Grease seals for wireline rely on high-viscosity packing injected between flow tubes. The grease forms a viscous barrier around the cable, sealing annular gaps. Multiple flow tubes with close tolerances enhance sealing efficiency. Pressure-balanced grease pumps maintain injection at 1.5 times well pressure. These seals are essential in high-rate gas wells where hydraulic sealing alone... https://globalsealstech.com/product-category/oil-gas-seals/oil-free-lubricated-pump-seals/