An anti sand pump with an anti-buried standing valve
In order to solve the problem of sand stuck in the sucker rod pump, an anti-sand sucker rod pump is designed. The anti-sand sucker rod pump includes the conventional sucker rod pump and the swirl flow device. The sand particles can be separated from the oil in the swirl flow device, so the plunger of the sucker rod pump cannot be stuck.
The motion equation of the sand particles in oil is deduced. The sucker rod pump is one of the important pieces of equipment in oil production. However, the extracted fluid in many oil wells contains a number of solid particles (sands). So the conventional sucker rod pump has some problems in the sandy wells. For example, the sands suspended in the oil will cause the wear of the plunger of the sucker rod pump if the sands fall into the clearance between the plunger and the barrel. In the worst case, the pump even is stuck and becomes a failure.
Up to now, some anti-sand sucker rod pumps have been developed to prevent the pump from sand damage. However, these anti-sand sucker rod pumps cannot have a good effect. In recent years, swirl flow technology has been a research topic in the oil and gas industry. So a new type of sucker rod pump based on the swirl flow is designed in this paper. The principle of the new sucker rod pump is that the swirl flow device in the sucker rod pump can separate the sand from the oil because of the centrifugal force. So the sand cannot fall into the clearance between the plunger and the barrel of the pump.
The sucker rod pump is a common down-hole device driven by the pumping unit to pump the crude oil in the well to the surface, an important part of the artificial lifting system. The safety and reliability of pump operation and long inspection period are critical, which can greatly reduce the loss of operation time and increase oil production. However, the well fluid usually contains sand particles, which will often bury the standing valve, greatly reducing the profit of crude oil production in the end.
At present, the standing valve of the sand control pump used in the oil field, the standing valve is directly connected to the pump barrel, and the well fluid enters the pump barrel through the oil hole in the upper part of the standing valve. During the pumping process, the sand particles pass along the upper part of the sanding valve cage. The oil hole falls back into the standing valve, and the fixed valve is buried in sand, causing the oil pump to fail.
This patent introduces an anti sand pump with an anti-buried standing valve, which can prevent sand particles from entering the standing valve and directly into the tailpipe, thereby effectively preventing the standing valve from being buried in sand, especially suitable for heavy oil sand wells.
The structure of the oil pump is as follows:
The anti-buried standing valve of the sucker rod pump is composed of a lower joint of the pump barrel (1), an outer pipe joint (2), a standing valve cage(3), a valve ball(4), a valve seat(5), a joint of the sand trap barrel(6), a screen sleeve(7), a coupling(8), a tail pipe(9), and an anti-sand cap(10). The upper end of standing valve cage (3) has a tapered surface, and one or more tapered holes are radially opened on the side. The standing valve cage, valve ball, and valve seat are installed on the upper part of the sand trap barrel joint and suspended, and the lower end of the grit tube joint(6) is connected to the tail pipe(9) through the coupling(8). an anti-sand cap(10) is installed at the lower end of the tail pipe(9), and the anti-buried standing valve is connected to the lower end of the sucker rod pump through the lower joint of the pump barrel(1). During the upstroke of the pump, the pressure on the upper part of the standing valve is reduced.
Under the action of the well fluid pressure, the well fluid enters from the side hole of joint of the sand trap barrel(6) through the screen sleeve(7). During down-stroke, the pressure on the upper part of the standing valve is increased, the valve ball(4) is closed, and the well fluid enters the upper tubing of the pump and is lifted to the surface.
The sand in the well fluid sinks under the influence of its own gravity and is fixed along the The cone surface of the valve cage(3) sinks into the tail pipe(9) through the sand trap barrel joint(6) to prevent sand from burying the standing valve. At the same time, because the standing valve cage(3), valve ball(4) and valve seat(5) are installed on the upper part of the sand trap barrel joint(6) and are suspended.The thread of the standing valve cage(3) which is pressing valve seat(5) does not bear the axial tensile force, eliminating the loosening of the valve pair, avoiding the puncture of the valve seat(5) end face, improving the sealing performance of the valve pair, and prolonging the maintenance-free period of the oil well.