S-well Inflow Calculator

Complex-Trajectory Well Productivity Evaluation — Segmented Approach (Dupuit / Joshi)

⚠ One or more layers: Joshi denominator ≤ 0 (L ≫ h at low kv/kh). Fallback to Dupuit applied (marked Joshi*).

⚠ Friction-limited wellbore: wellbore pressure exceeds reservoir pressure in one or more intervals. Inflow from those zones = 0. This is physically consistent — increase wellbore diameter or reduce production rate.

ℹ Wellbore flow regime — laminar (Re < 2300). At this rate, pipe roughness does not affect pressure losses (f = 64/Re). For noticeable friction effects, Q must exceed — STB/d.

Fluid and Wellbore Parameters

Viscosity (cp)

Formation Volume Factor B

Wellbore Radius rw (ft)

Drainage Radius Re (ft)

Heel BHP (psi)

Wellbore Diameter (in)

Oil Density (lb/ft³)

Pipe Roughness (in)

Well Trajectory

Section	Length (ft)	Angle In (°)	Angle Out (°)

Productive Layers

Name	Top TVD (ft)	Bottom TVD (ft)	k (mD)	kv/kh	Pres (psi)	S_mech

Perforation Intervals

Name	Top TVD (ft)	Bottom TVD (ft)

Results

Traditional Method (Dupuit / Joshi • S_mech only • no friction losses)

Layer	Model	Angle (°)	Contact (ft)	S_mech	ΔP (psi)	Rate (STB/d)	Share (%)	Dev. from Seg. (%)
Click 'Calculate'

Total Rate (trad.): — STB/d | Dev. from Seg.: —

Segmented Approach (S_theta + S_p + S_mech • pressure profile)

Layer	Model	Angle (°)	Contact (ft)	hp (ft)	S_mech	S_theta	S_p	S_total	Local Pwf (psi)	Drawdown (psi)	Rate (STB/d)	Share (%)
Click 'Calculate'

Total Rate (seg.): — STB/d | Re at Heel: — | Flow Regime: —