Study On Effect Of Drilling Fluids Components On Rock Drillability

It is a common phenomenon that different fluids are not consistent at the same external conditions,and the discussion of the causes is also a long time.In this paper,the effects of water-based drilling fluid components(surfactants,CMC,PHPA,bentonite)on rock drillability were investigated by micro-drilling method.The surfactants were studied using hard and brittle mud shales,and the remaining components were studied using natural marble.In this paper,a series of experimental methods for studying the interaction between drilling fluid and rock are designed based on the interaction between fluid and rock.The effect of five kinds of surfactants on the drilling speed of hard and brittle mud shale was studied.It was found that the surfactant could improve the ROP.In this paper,it is found that the surfactant with low concentration has a certain effect on the ROP,and the high concentration of surfactants can inhibit the ROP.The effect of the surfactant on the ROP was studied with mechanical and chemical properties as the starting point.It is believed that the low concentration of surfactant can promote the drilling ROP,mainly because the surfactant can promote the contact of the aqueous solution with the rock.The inhibitory effect of high concentration surfactants on ROP is mainly due to the high concentration in hard and brittle shales which has high abrasion and hardness.The lubricating performance of surfactants is very good,which reduces the grinding efficiency and produces a similar "slippery" phenomenon.In this paper,a method of non-stop alternation of fluid drilling is designed to eliminate the influence of thermodynamic factors on the penetration rate,which is created by the inconsistency between solution properties and friction coefficient.The effect of PHPA ?CMC and bentonite on the ROP of natural marble were analyzed.The conclusion was consistent with the previous study.The key factors influence ROP are viscosity and solid content.