Sand production in oil and gas producing wells can cause rapid erosion and wear of top side equipment such as chokes, valves, and flow-lines. The areas that can experience the most severe effects of erosion are immediately downstream of a choke, outer diameters of bends, reducers, misaligned flange joints and pipe T joints.
Early detection of erosion is key to prevent serious damage and to prevent safety risks from potential leaks or malfunction of process equipment. The Sand Probe is a sacrificial tube inserted into the flow and can be used as and early warning (safety) device for alerting the operator that a critical metal loss (erosion) has occurred due to the effects of sand or solids erosion in the flow.
Cosasco Sand Probes were developed as a simple and robust means of detecting significant erosion in high-velocity flow lines. This new design replaces the older NPT sacrificial tube and side T access fitting system. The advantages are that the side T fitting and injection nut/seal assembly is no longer required and the new probe design offers a more robust probe with a more reliable mechanical connection. The modified hollow plug assembly allows online retrieval to be achieved.
The sensing portion of the Sand Probe is basically a reinforced sacrificial tube made from corrosion resistant material (SS316). The probe is connected to a hollow plug assembly which contains a needle valve that isolates the pressure in the event of the tube being eroded. This allows the external gauge assembly to be removed for live retrieval of probe using a Cosasco retrieval tool. The Sand Probe can be to be used in any standard Cosasco 2” Access Fitting Assembly.
In use, providing there is sufficient flow velocity, the effect of sand or solids will eventually erode through the Sand Probe sacrificial tube portion, exposing the sealed system to the working pressure of the line. The pressure is then directed through ports in the Hollow Plug and through an nipple to register upon a Pressure Gauge Assembly.