Abstract
Sand flowback can be a big problem in high rate gas wells. Sand can quickly erode chokes, valves and other surface equipment creating potentially dangerous situations for the gas well operating and pipeline companies.
In 1998 and 1999 several different sand flowback or backflow control methods have been applied in Columbia Gas Transmission Company’s Rockport Storage Field. Deformable particles are the latest innovation for controlling sand flowback. Unlike curable resin coated sands and tacky surface-modification agents, deformable particles differ in that they do not "glue" the sand pack in place, but rather mechanically hold it together by dimpling under stress and physically holding adjacent grains of sand firmly in place. A modest weight percentage of deformable particles can easily lock the sand pack in place, resisting the forces brought to bear by gas and fluid flow within the fracture.
The Oriskany Sandstone in the Rockport Storage Field can be classified as a highly permeable formation capable of a withdrawal rate greater than 40 MMSCFD. Stimulation treatments are routinely pumped to improve the Oriskany’s deliverability back to original levels following workover operations. Prior to running deformable particles for sand flowback control, tacky resin-like chemicals and curable resin coated sand were pumped to alleviate the problem.
