A high-stress tri-axial cell with pore pressure for measuring rock properties and simulating hydraulic fracturing

• We constructed a high-stress cell that can accommodate anisotropic stresses and acoustic transducers.
• Wedged spacers embedded with O-seals maintain the pore pressure in the cell.
• Acoustic transducers are placed in an array inside the sample.
• Flat jacks are designed to reduce stress concentrations.
• Simulations using the designed cell provide reasonable results.

A high-stress tri-axial cell that can accommodate pore pressures was designed to simulate hydraulic fracturing processes in the laboratory. The cell can maintain its integrity and causes negligible deformations up to 100 MPa, providing sufficient precision for measuring rock properties and simulating hydraulic fracturing under reservoir conditions. Wedged spacers embedded with O-seals provide the pore pressure inside the cell. Special considerations are taken to avoid stress concentrations, including tapering the flat jacks to ensure uniform stresses on the sample. Acoustic sensors can be attached to the samples to detect acoustic emission signals. Simulations using the designed cell were performed and provided reasonable results.