METHOD OF FLUORESCENT CONTROL OF PLASMA STRUCTURE AND TREATED SURFACE IN TECHNIQUE OF DOWNHOLE EQUIPMENT ANTICORROSION PROTECTION

Abstract

Relevance. Reliability and integrity of oil production equipment, its operation time are provided by a set of measures to combat corrosion, in particular, to use gas-plasma sputtering of protective coatings on designed or restored technology parts. In these technologies, the heterogeneous chemiluminescence phenomenon can serve as an effective method for monitoring plasma composition state and the sputtered surface quality. Heterogeneous chemiluminescence reactions has selectivity and high sensitivity to surface type and excitation gas grade. The use of optical methods to study and control in non-equilibrium gas–solid systems opens up new analytical possibilities in surface physics, chemistry, plasma chemistry, semiconductor and phosphor technology, and in solving environmental problems. Study of adsorption, desorption, dissociation, diffusion, gas particles recombination, defect formation and crystal lattice growth using heterogeneous chemiluminescence phenomenon is an urgent task in condensed matter physics, as the heterogeneous chemiluminescence phenomenon realizes the possibility of selective rapid analysis methods with simple hardware equipment at detection limit of free atoms, radicals, impurities in gas phase and the surface layers composition condensed matter to 10–6% (mol). The main aim of the research is to study the processes in non-equilibrium systems gas–solid and to determine the interaction based on the registration of characteristics of heterogeneous chemiluminescence; to develop the methods for determining time-dependent interaction parameters of gas-solid using heterogeneous chemiluminescence phenomenon, to monitor the parameters of gaseous medium and the state of condensed matter surface. Objects: atomic-molecular hydrogen beams, crystalline phosphorus ZnS–Mn2+, near-surface gas-solid interaction regions. Methods: methods based on heterogeneous chemiluminescence phenomenon in atomic hydrogen for determining adsorption rate and H atoms recombination, H2 molecules desorption rate, heat of hydrogen atoms desorption from ZnS–Mn2 +surface. Using the «dark» pause method, the recombination rate of adsorbed atoms was obtained by the Langmuir–Hinshelwood mechanism. Results. The authors have carried out the comparative study of ZnS–Mn2 +luminescence upon light (photoluminescence) and atomic hydrogen (heterogeneous chemiluminescence) excitation. Spectral-kinetic characteristics of luminescence were studied and mechanisms and parameters of interaction of hydrogen atoms with zinc sulfide surface (cross sections, frequency factors, activation energies) based on the kinetic characteristics of heterogeneous chemiluminescence were determined. It is shown that the ZnS-Mn2+ phosphor can serve as an express sensor reducing plasma component (hydrogen). Heterogeneous chemiluminescence phenomenon is an effective method to control the initial step of modification and composition of solids surface in beam-plasma treatment of materials.

Keywords

• oil and gas equipment
• corrosion
• protective coatings
• gas-plasma spraying
• photoluminescence
• heterogeneous chemiluminescence
• surface
• hydrogen atoms
• non-stationary processes
• interactions of hydrogen atoms with the surface