FIELD: oil and gas industry.
SUBSTANCE: method of diagnosing of pump unit is offered which contains the following stages: the land measurements are performed which give surface load and the position of surface of the rod string on the surface; the axial and transversal movements of the rod string are characterized by two related fourth order nonlinear differential equations comprising the axial movement equation and the transversal movement equation; the initial axial movement of the rod string is calculates, assuming the absence of transversal movement and by solving the axial movement equation; the initial axial force is calculated, using initial axial movement and assuming absence of transversal movement; the initial transversal movement of the rod string is calculated, using the initial axial force and the initial axial movement; the axial force and the friction force are calculated, using initial axial and transversal movements; the axial movement in the borehole pump is calculated, by solving the equation of axial movement with reference to axial force and friction force; the load on the borehole pump is calculated; also the borehole chart is plotted which represents the load connected with axial movement of the borehole pump. Also the controller for implementation of the described method is offered.
EFFECT: exact informative diagnostics for efficient control of pump system.
10 cl, 8 dwg
Authors
Dates
2015-11-10—Published
2012-10-29—Filed