The invention discloses a method for centralized treatment and comprehensive utilization of
foam drainage during gas production in oil-gas fields. The method comprises the steps: firstly, collecting the drainage into a
grease trap for treatment so as to obtain
solid sludge and preliminarily-treated drainage; and conveying the treated drainage to a coagulation air-floatation
degreasing device, andperforming
aeration and
degreasing treatment so as to obtain
solid sludge and secondarily-treated drainage; conveying the obtained drainage to an iron-carbon micro-
electrolysis device, performing a micro-
electrolysis reaction so as to obtain
sludge after the reaction treatment is conducted, conveying the obtained drainage to a
softening reaction
sedimentation tank, performing
softening hardness removal treatment, performing settlement to obtain sludge, conveying the obtained drainage to a
water softening pool for
softening treatment so as to obtain qualified
softened water, and conveying the obtained qualified
softened water into a water purification
pool, wherein the obtained qualified water can be directly applied to re-injection or multi-effect
evaporation treatment and is subjected toup-to-standard
discharge; and performing centralized treatment and
recovery on the sludge obtained in the steps.
Grease and salts in the
foam drainage wastewater during gas production can be recoveredfully, the
foam drainage obtained after the centralized treatment is conducted can be introduced into an
evaporation system for
evaporation treatment, and the obtained drainage is subjected to up-to-standard
discharge and can be utilized comprehensively as oilfield re-injection water, so that
resource utilization is achieved.