Definition - What does Sock Filter mean?
Sock Filter, also known as Oil Sock, is a large bag that has a shape just like a human sock and is used to capture silica dust during the fracking process. The filter socks are commonly found in oil and gas drilling sites near the rig or process equipment used to perform the fracking process. In order to abide by the HSE policy of an E&P organization and environmental laws of state, filter socks need to be disposed of as per the rules for disposing radioactive materials.
Petropedia explains Sock Filter
When a drilling activity takes place, a lot of wastewater is used to break apart the shale deep beneath the earth's surface. Once the breaking is done, this wastewater comes back up to the rig. Sock Filter or Oil Socks, are useful at this stage as they filter out the solids that come up with the wastewater. The wastewater needs to be treated further and cleaned after any drilling operation in order to dispose it off safely or use it for further operational processes. The chemical additives and other harmful additives are removed from this water. The wastewater may include high levels of salt, metals, organic compounds, and naturally occurring radioactive materials (NORM).