Disposal of Mercury-sulfide and Residual Ash by Deep Well Injection

摘要

INA Oil Company, Plc. Zagreb is a Croatian company engaged in the exploration and production of oil andrngas, refining and distribution of petroleum products. An enormous quantity of hazardous waste is generated inrnoil and gas production and thus has to be disposed in a permanent and safe manner. In recent years, INA hasrnbeen disposing waste by injection into exploration dry wells and production depleted wells.rnA specific waste disposal problem has arisen in the process of gas and condensates in Molve, Kalinovac, StarirnGradec and Gola fields. Namely, mercury-sulfide, sulfur slurry and heavy metals have been separated duringrnthe production of gas and condensate.rnMercury-sulfide has been separated in the process of active coal utilization. The disposal of active coalrnsaturated with mercury-sulfide is a very complex issue. So far, the methods of mercury-sulfide disposal havernnot been ecologically acceptable. However, on the basis of new experience and knowledge in that field, wasterndispersed in a bentonite suspension may be disposed in a permanent and safe manner into appropriaterngeological formations. In the same way, when combusting various types of industrial and municipal waste, thernproblem of residual ash disposal emerges. Such residual ash contains heavy metals which may be permanentlyrndisposed by using the above mentioned method. This paper deals with the experience of waste disposal byrndeep well injection in the Republic of Croatia.