Novel Environmentally Friendly Lubricants for Drilling Fluids Applied in Shale Formation

Abstract

One of the biggest difficulties with water-based drilling fluids for shale horizontal wells is its relatively high friction, especially for long horizontal wells. Improving the lubricating ability of drilling fluids is very important for expanding the extension range of horizontal wells in unconventional oil and gas wells. In this work, three kinds of lubricants, graphene oxide (GO), choline chloride/glycerol deep eutectic solvent (Gly-DES), and GO/Gly-DES, were synthesized to investigate their ability to improve the lubricity of water-based drilling fluids. These synthesized lubricants were all environmentally friendly. The tribological test and the filter cake adhesion coefficient test were used to compare the lubricity of these fluids. On the other hand, the traditional commercial lubricant solid graphite (HY-202) was taken as the reference sample. The results indicated that GO and Gly-DES can exert a more obvious lubricating effect at much lower concentrations compared to the reference sample. GO (0.25 wt %) can reduce the adhesion coefficient of filter cake by 93.33% and the friction coefficient of drilling fluid by 48.47%. The complex of GO and Gly-DES can further increase the reduction rate of adhesion coefficient and friction coefficient. Whether it was in reducing the adhesion coefficient of the filter cake or the friction coefficient of the drilling fluids, the combined lubrication effect of GO and Gly-DES was significantly better than using GO or Gly-DES alone. GO and Gly-DES decreased the coefficient of friction due to their good ability in producing a strong protective film on the contacting surfaces of the metal and filter cake. GO and Gly-DES can slightly reduce the filtration volume of drilling fluids and are suitable for shale water-based drilling fluids.

Advanced developments in environmentally friendly lubricants for water-based drilling fluid: a review

“…In addition, GO and Gly-DES do not increase the ltration volume of drilling uids, whether used alone or in combination. 77 Wang et al used the cationic surfactant CTAC to modify the surface of natural ake graphite to improve the dispersibility of graphite in water-based drilling uids. The authors evaluated the lubricating properties of modied graphite by the viscosity coefficient (VC).…”

“…In addition, GO and Gly-DES do not increase the filtration volume of drilling fluids, whether used alone or in combination. 77 …”

“…The complete elimination of uorescence is one of the biggest challenges of water-based drilling uid lubricants. From the perspective of molecular design, it is the most effective means to eliminate the main sources of uorescence, that is, Graphene enhanced lubricant has little effect on the rheological parameters of drilling uid Sulfonated modied graphene 76 Not mentioned Graphene oxide (GO) 72,77 GO has no obvious effect on the rheological properties of drilling uid CTAC modied graphene 78 CTAC modied graphene has no obvious effect on the rheological properties of drilling uids The lubricant molecules with a layered structure are deposited on the friction surface, so that the direct contact between the friction surfaces is converted into the relative slippage of the lubricant molecular layer, thereby reducing the friction coefficient double bonds, conjugated double bonds, and condensed ring structures with P electrons in the molecular structure. As for biodiesel-based lubricants, their serious impact on drilling uid performance is an important factor restricting their application and development.…”

Application of Nanofluids for Machining Processes: A Comprehensive Review

“…In the drilling machining operations, graphene nanosheets with an aqueous solution [ 40 ], multiwalled carbon nanotubes with an aqueous solution [ 41 ], graphene oxide/phosphorylated graphene oxide with an aqueous solution [ 43 ], iron with water [ 60 ], multiwalled carbon nanotubes modified with OH with an aqueous solution, graphene-oxide-based novel lubricants (GO, Gly-DES, GO/Gly-DES) with an aqueous solution [ 54 ], graphene oxide nanosheets with aqueous solutions [ 57 ], polyacrylamide with an aqueous solution [ 57 ], carbon nanofibers with water [ 58 ], oxidized multi-walled carbon nanotubes wrapped by polyethylene glycol with water-based cutting fluid [ 59 ], and iron with Jatropha oil, are all of the nanoparticles with certain base fluids that are combined to form nanofluid. These nanofluids are later used in the drilling machining process, which helps in the reduction in the cutting temperature by providing an improvement in the surface in order to reduce thermal losses.…”

A novel choline chloride/graphene composite as a shale inhibitor for drilling fluid and the interaction mechanism

“… 30 In view of the lubricating properties of graphene materials, lubricants based on graphene materials were used in water-based drilling fluids. 31 They relied on adsorption to form a layer of film on the surface of the filter cake, which reduced the wear of drilling tools and slightly reduced the filtration of drilling fluid. Recently, there have been studies on graphene materials for shale inhibitors.…”