Study On Oil-based Drilling Fluid Reuse Technology In Tuo-Sheng-Yong Area

Oil-based drilling fluid system has been widely used in shale gas exploitation,oil and gas reservoir protection,exploition of oil and gas abroad and so on.Its application amount has gradually increased,followed by a series of problems.In the process of use,affected by technical limitations and improper operation methods,the overall reuse rate of oil-based drilling fluid after use is low,which leads to an increasing amount of abandoned oil-based drilling fluid.Oil-based drilling fluids are different from water-based drilling fluids,thus,in addition to the high cost of production and maintenance,it will also bring great environmental pollution problems.In this paper,we investigate and analysis used oil-base drilling fluid,summarize the reason of performance deterioration,and explore solutions.We aim to prolong the service life of oil-base drilling fluid,improve the repeating utilization factor,in order to provide the corresponding technical methods for promoting circulation of oil-based drilling fluid.A large amount of inferior solid phase is contained in the abandoned oil-base drilling fluid,but at present the separation level of solid control equipment is limited,resulting in the loss of use value of a large number of oil-base drilling fluid due to the continuous accumulation of dispersed particles,which cannot be reused.In this paper,a new type of flow regulator with activated carbon fiber as the main material is developed,which has a good flocculation effect on fine dispersed particles in the waste drilling fluid.By optimizing the waste oil-based drilling fluid recovered on site,the optimal composition was determined,and the actual adjustment effect was verified by on-site construction.According to the use of the flow regulator,a set of suitable oil-based drilling fluid performance control process is developed,which is convenient for field use and recovery.Our results show that for the submicron scale fine dispersed particles in waste oil-based drilling fluid,the flow type regulator showed a good flocculation effect.By increasing the particle size,centrifuge and other conventional solid equipment could clear it up more thouroughly,greatly reducing the solid content of waste oil-based drilling fluid.At the same time,it also adjust the rheology of drilling fluid.The regulator also showed good regulating effect in the application of yong123-ping3 well and lin25-ping6 well,achieved economic benefits,providing strong support for the subsequent oil-based drilling fluid reuse technology.