Optimization Of Treatment Process For Production Of Water Containing Alcohol In Chang Bei Gas Field

Changqing gas field is located in the middle of Ordos Basin,mainly including Jingbian,Yulin and Sulige gas field.Because of regional characteristics,Changqing gas field belongs to the "four low" gas fields,namely low production,low pressure,low permeability and low abundance.The equilibrium temperature of gas hydrate formation in Changqing gas field is 23 degrees,while the natural gas temperature at the wellhead is generally only 15~18 degrees centigrade.It is easy to hydrate.Therefore,it is necessary to inject alcohol to prevent hydrate formation.Most of the injected methanol is miscible with the effluent from the pipeline.After the gas station and the natural gas treatment plant are separated from the natural gas,the gas field containing methanol is produced,Due to the large amount of methanol injection(about 3%~50% of the produced water),it is necessary to recycle methanol and recycle it to reduce the cost of natural gas recovery.Methanol is a kind of moderately toxic substance,and the gas field containing alcohol produced water has many points,wide surface and complex composition,and must be properly treated from the environmental point of view.After treatment,the waste water after methanol is treated and returned to the bottom after the gas field reinjection index,so as to realize the zero discharge on the ground.One of the key problems in the treatment of water containing wastewater from gas field is to pre treat the wastewater to reduce the concentration of suspended solids in sewage and improve the pH value of sewage..Based on the analysis of the pretreatment process and the reasons for the blockage of the methanol recovery unit in the production process of the methanol containing water in Chang Bei gas field,we find that the pretreatment process and the selection of the additives have a significant impact on the treatment effect of the produced water containing alcohol.This paper focuses on the Changbei gas field and alcohol containing produced water quality analysis,pretreatment process and reagent addition as the core,in Changbei alcohol produced water treatment during the operation,the Changbei alcohol made the evaluation production adaptability of pretreatment process water and find solutions at the same time,through analysis and experiment the operation experience,select suitable demulsifier,coagulant dosage was determined at the same time.