The Study Of Surface-droved Progressive Cavity Pump Working Condition Diagnosis Technology

The progressive cavity pump is a kind of rotary displacement pump. As a new kind of artificial lifting way, it has many advantages. The structure is simple; the flow is well-distributed; the disturbance is small; the carry capacity is strong. It has so many advantages that it is well used in lifting the crude oil with high sand content, high air content or high viscosity. In recent years, the progressive cavity pumps play important roles in the oilfield exploitation. With the apply scale expanding, there are more faults happen. There are several fault types: sucker rod broken,oil leaked from pipes,paraffin blockage and some other faults. The working site requests for a higher working condition diagnosis.This thesis introduces the basic working principles and the component parts of the surface-droved progressive cavity pump oil production system. It also analyses the construction and the principle of the surface-droved PCP working condition diagnosis system. The paper makes the rod string force analysis. It also gives the calculation models and the vibration models. It summarizes the fault types and the parameter changes in different fault situations. In the end, it uses the fuzzy comprehensive diagnosis theory to build the judgement matrix for the field data analysis and makes a vibration analysis for the 21 screw pump wells.