1. n. [Well Completions]

The pressure at which a treatment or test fluid can be injected into the formation matrix without causing a breakdown, or fracture, of the rock matrix. The injection pressure is commonly described as the surface pump pressure required to achieve injection. However, since the hydrostatic pressure of the fluid column also contributes to the downhole pressure value, the downhole pressure should also be considered.

See: hydrostatic pressure

2. n. [Production Testing]

The pressure needed to inject fluid into the formation to pressurize or displace hydrocarbons.

See: hydrocarbon