]] = Field(
..., description="Formation pore pressure (psi) - scalar or array"
)
biot_coefficient: float = Field(
1.0, gt=0, le=1, description="Biot's coefficient (0.6-1.0 for most rocks)"
)
class HorizontalStressRequest(BaseModel):
"""Request model for horizontal stress calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"vertical_stress": 10400.0,
"pore_pressure": 4680.0,
"poisson_ratio": 0.25,
"tectonic_factor": 0.0,
"biot_coefficient": 1.0,
}
}
)
vertical_stress: float = Field(..., gt=0, description="Total vertical stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
poisson_ratio: float = Field(
..., gt=0, lt=0.5, description="Poisson's ratio (0.15-0.40 typical)"
)
tectonic_factor: float = Field(
0.0, ge=0, le=1, description="Tectonic stress multiplier (0=passive, 0.5=strike-slip, 1.0=reverse)"
)
biot_coefficient: float = Field(
1.0, gt=0, le=1, description="Biot's coefficient"
)
class ElasticModuliRequest(BaseModel):
"""Request model for elastic moduli conversion (provide any 2)."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"youngs_modulus": 1000000.0,
"poisson_ratio": 0.25,
}
}
)
youngs_modulus: Optional[float] = Field(None, gt=0, description="Young's modulus E (psi)")
bulk_modulus: Optional[float] = Field(None, gt=0, description="Bulk modulus K (psi)")
shear_modulus: Optional[float] = Field(None, gt=0, description="Shear modulus G (psi)")
poisson_ratio: Optional[float] = Field(None, gt=-1, lt=0.5, description="Poisson's ratio ν")
lame_parameter: Optional[float] = Field(None, description="Lamé's first parameter λ (psi)")
@field_validator("poisson_ratio")
@classmethod
def validate_poisson(cls, v):
"""Validate Poisson's ratio for physical bounds."""
if v is not None and (v < 0 or v >= 0.5):
raise ValueError("Poisson's ratio must be between 0 and 0.5 for stable materials")
return v
class RockStrengthRequest(BaseModel):
"""Request model for rock strength calculation using Mohr-Coulomb."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"cohesion": 500.0,
"friction_angle": 30.0,
"effective_stress_min": 2000.0,
}
}
)
cohesion: float = Field(..., ge=0, description="Rock cohesion (psi)")
friction_angle: float = Field(
..., gt=0, lt=90, description="Internal friction angle (degrees, 20-40° typical)"
)
effective_stress_min: float = Field(
..., ge=0, description="Minimum effective principal stress (psi)"
)
class DynamicToStaticRequest(BaseModel):
"""Request model for dynamic to static moduli conversion."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"dynamic_youngs": 1500000.0,
"dynamic_poisson": 0.20,
"correlation": "eissa_kazi",
"lithology": "sandstone",
}
}
)
dynamic_youngs: Optional[float] = Field(None, gt=0, description="Dynamic Young's modulus (psi)")
dynamic_poisson: Optional[float] = Field(None, gt=0, lt=0.5, description="Dynamic Poisson's ratio")
correlation: Literal["eissa_kazi", "plona_cook", "linear"] = Field(
"eissa_kazi", description="Correlation method"
)
lithology: Literal["sandstone", "shale", "carbonate"] = Field(
"sandstone", description="Rock lithology"
)
class BreakoutWidthRequest(BaseModel):
"""Request model for borehole breakout width calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"pore_pressure": 4680.0,
"mud_weight": 9.0,
"wellbore_azimuth": 45.0,
"ucs": 3000.0,
"friction_angle": 30.0,
}
}
)
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
mud_weight: float = Field(..., gt=0, description="Drilling fluid density (ppg)")
wellbore_azimuth: float = Field(
..., ge=0, le=360, description="Well azimuth (degrees, 0-360)"
)
ucs: float = Field(..., gt=0, description="Unconfined compressive strength (psi)")
friction_angle: float = Field(
..., gt=0, lt=90, description="Internal friction angle (degrees)"
)
class FractureGradientRequest(BaseModel):
"""Request model for fracture gradient calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"depth": 10000.0,
"vertical_stress": 10400.0,
"pore_pressure": 4680.0,
"poisson_ratio": 0.25,
"method": "eaton",
}
}
)
depth: float = Field(..., gt=0, description="True vertical depth (ft)")
sigma_h_min: Optional[float] = Field(None, gt=0, description="Minimum horizontal stress (psi) if known")
vertical_stress: float = Field(..., gt=0, description="Overburden stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
poisson_ratio: float = Field(
0.25, gt=0, lt=0.5, description="Poisson's ratio for estimation methods"
)
method: Literal["hubbert_willis", "eaton", "matthews_kelly"] = Field(
"eaton", description="Calculation method"
)
class MudWeightWindowRequest(BaseModel):
"""Request model for safe mud weight window calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"pore_pressure": 4680.0,
"fracture_pressure": 7800.0,
"depth": 10000.0,
"safety_margin_overbalance": 0.5,
"safety_margin_fracture": 0.5,
}
}
)
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
fracture_pressure: float = Field(..., gt=0, description="Formation fracture pressure (psi)")
depth: float = Field(..., gt=0, description="True vertical depth (ft)")
collapse_pressure: Optional[float] = Field(None, gt=0, description="Collapse pressure for stability (psi)")
safety_margin_overbalance: float = Field(
0.5, ge=0, description="Overbalance safety margin (ppg)"
)
safety_margin_fracture: float = Field(
0.5, ge=0, description="Fracture safety margin (ppg)"
)
class CriticalMudWeightRequest(BaseModel):
"""Request model for critical mud weight to prevent collapse."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"pore_pressure": 4680.0,
"cohesion": 500.0,
"friction_angle": 30.0,
"wellbore_azimuth": 45.0,
"wellbore_inclination": 0.0,
"depth": 10000.0,
}
}
)
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
cohesion: float = Field(..., ge=0, description="Rock cohesion (psi)")
friction_angle: float = Field(..., gt=0, lt=90, description="Internal friction angle (degrees)")
wellbore_azimuth: float = Field(
..., ge=0, le=360, description="Well azimuth (degrees)"
)
wellbore_inclination: float = Field(
0.0, ge=0, le=90, description="Well deviation from vertical (degrees)"
)
depth: float = Field(..., gt=0, description="True vertical depth (ft)")
class ReservoirCompactionRequest(BaseModel):
"""Request model for reservoir compaction calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"pressure_drop": 1000.0,
"reservoir_thickness": 100.0,
"youngs_modulus": 500000.0,
"poisson_ratio": 0.25,
"biot_coefficient": 1.0,
}
}
)
pressure_drop: float = Field(..., gt=0, description="Reservoir pressure depletion (psi)")
reservoir_thickness: float = Field(..., gt=0, description="Net pay thickness (ft)")
pore_compressibility: Optional[float] = Field(
None, gt=0, description="Pore compressibility (1/psi) if known"
)
bulk_compressibility: Optional[float] = Field(
None, gt=0, description="Bulk compressibility (1/psi) if known"
)
youngs_modulus: float = Field(..., gt=0, description="Static Young's modulus (psi)")
poisson_ratio: float = Field(..., gt=0, lt=0.5, description="Poisson's ratio")
biot_coefficient: float = Field(
1.0, gt=0, le=1, description="Biot coefficient"
)
class PoreCompressibilityRequest(BaseModel):
"""Request model for pore volume compressibility calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"porosity": 0.20,
"youngs_modulus": 500000.0,
"poisson_ratio": 0.25,
"grain_compressibility": 3e-7,
}
}
)
bulk_compressibility: Optional[float] = Field(
None, gt=0, description="Rock bulk compressibility (1/psi)"
)
grain_compressibility: float = Field(
3e-7, gt=0, description="Grain compressibility (1/psi, default 3e-7)"
)
porosity: float = Field(..., gt=0, lt=1, description="Formation porosity (fraction 0-1)")
youngs_modulus: Optional[float] = Field(None, gt=0, description="Young's modulus for calculating Cb (psi)")
poisson_ratio: Optional[float] = Field(None, gt=0, lt=0.5, description="Poisson's ratio for calculating Cb")
class LeakOffPressureRequest(BaseModel):
"""Request model for leak-off test analysis."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"leak_off_pressure": 2500.0,
"mud_weight": 9.0,
"test_depth": 10000.0,
"pore_pressure": 4680.0,
"test_type": "LOT",
}
}
)
leak_off_pressure: float = Field(..., gt=0, description="LOT pressure at surface (psi)")
mud_weight: float = Field(..., gt=0, description="Mud weight during test (ppg)")
test_depth: float = Field(..., gt=0, description="True vertical depth of test (ft)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure at test depth (psi)")
test_type: Literal["LOT", "FIT"] = Field(
"LOT", description="Test type - LOT (leak-off) or FIT (integrity test)"
)
class FractureWidthRequest(BaseModel):
"""Request model for hydraulic fracture width calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"net_pressure": 500.0,
"fracture_height": 100.0,
"fracture_half_length": 500.0,
"youngs_modulus": 1000000.0,
"poisson_ratio": 0.25,
"model": "PKN",
}
}
)
net_pressure: float = Field(..., gt=0, description="Net treating pressure (psi) = Pfrac - σh_min")
fracture_height: float = Field(..., gt=0, description="Fracture height (ft), typically ≈ pay thickness")
fracture_half_length: float = Field(..., gt=0, description="Fracture half-length (ft), one wing")
youngs_modulus: float = Field(..., gt=0, description="Formation Young's modulus (psi)")
poisson_ratio: float = Field(..., gt=0, lt=0.5, description="Poisson's ratio")
model: Literal["PKN", "KGD"] = Field("PKN", description="Fracture model")
# ============================================================================
# NEW ADVANCED GEOMECHANICS MODELS
# ============================================================================
class StressPolygonRequest(BaseModel):
"""Request model for stress polygon analysis (allowable stress states)."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"vertical_stress": 10000.0,
"pore_pressure": 4500.0,
"friction_coefficient": 0.6,
"sigma_h_min": 6500.0,
"sigma_h_max": 8500.0,
}
}
)
vertical_stress: float = Field(..., gt=0, description="Vertical stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Pore pressure (psi)")
friction_coefficient: float = Field(
0.6, gt=0, lt=1.5, description="Fault friction coefficient (0.6-0.85 typical)"
)
sigma_h_min: Optional[float] = Field(None, gt=0, description="Actual min horizontal stress to plot (psi)")
sigma_h_max: Optional[float] = Field(None, gt=0, description="Actual max horizontal stress to plot (psi)")
class SandProductionRequest(BaseModel):
"""Request model for sand production prediction (critical drawdown/velocity)."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"pore_pressure": 4500.0,
"ucs": 3000.0,
"cohesion": 500.0,
"friction_angle": 30.0,
"wellbore_radius": 0.354,
"perforation_depth": 0.5,
"permeability": 100.0,
"porosity": 0.20,
}
}
)
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
ucs: float = Field(..., gt=0, description="Unconfined compressive strength (psi)")
cohesion: float = Field(..., ge=0, description="Rock cohesion (psi)")
friction_angle: float = Field(..., gt=0, lt=90, description="Internal friction angle (degrees)")
wellbore_radius: float = Field(0.354, gt=0, description="Wellbore radius (ft) - default 8.5 inch hole")
perforation_depth: float = Field(0.5, gt=0, description="Perforation tunnel depth (ft)")
permeability: float = Field(..., gt=0, description="Formation permeability (mD)")
porosity: float = Field(..., gt=0, lt=1, description="Formation porosity (fraction)")
class FaultStabilityRequest(BaseModel):
"""Request model for fault stability analysis (Coulomb failure stress)."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_1": 10000.0,
"sigma_3": 6000.0,
"pore_pressure": 4500.0,
"fault_strike": 45.0,
"fault_dip": 60.0,
"sigma_1_azimuth": 0.0,
"friction_coefficient": 0.6,
"cohesion": 0.0,
}
}
)
sigma_1: float = Field(..., gt=0, description="Maximum principal stress (psi)")
sigma_3: float = Field(..., gt=0, description="Minimum principal stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Pore pressure (psi)")
fault_strike: float = Field(..., ge=0, le=360, description="Fault strike azimuth (degrees)")
fault_dip: float = Field(..., gt=0, le=90, description="Fault dip angle (degrees from horizontal)")
sigma_1_azimuth: float = Field(0.0, ge=0, le=360, description="σ1 azimuth (degrees from North)")
friction_coefficient: float = Field(0.6, gt=0, lt=1.5, description="Fault friction coefficient")
cohesion: float = Field(0.0, ge=0, description="Fault cohesion (psi) - typically 0 for reactivation")
class DeviatedWellStressRequest(BaseModel):
"""Request model for stress transformation to deviated wellbore."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_v": 10000.0,
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"sigma_h_max_azimuth": 45.0,
"well_azimuth": 90.0,
"well_inclination": 60.0,
"pore_pressure": 4500.0,
"mud_weight": 10.0,
"depth": 10000.0,
}
}
)
sigma_v: float = Field(..., gt=0, description="Vertical stress (psi)")
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
sigma_h_max_azimuth: float = Field(..., ge=0, le=360, description="σH_max azimuth from North (degrees)")
well_azimuth: float = Field(..., ge=0, le=360, description="Well azimuth from North (degrees)")
well_inclination: float = Field(..., ge=0, le=90, description="Well inclination from vertical (degrees)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
mud_weight: float = Field(..., gt=0, description="Drilling fluid density (ppg)")
depth: float = Field(..., gt=0, description="True vertical depth (ft)")
class TensileFailureRequest(BaseModel):
"""Request model for tensile failure and breakdown pressure prediction."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"pore_pressure": 4500.0,
"tensile_strength": 500.0,
"thermal_stress": 0.0,
}
}
)
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
tensile_strength: float = Field(0.0, ge=0, description="Rock tensile strength (psi) - often ~UCS/10")
thermal_stress: float = Field(0.0, description="Thermal stress contribution (psi) - negative for cooling")
class ShearFailureCriteriaRequest(BaseModel):
"""Request model for multiple shear failure criteria comparison."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_1": 10000.0,
"sigma_2": 7500.0,
"sigma_3": 5000.0,
"ucs": 8000.0,
"cohesion": 1500.0,
"friction_angle": 30.0,
"criteria": ["mohr_coulomb", "drucker_prager", "mogi_coulomb"],
}
}
)
sigma_1: float = Field(..., description="Maximum principal stress (psi)")
sigma_2: float = Field(..., description="Intermediate principal stress (psi)")
sigma_3: float = Field(..., ge=0, description="Minimum principal stress (psi)")
ucs: float = Field(..., gt=0, description="Unconfined compressive strength (psi)")
cohesion: float = Field(..., ge=0, description="Rock cohesion (psi)")
friction_angle: float = Field(..., gt=0, lt=90, description="Internal friction angle (degrees)")
criteria: List[Literal["mohr_coulomb", "drucker_prager", "mogi_coulomb", "modified_lade", "modified_wiebols"]] = Field(
["mohr_coulomb", "drucker_prager", "mogi_coulomb"],
description="List of failure criteria to evaluate"
)
class BreakoutStressInversionRequest(BaseModel):
"""Request model for stress estimation from observed breakout width."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"breakout_width": 60.0,
"sigma_v": 10000.0,
"pore_pressure": 4500.0,
"mud_weight": 10.0,
"ucs": 5000.0,
"friction_angle": 30.0,
"depth": 10000.0,
}
}
)
breakout_width: float = Field(..., gt=0, lt=180, description="Observed breakout angular width (degrees)")
sigma_v: float = Field(..., gt=0, description="Vertical stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
mud_weight: float = Field(..., gt=0, description="Drilling fluid density during observation (ppg)")
ucs: float = Field(..., gt=0, description="Unconfined compressive strength (psi)")
friction_angle: float = Field(..., gt=0, lt=90, description="Internal friction angle (degrees)")
depth: float = Field(..., gt=0, description="True vertical depth (ft)")
class BreakdownPressureRequest(BaseModel):
"""Request model for formation breakdown pressure calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"pore_pressure": 4500.0,
"tensile_strength": 500.0,
"poroelastic_constant": 0.0,
}
}
)
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
pore_pressure: float = Field(..., gt=0, description="Formation pore pressure (psi)")
tensile_strength: float = Field(0.0, ge=0, description="Rock tensile strength (psi)")
poroelastic_constant: float = Field(
0.0, ge=0, le=1.0,
description="Poroelastic constant η = α(1-2ν)/(1-ν), typically 0-0.5"
)
class StressPathRequest(BaseModel):
"""Request model for stress path analysis during depletion/injection."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"initial_pore_pressure": 5000.0,
"final_pore_pressure": 3000.0,
"vertical_stress": 10000.0,
"initial_sigma_h": 7000.0,
"poisson_ratio": 0.25,
"biot_coefficient": 1.0,
"stress_path_coefficient": 0.67,
}
}
)
initial_pore_pressure: float = Field(..., gt=0, description="Initial formation pore pressure (psi)")
final_pore_pressure: float = Field(..., gt=0, description="Final formation pore pressure (psi)")
vertical_stress: float = Field(..., gt=0, description="Vertical stress - assumed constant (psi)")
initial_sigma_h: float = Field(..., gt=0, description="Initial horizontal stress (psi)")
poisson_ratio: float = Field(..., gt=0, lt=0.5, description="Poisson's ratio")
biot_coefficient: float = Field(1.0, gt=0, le=1, description="Biot coefficient")
stress_path_coefficient: Optional[float] = Field(
None, gt=0, lt=1,
description="Stress path coefficient γ = Δσh/ΔPp. If not provided, calculated from ν"
)
class ThermalStressRequest(BaseModel):
"""Request model for thermal stress effects calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"temperature_change": -50.0,
"youngs_modulus": 1000000.0,
"poisson_ratio": 0.25,
"thermal_expansion_coefficient": 6e-6,
"biot_coefficient": 1.0,
}
}
)
temperature_change: float = Field(
..., description="Temperature change (degF) - negative for cooling, positive for heating"
)
youngs_modulus: float = Field(..., gt=0, description="Young's modulus (psi)")
poisson_ratio: float = Field(..., gt=0, lt=0.5, description="Poisson's ratio")
thermal_expansion_coefficient: float = Field(
6e-6, gt=0, description="Linear thermal expansion coefficient (1/degF) - typical 5-8e-6"
)
biot_coefficient: float = Field(1.0, gt=0, le=1, description="Biot coefficient")
class UCSFromLogsRequest(BaseModel):
"""Request model for UCS estimation from well logs."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sonic_dt": 70.0,
"porosity": 0.15,
"youngs_modulus": 2000000.0,
"lithology": "sandstone",
"correlation": "mcnally",
}
}
)
sonic_dt: Optional[float] = Field(None, gt=0, description="Sonic transit time (μs/ft)")
porosity: Optional[float] = Field(None, gt=0, lt=1, description="Porosity (fraction)")
youngs_modulus: Optional[float] = Field(None, gt=0, description="Young's modulus (psi)")
lithology: Literal["sandstone", "shale", "carbonate", "general"] = Field(
"sandstone", description="Rock lithology for correlation selection"
)
correlation: Literal["mcnally", "horsrud", "chang", "lal", "vernik"] = Field(
"mcnally", description="UCS correlation to use"
)
class CriticalDrawdownRequest(BaseModel):
"""Request model for critical drawdown pressure calculation."""
model_config = ConfigDict(
json_schema_extra={
"example": {
"sigma_h_max": 8500.0,
"sigma_h_min": 6500.0,
"reservoir_pressure": 5000.0,
"ucs": 3000.0,
"cohesion": 500.0,
"friction_angle": 30.0,
"wellbore_radius": 0.354,
}
}
)
sigma_h_max: float = Field(..., gt=0, description="Maximum horizontal stress (psi)")
sigma_h_min: float = Field(..., gt=0, description="Minimum horizontal stress (psi)")
reservoir_pressure: float = Field(..., gt=0, description="Initial reservoir pressure (psi)")
ucs: float = Field(..., gt=0, description="Unconfined compressive strength (psi)")
cohesion: float = Field(..., ge=0, description="Rock cohesion (psi)")
friction_angle: float = Field(..., gt=0, lt=90, description="Internal friction angle (degrees)")
wellbore_radius: float = Field(0.354, gt=0, description="Wellbore radius (ft)")
