Development of a method for removing mechanical impurities from well surfaces with intense sand ingress

In Azerbaijan, most of the hydrocarbon reserves are confined to fields with uncemented and weakly cemented formations. The operation of wells in these fields is accompanied by intense sand ingress, which prevents fluid flow from the reservoir to the well and leads to a reduction in oil production rates. Many methods are used to control sand ingress, such as the treatment of the wellbore bottom zone with chemical compositions, the installation of anti-sand filters of various designs. However, despite the effectiveness of these methods, sand continues to enter wells exploiting uncapped reservoirs in significant quantities. A significant amount of sand particles and mechanical impurities are carried into the well and settle downhole, forming sand plugs. Over time, these sand plugs become thicker and harder to penetrate, making it more difficult for hydrocarbons to flow into the well and, in some cases, leading to a complete shut-in of the well. One of the most effective methods of removing sand from wells is the sand plug washing process. The selection of washing fluid is critical to the success of the sand plug washing process. To this end, studies have been carried out to develop a composition containing the following surfactants. A sand plug washing composition has been developed containing anionic surfactant as a foaming agent, aluminium nanoparticles with a size of 50-70 nm, air as a gas phase and seawater or industrial water. Keywords: well; mechanical impurities; sand ingress; sand plug; washing; washing fluid; surfactants; aluminium nanoparticles; degree of aeration.