What is the term used to describe the pressure that is required at the rock face to open a fracture?

What is the term used to describe the pressure that is required at the rock face to open a fracture?

• A. Fracture initiation Pressure
• B. Break-down Pressure
• C. Fracture Propagation Pressure
• D. Fracture Closure Pressure

Answer: (A)

The key idea is the threshold at which the rock first starts to crack open under the injected fluid. When the fluid pressure surpasses the rock’s strength at the rock face, microcracks initiate and a fracture begins to form. That initial opening pressure is called fracture initiation pressure. It marks the transition from purely elastic response to the onset of fracture creation. Once the fracture has initiated, higher pressures are needed to drive the fracture to grow further—this is fracture propagation pressure. The fracture can close again if the pressure drops below the rock’s ability to keep it open, which is described by fracture closure pressure. Sometimes people use break-down pressure to refer to the same opening threshold, but the term that directly describes the moment the fracture first opens is fracture initiation pressure.

The key idea is the threshold at which the rock first starts to crack open under the injected fluid. When the fluid pressure surpasses the rock’s strength at the rock face, microcracks initiate and a fracture begins to form. That initial opening pressure is called fracture initiation pressure. It marks the transition from purely elastic response to the onset of fracture creation.

Once the fracture has initiated, higher pressures are needed to drive the fracture to grow further—this is fracture propagation pressure. The fracture can close again if the pressure drops below the rock’s ability to keep it open, which is described by fracture closure pressure. Sometimes people use break-down pressure to refer to the same opening threshold, but the term that directly describes the moment the fracture first opens is fracture initiation pressure.