Diagnostics Functions - Petroleum Office

Calculates instantaneous decline rate D(t) for Ansah-Knowles-Buba (2000) decline, [1/T]. Computed numerically.

Calculates instantaneous decline rate D(t) for Arps decline, [1/T]. D(t) = Di/(1+b×Di×t). Computed numerically.

Computes the beta diagnostic β = t×D(t) for flow regime identification. β≈0.5: linear flow, β≈0.25: bilinear, β≈1.0: boundary-dominated.

Calculates the Bourdet (smoothed) derivative at point t. Used for flow regime identification and production diagnostics.

Computes the time-varying Arps b-parameter. b=0: exponential, 0<b<1: hyperbolic, b=1: harmonic, b>1: transient (unconventional).

Calculates instantaneous decline rate D(t) for Duong model, [1/T]. Computed numerically.

Calculates instantaneous decline rate D(t) for Extended Exponential Decline Model (EEDM), [1/T]. Computed analytically.

Calculates instantaneous decline rate D(t) for Logistic Growth Model (LGM), [1/T]. Computed analytically.

Calculates instantaneous decline rate D(t) for Modified Hyperbolic decline, [1/T]. Computed numerically.

Calculates instantaneous decline rate D(t) for Power Law Exponential (PLE) model, [1/T]. D(t) = D∞ + n×Di0×t^(n-1). Computed numerically.

Calculates instantaneous decline rate D(t) for Stretched Exponential model, [1/T]. D(t) = (n/τ)×(t/τ)^(n-1). Computed numerically.

Calculates instantaneous decline rate D(t) for Transient Hyperbolic Model, [1/T]. Computed analytically.