Working condition diagnosis of ESP well based on wellhead pressure-out analysis

Current card of electric submersible pump well fails to discriminate effectively the leakage of electric submersible pump (ESP) or pipe string, the decline of pump lifting capacity and low pump efficiency. In order to solve this problem, ESP diagnosis process and method based on wellhead pressure-out analysis (shut in the wellhead without stopping the pump) was put forward. Based on the ESP characteristic curve and IPR curve (inflow performance relationship), the theoretical pressure-out curve model was established by analyzing the flowing state of gas and liquid in the borehole before pressure out. Then, the way to extract curve characteristic parameters was determined. And finally, the failure type was discriminated by comparing the characteristic parameters of theoretical pressure-out curve with the measured values. Field application indicates that this method can be used as the effective way to diagnose the working conditions of ESP wells comprehensively.