The technologies of water well repair and rehabilitation

Summary

The share of underground water used for domestic and industrial water supply is more than 60–70% of the total water supply in most constituent entities. For drinking water supply wells up to 200–500 m deep are used; for the sources of mineral and medicinal-table water wells up to 1000–1500 m deep are used. To supply the systems of oil-field reservoir pressure maintenance with water the wells of several kilometers depth are required. The share of inactive wells often exceeds 50%. With the use of advanced repair technologies they can become water sources eliminating new well drilling. The technology of physical and chemical decolmatation of filters and near-filter zones of artesian wells used for drinking and domestic water supply has been developed together with the technical means of its implementation. The developed process solutions and technical means tested on industrial scale provide for increasing the well debit (even restoring the initial debit set after drilling); in addition the financial and labor costs as well as the time consumption for repair works are much lower than for boring a new well. The technology of wave hydrodynamic drag is efficiently combined with the chemical stimulation methods (acidizing) and ensures the synergistic effect. The technology and equipment do not cause any destruction of the well filters, cement sheath or casing column integrity. The findings have been tested in the process of repairing dozens of water wells used for drinking purposes; the actual debit increase was 30–1150%.

Key words

ground water , water well , yield , bottom-hole formation zone , cavitation and chemical decolmatation , technical condition monitoring , stimulation of production