Hydraulic Holelock for Coupling

Hydraulic holelock for seismometer coupling

Hydraulic holelock for low and high temperature applications.

Holelock devices may be used to couple sensors at specific depths in boreholes for either short or longer term measurements (<2 years). The simple hydraulic components provide reliability and high coupling force. Holelock components are project specific and will have specifications dependent on the seismometers used, temperatures, casing materials and other factors. The weight of these systems depends on the depth of the deployment but usually requires a crane, winch and reel stands for installation. Specifications below are given for two example scenarios.

Features:

• Customizable holelock arm

• Withstands installations up to 150 °C and ca. 1,000 m depth

• Serviceable double-acting hydraulic system

• 3 points of contact for maximum coupling

• Potential for multiple holelocks/sensors per hole

Holelock Parameters:

• Material: SS 316L

• Weight: 20 kg (excluding oil-charged hose)

• Minimum borehole diameter: 101.6 mm / 4 inch ID

• Length: 706 mm

• Hydraulic cylinder pressure rating: 34.5 MPa

Hydraulic Line Parameters:

Low temperature, 450 m depth

• Material: Thermoplastic and Aramid

• Maximum Temperature: 100°C

• Working Pressure: 34.5 Mpa

High temperature, 450 m depth

• Material: PTFE and SS

• Maximum Temperature: 100°C

• Working Pressure: 34.5 Mpa

Surface Components:

A typical setup is a combination of the following elements:

• Double-acting pump

• Nitrogen reservoir

• Pressure gauges and valves

• Submerged return lines and oil cooling