Vertical well critical rate correlations - Craft and Hawkins method

Input(s)

b: Penetration Ratio, \(\left(h_{p} / \mathrm{h}\right)\) (dimensionless)

\(r_{e}\): Radius of Drainage \((\mathrm{ft})\)

\(r_{w}\): Radius of Wellbore \((\mathrm{ft})\)

\(h_{p}\): Thickness of Perforated interval (ft)

\(\mathrm{h}\): Oil Column Thickness (ft)

\(\mu_{o}\): Oil Viscosity \((\mathrm{cP})\)

\(B_{o}\): Oil Formation Volume Factor (RB/STB)

\(k_{o}\): Effective Oil Permeability \((\mathrm{mD})\)

\(p_{w s}\): Static Well Pressure Corrected to the Middle of the Producing Interval (psi)

\(p_{w f}\): Flowing Well Pressure at the Middle of the Producing Interval (psi)

Output(s)

PR: Productivity Ratio (dimensionless)

\(q_{o}\): Critical Rate (Maximum Oil Rate without Coning) (STB/day)

Formula(s)

Reference(s)

Joshi, S. D. 1991, Horizontal Well Technology. Tulsa, Oklahoma: PennWell Publishing Company. Chapter: 8 , Page: 254.