Stop Erosion at the Well Head on Fractured Wells

Abstract

Shale gas and other wells commonly suffer from severe erosion caused by frac sand and other residual solids that routinely appear at the well head and due to their abrasiveness can cause severe erosion in well-head equipment. In particular, it is not uncommon for well head let-down valves (flow line chokes) to require replacement after only a few months of service. In addition to erosion issues, the solids accumulate in downstream flow-lines and process equipment and cause blockages and other operation problems until the solids are removed. This paper describes how Todd Energy stopped their well head sand accumulation and potential choke and pipework erosion by installing a custom designed Well Head Desander directly at the well head. Before installation Todd Energy had a duplex sand filter that required significant manual intervention to switch filters and empty. Todd Energy approached Process Group for a long-term solution. Process Group custom designed a Well Head Desander to withstand the highly abrasive environment experienced at the well head so that the solids could be removed from the well fluids upstream of the flow-line choke valve. The custom designed package included a solids accumulation vessel to allow the captured solids to be collected and stored for batch dumping for disposal at regular intervals without stopping the gas flow from the well. Plant data shows that the Well Head Desander Unit consistently removes frac sand (typically >0.5 mm diameter) and other solids that are produced from the well. The Desander remains in continuous operation and biannual maintenance inspections confirm no erosion issues either in the Desander or with downstream equipment.