Well flushing refers to the process of injecting the washing medium through the wellbore or drill pipe through the pumping equipment during the workover operation due to engineering needs, carrying the substancesin the wellbore to the surface, thereby changing the properties of the medium in the wellbore to meet the operational requirements.Well washing can increase the oil-water flow channel between oil wells and reservoirs, thereby increasing oilfield production.

In general, well washing waste water enters the joint station for treatment through recovery pipelines and is reinjected into the formation. However, water injection wells in single wells or remote small oil fields are more dispersed, and generally no well washing wastewater recovery pipelines are installed. Usually, the wastewater from well washing is directly discharged into the wastewater pit near the well site for natural evaporation and infiltration, or collected by tank trucks for centralized treatment. The former has an impact on soil and vegetation, damaging the surrounding environment, while the latter has high treatment costs.

The use of well Dewax rig and Well Flush rig can avoid huge pipeline investment, reduce the impact on the main process of sewage treatment stations, achieve non discharge of sewage during the well washing process, improve sewage treatment capacity, save water resources, reduce oil well production costs, protect the ecological environment, and improve crude oil recovery rate.

For this,Sanjack designed the Well Flushing and Dewaxing truck as the hot oil unit for workover and drilling service.Our Well Flushing and Dewaxing truck has the functions of pressurized circulating well washing and backwashing, suitable for purifying and treating the returned liquid from well washing, removing suspended solids, oils, and other pollutants, and re injecting the well washing liquid into the well for closed circulation well washing.

According to the daily production level, production layer series, and water content of oil wells, they are divided into three categories and different well washing schemes are adopted for different oil wells. For oil wells with low formation pressure, daily oil production of over 4 tons, water content of less than 70%, and wax content of over 8%, the method of first washing the well with hot sewage and then washing the well with hot oil is adopted. For oil wells that have been cleaned with wax agents for a long time, regular and thorough oil cleaning should be carried out to maintain the relative stability of oil well production. For low production oil wells with low production, low water content, high wax content, and deep dynamic liquid surface, hot wastewater is first used to wash the well, and then medicine is added to the casing for wax removal, which not only prolongs the hot washing cycle but also increases crude oil production.

The hot oil unit is also called as Flushing and Dewax unit, which integrates multiple functions such as high-pressure well flushing, hot well flushing, steam wax removal, and pressure testing. Its advantages include stable medium flow, high thermal efficiency, high equipment utilization rate, long service life, safe and reliable burner ignition, and convenient maintenance and repair.