METHOD OF DIAGNOSING SUCKER-ROD PUMP PLANTS WITH KNOWN EQUILIBRIUM STATE Russian patent published in 2002 - IPC

FIELD: oil producing industry; diagnosing of damages of sucker-rod pump plants. SUBSTANCE: according to proposed method plant power output is measured through discrete time intervals and diagnostic wattmeter diagram is found and smoothed, then power output variation rate is measured through the same discrete time intervals and phase curve of wattmeter diagram is plotted. Then, moduli of maximum and minimum values of power and power variation rate are determined and values of diagnostic coefficients K₁,K₂ and their ratio K₁₂ are calculated: where P_max is modulus of maximum power output of plant; P_min is modulus of minimum power output of plant; is modulus of maximum value of power output variation rate of plants; is modulus of minimum value of power output variation rate of plant. Depending on equilibrium of plant, ratio of diagnostic coefficients K₁₂ is compared with limited values found experimentally and if the following conditions are met, operation of pump plant is considered normal: for balance plants K_lim.1≤K₁₂≤K_lim.2; for non-balanced plants K_lim.3≤K₁₂ where . EFFECT: improved accuracy of diagnosing condition of sucker-rod pump plants by determining accurate number of readings at operation of pumping unit owing to use of information of equilibrium of plant, and analysis of spread of maximum and minimum values of power output and rate of its change. 1 tbl, 3 dwg