On-line temperature monitoring of plasma sprayed coating is presented, which is based on IR pyrometery combined to robot trajectories. Temperature fields of the substrate before spraying and the deposited coating when...On-line temperature monitoring of plasma sprayed coating is presented, which is based on IR pyrometery combined to robot trajectories. Temperature fields of the substrate before spraying and the deposited coating when the damage happens are taken to investigate the temperature fluctuation information. Experimental results demonstrate that coating damage always occurs in the temperature transition area of the substrate from the higher to the lower, as well as the higher temperature area. The temperature difference between the peak and the mean of the relevant regions is beyond 30 - 50℃ or even higher. This case provides the omen of coating damage and the focusing scopes for the process control of coating temperature in plasma spraying展开更多
Pencil hardness testing,electrochemical impedance spectroscopy,scanning electron microscopy,and scanning Kelvin probe microscopy were used to study the local corrosion characteristics of a graphene-oxide-modified inne...Pencil hardness testing,electrochemical impedance spectroscopy,scanning electron microscopy,and scanning Kelvin probe microscopy were used to study the local corrosion characteristics of a graphene-oxide-modified inner coating.The effect of chloride concentration on the corrosion of the damaged inner coating was studied.The effects of chloride ions on damaged internal coatings and graphene-oxide-modified internal coatings were investigated.It was proposed to add graphene oxide into the epoxy coating to effectively inhibit the metal corrosion at the breakage.Because of the existence of graphene oxide(GO),the modified coating had a better physical property and had the effective infiltration of H2O and Cl^- into the coating.The results showed that graphene oxide coatings can give X80 steel better corrosion resistance in sodium chloride solution.展开更多
Single-pulse and multi-pulse damage behaviors of ＂standard＂ （with A/4 stack structure） and ＂modified＂ （with reduced standing-wave field） HfO2/SiO2 mirror coatings are investigated using a commercial 50-fs, 800...Single-pulse and multi-pulse damage behaviors of ＂standard＂ （with A/4 stack structure） and ＂modified＂ （with reduced standing-wave field） HfO2/SiO2 mirror coatings are investigated using a commercial 50-fs, 800-nm Ti：sapphire laser system. Precise morphologies of damaged sites display strikingly different features when the samples are subjected to various number of incident pulses, which are explained reasonably by the standing-wave field distribution within the coatings. Meanwhile, the single-pulse laser-induced damage threshold of the ＂standard＂ mirror is improved by about 14% while suppressing the normalized electric field intensity at the outmost interface of the HfO2 and SiO2 layers by 37%. To discuss the damage mechanism, a theoretical model based on photoionization, avalanche ionization, and decays of electrons is adopted to simulate the evolution curves of the conduction-band electron densitv during r^ulse dHratian.展开更多
In order to find an economic and effective water control method for horizontal wells in deep sea bottom-water gas reservoirs,we prepared modified coated gravel.Based on this,wear resistance,temperature resistance and ...In order to find an economic and effective water control method for horizontal wells in deep sea bottom-water gas reservoirs,we prepared modified coated gravel.Based on this,wear resistance,temperature resistance and water plugging capacity(WPC)tests were carried out on the coated gravel.Then,experiments were carried out using the 3D simulation device for the development of large-scale bottom-water gas reservoirs to compare the development effects of horizontal wells packed with conventional gravel and coated gravel in deepsea bottom-water gas reservoirs.And the following research results were obtained.First,the upper limit of temperature resistance of the gravel coating is 240℃ and the gravel packing speed can reach 4.48 m/s,which is 8 times the average flow velocity of gravel packing in actual open hole sections.Second,as the permeability of the coated gravel packing layer increases,its WPC gets weak.When the permeability is lower than 1500 mD and the displacement pressure difference is lower than 0.6 MPa,the WPC of the coated gravel packing layer is between 0.17 and 0.68.Third,the coated gravel layer functions as gas permeability and water plugging,so the horizontal well technology with coated gravel packing can reduce the flow capacity of water phase breaking into the dominant flow passage,so as to delay the rise of water production of gas well and prolong the gas production time.In this way,the gas recovery factor of bottom-water gas reservoir can be increased effectively.In conclusion,this technology has the function of spontaneous selective water plugging,i.e.,“water plugging in case of water and gas permeability in case of gas”,and its technical and economic advantages are remarkable,which can provide a new idea for the water-control development of deepsea bottom-water gas reservoirs.展开更多
基金The work is supported by the National Natural Science Foundation of China （No. 51005085）.
文摘On-line temperature monitoring of plasma sprayed coating is presented, which is based on IR pyrometery combined to robot trajectories. Temperature fields of the substrate before spraying and the deposited coating when the damage happens are taken to investigate the temperature fluctuation information. Experimental results demonstrate that coating damage always occurs in the temperature transition area of the substrate from the higher to the lower, as well as the higher temperature area. The temperature difference between the peak and the mean of the relevant regions is beyond 30 - 50℃ or even higher. This case provides the omen of coating damage and the focusing scopes for the process control of coating temperature in plasma spraying
基金Project(51674212)supported by the National Natural Science Foundation of China。
文摘Pencil hardness testing,electrochemical impedance spectroscopy,scanning electron microscopy,and scanning Kelvin probe microscopy were used to study the local corrosion characteristics of a graphene-oxide-modified inner coating.The effect of chloride concentration on the corrosion of the damaged inner coating was studied.The effects of chloride ions on damaged internal coatings and graphene-oxide-modified internal coatings were investigated.It was proposed to add graphene oxide into the epoxy coating to effectively inhibit the metal corrosion at the breakage.Because of the existence of graphene oxide(GO),the modified coating had a better physical property and had the effective infiltration of H2O and Cl^- into the coating.The results showed that graphene oxide coatings can give X80 steel better corrosion resistance in sodium chloride solution.
文摘Single-pulse and multi-pulse damage behaviors of ＂standard＂ （with A/4 stack structure） and ＂modified＂ （with reduced standing-wave field） HfO2/SiO2 mirror coatings are investigated using a commercial 50-fs, 800-nm Ti：sapphire laser system. Precise morphologies of damaged sites display strikingly different features when the samples are subjected to various number of incident pulses, which are explained reasonably by the standing-wave field distribution within the coatings. Meanwhile, the single-pulse laser-induced damage threshold of the ＂standard＂ mirror is improved by about 14% while suppressing the normalized electric field intensity at the outmost interface of the HfO2 and SiO2 layers by 37%. To discuss the damage mechanism, a theoretical model based on photoionization, avalanche ionization, and decays of electrons is adopted to simulate the evolution curves of the conduction-band electron densitv during r^ulse dHratian.
基金Project supported by Scientific and Technological Project of CNOOC(China)Limited“Study on Key Drilling and Completion Technologies for Deepwater Development Well”(No.:CNOOC-KJ 135 ZDXM 05 LTD 01 SHENHAI 2016).
文摘In order to find an economic and effective water control method for horizontal wells in deep sea bottom-water gas reservoirs,we prepared modified coated gravel.Based on this,wear resistance,temperature resistance and water plugging capacity(WPC)tests were carried out on the coated gravel.Then,experiments were carried out using the 3D simulation device for the development of large-scale bottom-water gas reservoirs to compare the development effects of horizontal wells packed with conventional gravel and coated gravel in deepsea bottom-water gas reservoirs.And the following research results were obtained.First,the upper limit of temperature resistance of the gravel coating is 240℃ and the gravel packing speed can reach 4.48 m/s,which is 8 times the average flow velocity of gravel packing in actual open hole sections.Second,as the permeability of the coated gravel packing layer increases,its WPC gets weak.When the permeability is lower than 1500 mD and the displacement pressure difference is lower than 0.6 MPa,the WPC of the coated gravel packing layer is between 0.17 and 0.68.Third,the coated gravel layer functions as gas permeability and water plugging,so the horizontal well technology with coated gravel packing can reduce the flow capacity of water phase breaking into the dominant flow passage,so as to delay the rise of water production of gas well and prolong the gas production time.In this way,the gas recovery factor of bottom-water gas reservoir can be increased effectively.In conclusion,this technology has the function of spontaneous selective water plugging,i.e.,“water plugging in case of water and gas permeability in case of gas”,and its technical and economic advantages are remarkable,which can provide a new idea for the water-control development of deepsea bottom-water gas reservoirs.
