Pumping control system and method based on dynamic level and casing pressure

Abstract

The invention discloses a pumping control system and method based on dynamic level and casing pressure. The system comprises a master control platform, an oil production detector, a pumping adjustingmechanism and an electromagnetic valve; the method comprises the steps of I, acquiring dynamic level of an oil well and casing pressure data; II, calculating a dynamic level deviation and change rateof the dynamic level deviation; III, judging whether a measured value of the dynamic level of the oil well meets 0.7 D0< / =Di< / =1.3 D0; IV, performing fuzzy processing on the dynamic level deviation and the change rate of the dynamic level deviation; V, determining power output fuzzy state and frequency output fuzzy state value for an inverter; VI, determining frequency fuzzy quantity of the frequency output of the inverter; VII, adjusting stroke frequency of a motor, and adjusting casing pressure of the oil well; VIII, correcting dynamic level data of the oil well and an initial set value of the casing pressure of the oil well. The pumping control system and method based on dynamic level and casing pressure have the advantages that measured depth of an oil well and set depth are used to comparatively adjust output frequency of an inverter, stroke frequency of a pumping unit is controlled, pressure changes are used to adjust opening and closing of the electromagnetic valve to adjust inner pressure of an annulus of the oil well, the dynamic level is stabilized, and the pumping unit is enabled to be in optimal pumping state.

Description

technical field [0001] The invention belongs to the technical field of oil pumping control, and in particular relates to an oil pumping control system and method based on a dynamic liquid level and casing pressure. Background technique [0002] The depth of dynamic liquid surface in oil well determines the bottom hole flow pressure and the submergence of pumping unit, and its depth change affects the fluid production and pumping efficiency of oil well. With the deepening of the dynamic liquid level, the pressure of the liquid column in the upper section of the pumping unit decreases, causing more gas to enter the pumping unit and reduce the pumping efficiency of the pumping unit. in a low-volume working state. In addition, in the process of oil field production, when the casing pressure increases, the casing pressure provides part of the energy for the liquid in the oil well, pushing the liquid into the pump barrel, thereby increasing the filling coefficient of the pumping ...

AI Technical Summary

Problems solved by technology

With the deepening of the dynamic liquid level, the pressure of the liquid column in the upper section of the pumping unit decreases, causing more gas to enter the pumping unit and reduce the pumping efficiency of the pumping unit. in a low-volume working state

In addition, in the process of oil field production, when the casing pressure increases, the casing pressure provides part of the energy for the liquid in the oil well, pushing the liquid into the pump barrel, thereby increasing the filling coefficient of the pumping unit. However, when the casing pressure increases to When the value is certain, if it continues to increase, gas will mainly flow in the oil pipe, and the gas will enter the pumping unit, causing the pumping unit to be not fully filled, which also reduces the pumping efficiency of the pumping unit, and when the gas is seriously affected , due to the compression and expansion of the gas in the pumping unit, the suction valve cannot be opened and the oil cannot be pumped out, and the "air lock" phenomenon occurs

The current pumping control system is usually a closed-loop control system based on the dynamic fluid level. This control system only considers the influence of a single factor of the dynamic fluid level, and does not consider the impact of the casing pressure change of oil wells with different fluid supply capabilities on oil production. It has great limitations, and because this kind of closed-loop control system often adopts linear control method for control, the control effect is poor, and the efficiency of the pumping unit cannot be kept at the highest state for a long time and stably

In addition, most of the current casing pressure control is manual control. Operators regularly go to the site to open the manual ball valve to discharge according to the casing pressure gauge data. This manual control method is complicated to operate and has high labor costs.

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