Analysis of DST flow data with Ramey type curves

Input(s)

\(\mathrm{p}_{\mathrm{i}}\): Initial Pressure \((\mathrm{psi})\)

\(\mathrm{p}_{\mathrm{wf}}\): Well Flowing Pressure (psi)

\(\mathrm{p}_{\mathrm{o}}\): Pressure at Time \(T=0\) (psi)

Ø: Porosity (dimensionless)

\(c_{\mathrm{t}}\): Total Compressibility \((1 / \mathrm{psi})\)

\(\mathrm{h}\): Formation Thickness (ft)

C: Wellbore Storage Coefficient (bbl/psi)

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

\(\mu\): Viscosity \((\mathrm{cP})\)

\(\mathrm{t}_{\mathrm{c}}\): Dimensionless Parameter from Curve Fitting as \(\frac{T_{d}}{c_{d}}\) (dimensionless)

\(\mathrm{t}\): Time (h)

CES: Match Point for Dimensionless Well Bore Coefficient from Curve as (Cd E (2 s))_(mp) (dimensionless)

Output(s)

\(\mathrm{p}_{\mathrm{DR}}\): Dimensionless Pressure (dimensionless)

\(\mathrm{q}_{\mathrm{DR}}\): Dimensionless Flow Rate (dimensionless)

\(\mathrm{C}_{\mathrm{D}}\): Dimensionless Well Bore Storage Coefficient (dimensionless)

\(\mathrm{k}\): Permeability \((\mathrm{mD})\)

s: Skin Factor (dimensionless)

Formula(s)

Reference(s)

Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of Petroleum Engineers, Page: 155.