Investigation of the effect of formation water disposal on ground water in oil fields of Assam, India

One of the major waste products of oil industry is formation water which comes with crude oil from underground and this is considered as pollutant because of the presence of several undesirable elements exceeding the permissible limits. The conventional oil field practice is to dispose the formation water by injecting underground. Such underground injection is practiced in many oil fields across the globe. The ground water pollution threat by injected formation water has been a subject matter of investigation in some oil producing regions. The oil fields in Assam (India), some of which have been operating for about 50 years, also resort to similar disposal practice through some designated wells. The present study concerning underground disposal of formation water in 15 disposal wells of 3 oil fields in Assam analysed water samples collected during three consecutive years and could not detect migration of pollutant formation water to nearby ground water.