A. Richard Sinclair, Santrol
The oilfield use of resin coating on proppants such as sand, glass beads and ceramics began in the middle 1970's.Applications include downhole use in both onshore and offshore oil and gas wells. The initial idea was to pump a partially cured or curable resin coated proppant (RCP) in frac fluid into a well and let the elevated bottom hole temperature polymerize and bond the phenolic resin particles together. These bonded particles form a downhole filter or sheet of permeable sandstone in the fracture. The earliest use was for sand control where resin coated particles were injected as a gravel pack. In 1976 the resin coated particles were first used as a small tail-in proppant in a hydraulic fracture treatment. Starting with small volumes this use gradually expanded to larger volumes until today large volumes of the frac proppant in many wells are resin coated. Resin coated materials replace both sand and ceramic proppants and have now grown to a frac market of many million pounds per year.