Other processing technologies
3.1 Demulsification: demulsification methods are mainly chemical demulsification, membrane demulsification, electric field demulsification, shear demulsification, heating demulsification, centrifugal demulsification, etc. Now more chemical demulsification is used, that is, adding demulsifier to emulsified oily drilling wastewater, through chemical action, supplemented by other separation methods, to achieve the purpose of emulsion de-stability, demulsification and oil-water separation. The chemical demulsification methods adopted at home and abroad mainly include salting-out method, acid-base method, condensation method and mixing method, but although these methods make the treatment effect remarkable, but because of the addition of chemical additives, the cost is increased, and the new impact on the environment is also brought.
According to the characteristics of waste drilling fluid as water-based and oil-based mixture, an efficient and economical treatment process was adopted. The results show that the treatment technology can effectively separate the three phases of oil, mud and water in the waste drilling fluid, reduce the amount of sludge, improve the content of pollutants in the effluent, and basically meet the national solid waste discharge standard after treatment, which basically solves the problem of disposal and discharge of waste drilling fluid in oil fields.
3.2 Mechanical Dehydration: This method is to separate the solid-liquid two phases from the waste drilling fluid by means of enhanced measures such as chemical flocculant deposition and mechanical separation. However, because of the different characteristics of drilling fluid produced by each oil field, a single flocculant can not make the drilling fluid of various properties carry out effective solid-liquid separation, and different flocculants should be used for different waste drilling fluids.
3.3 MTC (Mud To Cement) technology: the conversion of waste drilling fluid into cement slurry technology, referred to as MTC technology, which mixes waste drilling fluid with slag and uses activator to activate the solidified components in slag. With other additives to obtain various uses of cementing fluid. This technique has been studied extensively at home and abroad, and has been widely used. There are many advantages to cementing with it: low turbulent displacement, good compatibility with mud, short thickening transition time and static gel strength transition time.
With the continuous development of oil fields, drilling waste treatment has higher requirements, China’s drilling waste treatment work can not be compared with developed countries, because of its late start, research and application is still in a relatively basic stage, the control and prevention of drilling waste liquid is still not in place, and there is still a big gap with the world’s advanced level, so we should increase the research on drilling waste liquid treatment and application, and strive to prevent drilling waste liquid as the focus of drilling pollution control.