Motivation
Changing production (or injection) rate is leading to pressure response which depends on the properties of connected beddings.
This gives an idea of assessing formation properties by analysing a pressure transition from one flow regime to another and which is called Pressure Transient Analysis.
Definition
Pressure Transient survey (PTA) is
Drawdown survey (DD) is
Build-up survey (BUS) is
Fall off survey (FOS) is
Objectives
| Primary deliverables | Conditional Deliverables | |||
|---|---|---|---|---|
| 1 | Assess current formation pressure | p_e | ||
| 3 | Assess skin-factor | S | Assess formation damage Assess formation penetration Identify fracture-network development around the well | |
| 4 | Assess formation transmissibility | \sigma | Assess permeability k assuming flowing thickness h is known Assess flowing thickness h assuming permeability k is known Assess water-oil column assuming permeability k and flowing thickness h are both known | |
| 5 | Assess minimum drainable volume around the well | V_\phi | Assess minimum hydrocarbon reserves around the well Assess drainage area A around the well assuming flowing thickness h is known Assess flowing thickness h assuming the drainage area A around the well is known | |
| 6 | Identify boundary type PSS, \, SS, \, BAFFLE and assess its proximity r_e | |||
| 7 | Identify fracture presence and assess its size X_f | |||
| 8 | Assess the fracture opening threshold \delta P_{X_f} | |||
| 9 | Assess the presence r_{ext} of remote reservoir composition areas and its transmissibility \sigma_{ext} | Pick up the channel size/proximity Pick up the oil-water front and its proximity Pick up the oil-gas front and its proximity |