Shale gas development often suffers from wellbore instability due to microfractures in the formation,posing serious challenges to drilling safety and efficiency.This study presents a functionalized graphene oxide(GO-P...Shale gas development often suffers from wellbore instability due to microfractures in the formation,posing serious challenges to drilling safety and efficiency.This study presents a functionalized graphene oxide(GO-PAA)nanomaterial,prepared by grafting hydrophilic polyacrylic acid(PAA)chains onto GO surfaces to enhance dispersion stability under high salinity,elevated temperature,and wide pH conditions.The results indicate that GO-PAA effectively resists charge-shielding effects under conditions of high salinity,elevated temperature,and a wide pH range,significantly reducing the risk of particle aggregation.Even at high salt concentrations,the zeta potential remains below-32.8 mV,demonstrating good colloidal stability.Plugging performance was evaluated using simulated core experiments.GO-PAA fo rmed a"band-aid"like barrier on shale microfracture surfaces,reducing permeability by up to57.53%,nearly twice that of conventional spherical nano particles.Scanning electron microscope(SEM)and elemental analysis confirmed the formation of a dense and uniform plugging layer.The synergistic interaction between GO's 2D lamellar structure and the flexible polymer chains facilitated effective surface adhesion and coverage.This adsorption-adhesion plugging mechanism represents a shift from traditional bridging theories,enabling reduced material usage and improved efficiency.The findings provide theo retical and practical support for designing high-perfo rmance nanoplugging agents in waterbased drilling fluids,contributing to safer and more sustainable shale gas development.展开更多
An electroless deposition（ELD） method is introduced to fabricate a metal nanoplug for its advantages of simplicity,low cost and auto-selectivity.It was demonstrated that nanoplugs of less than 50 nm in diameter can ...An electroless deposition（ELD） method is introduced to fabricate a metal nanoplug for its advantages of simplicity,low cost and auto-selectivity.It was demonstrated that nanoplugs of less than 50 nm in diameter can be fabricated by ELD nickel on various substrates,such as silicon,tungsten and titanium nitride.The main composition of the ELD nanoplug was characterized as nickel by an energy dispersive X-ray microanalyzer.A functional vertical phase-change random access memory（PCRAM） device with a heater diameter of around 9μm was fabricated by using the ELD method.TheⅠ-Ⅴcharacteristics demonstrated that the threshold current is only 90.8μA.This showed that the ELD process can satisfy the demands of PCRAM device application,as well as device performance improvement.The ELD process provides a promising method for the simple and low-cost fabrication of metal nanoplugs.展开更多
基金supported by the Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation[PLN202413]the National Natural Science Foundation of China(52274008)+1 种基金the National Key R&D Projects(2019YFA0708303)the Science and Technology Cooperation Project of the CNPCSWPU Innovation Alliance(2020CX040102,2020CX040201)。
文摘Shale gas development often suffers from wellbore instability due to microfractures in the formation,posing serious challenges to drilling safety and efficiency.This study presents a functionalized graphene oxide(GO-PAA)nanomaterial,prepared by grafting hydrophilic polyacrylic acid(PAA)chains onto GO surfaces to enhance dispersion stability under high salinity,elevated temperature,and wide pH conditions.The results indicate that GO-PAA effectively resists charge-shielding effects under conditions of high salinity,elevated temperature,and a wide pH range,significantly reducing the risk of particle aggregation.Even at high salt concentrations,the zeta potential remains below-32.8 mV,demonstrating good colloidal stability.Plugging performance was evaluated using simulated core experiments.GO-PAA fo rmed a"band-aid"like barrier on shale microfracture surfaces,reducing permeability by up to57.53%,nearly twice that of conventional spherical nano particles.Scanning electron microscope(SEM)and elemental analysis confirmed the formation of a dense and uniform plugging layer.The synergistic interaction between GO's 2D lamellar structure and the flexible polymer chains facilitated effective surface adhesion and coverage.This adsorption-adhesion plugging mechanism represents a shift from traditional bridging theories,enabling reduced material usage and improved efficiency.The findings provide theo retical and practical support for designing high-perfo rmance nanoplugging agents in waterbased drilling fluids,contributing to safer and more sustainable shale gas development.
基金Project supported by the National High-Tech Research and Development Program of China(No2008AA031402)the National Natural Science Foundation of China(Nos60606024,61076077)
文摘An electroless deposition（ELD） method is introduced to fabricate a metal nanoplug for its advantages of simplicity,low cost and auto-selectivity.It was demonstrated that nanoplugs of less than 50 nm in diameter can be fabricated by ELD nickel on various substrates,such as silicon,tungsten and titanium nitride.The main composition of the ELD nanoplug was characterized as nickel by an energy dispersive X-ray microanalyzer.A functional vertical phase-change random access memory（PCRAM） device with a heater diameter of around 9μm was fabricated by using the ELD method.TheⅠ-Ⅴcharacteristics demonstrated that the threshold current is only 90.8μA.This showed that the ELD process can satisfy the demands of PCRAM device application,as well as device performance improvement.The ELD process provides a promising method for the simple and low-cost fabrication of metal nanoplugs.
