Abstract: The present disclosure relates to the technical field of wastewater treatment in oil and gas field operations, in particular to a method for synergistic degradation treatment of polysaccharide-containing polymer wastewater by controllable —OH radical. In this method, a ferrous ion solution, an alkaline solution, and an oxidant solution are mixed and heated to generate —OH radicals, —O radicals and polymeric iron ions, etc., which then is mixed with polysaccharide-containing polymer wastewater. The generated highly oxidative —OH radicals and —O radicals react with polysaccharide polymers so that they are degraded. The generated polymeric iron ions form flocs that purify the suspended solids in the wastewater. The purified polysaccharide-containing polymer wastewater can be re-injected or reused as an oilfield working fluid. In the present disclosure, the polysaccharide-containing polymer wastewater can be treated in a quick and efficient manner, and the treated wastewater can be recycled.

Abstract: An integrated boron removal and flocculation process for treating fracturing wastewater is disclosed. The process comprises: adjusting the pH of the fracturing flowback liquid to be treated to become alkaline and adding thereto an oxidant to carry out a reaction for a certain time period, so that the state of the boron present in the liquid is changed; and then adding a barium salt to the resulting reaction mixture to carry out a further reaction between the barium salt and the boron in the changed state to produce a precipitate. The stability of the flowback liquid is deteriorated by the addition of the oxidant. Suspended solids in the flowback liquid can be removed through adsorption, wrapping, and then settling by the action of the precipitate (a barium salt). The process integrates boron removal and flocculation and enables a boron removal rate of 80% or greater. The contents of the suspended solids and oil present in the fracturing flowback liquid after filtration each can be lowered to less than 5.

Abstract: The present disclosure relates to the technical field of wastewater treatment in oil and gas field operations, in particular to a method for synergistic degradation treatment of polysaccharide-containing polymer wastewater by controllable —OH radical. In this method, a ferrous ion solution, an alkaline solution, and an oxidant solution are mixed and heated to generate —OH radicals, —O radicals and polymeric iron ions, etc., which then is mixed with polysaccharide-containing polymer wastewater. The generated highly oxidative —OH radicals and —O radicals react with polysaccharide polymers so that they are degraded. The generated polymeric iron ions form flocs that purify the suspended solids in the wastewater. The purified polysaccharide-containing polymer wastewater can be re-injected or reused as an oilfield working fluid. In the present disclosure, the polysaccharide-containing polymer wastewater can be treated in a quick and efficient manner, and the treated wastewater can be recycled.

Abstract: The present invention discloses a remediation simulator of deep petroleum contaminated soil and application. The remediation simulator comprises a contaminated layer box. A to-be-remedied soil sample is added to a remediation box of the contaminated layer box; uncontaminated soil is added to cylindrical tubes to provide the pressure for the contaminated soil below; feed tubes are used for feeding liquid for remedying the soil; an air compressor conveys air to the soil and pushes the liquid to diffuse. The remediation simulator of the present invention has a simple structure and simple operations, can really and effectively simulate the deep contaminated soil environment, and also evaluates and screens a method for remedying the deep petroleum contaminated soil.