RU2085707C1 - Device for metered delivery of reagent into well equipped with rod-type pump - Google Patents

Abstract

FIELD: oil production industry. SUBSTANCE: metering unit is located between rod-type pump and container for reagent. Container is provided with divider made in the form of float from hollow cylinder filled with liquid ensuring its floatability. Valve is rigidly connected with rod brought into action due to liquid pressure differential occurred during operation of rod-type pump. This device allows for metered delivery of demulsifier proportionally to liquid flow rate. This operation saves demulsifier, reagent is not mixed with reservoir liquid, that is concentration of demulsifier remains unchanged. EFFECT: high efficiency. 1 dwg

Description

 The invention relates to the oil industry and can be used in oil production.

 The most effective use of reagents (inhibitors, demulsifiers, additives that prevent deposition of paraffins and salts in the well string) is their introduction into the bottom of the well, i.e. at the very beginning of the movement of the oil-water mixture.

 Closest to the proposed device is a deep pump installation for oil production and downhole processing of oil (Aut. St. N 966229, E 21 B 43/00, 1980), which is a plunger pump for dosing the reagent in the bottom of the well, operating due to cyclical changes in the length of the column pipes during the operation of the sucker rod pump. The dispenser includes a reagent tank with a piston, a cylinder, a plunger, suction and discharge valves, a cam pusher of the plunger. The stroke of the plunger is set by the adjusting screw until the dispenser is lowered into the well, corresponding to the given reagent supply. The plunger of the dosing device is driven by cyclic extension and shortening of the pipe string during the operation of the sucker rod pump.

 The disadvantage of this device is the difficulty of adjustment depending on the elongation of the column, because elongation of the column is secondary to the operation of the sucker rod pump, which greatly reduces the reliability of the device, and the design of the device is complex.

 Placing the container for the reagent above the dosing device leads to the fact that the reagent is taken from below, and the replacement reservoir fluid enters the container from above. Since usually the formation fluid has a density greater than the reagent, favorable conditions are created for mixing the reagent with the formation fluid. The presence of an insulating piston does not completely eliminate their mixing, since the piston does not provide complete tightness of the isolation of the interface between the reagent and produced water in the container.

 In order to increase the reliability of the metering device, a device for dosing the reagent into a well equipped with a rod pump is proposed, comprising a reagent container equipped with a reagent separator from the formation fluid and a metering unit with a valve, characterized in that the metering unit is located between the rod pump and the container for reagent, the valve is made in the form of a rigidly connected valve, stem and disk, actuated from the differential pressure of the reservoir fluid during the operation of the sucker rod pump, and the reagent separator from the formation fluid is made in the form of a float from a hollow cylinder filled with fluid with a density that ensures its buoyancy in the reservoir fluid.

 Such a technical solution simplifies the design of the dosing device, increases the reliability of operation and guarantees a predetermined dosage of the reagent.

 The drawing shows the proposed device.

 The device consists of a container 1 for the reagent in the form of a section of a tubing of the required length with a bottom 2, a separator of the reagent from the reservoir fluid 3, a section of a tubing 4 with windows 5, a seat 6, a valve 7, a rod 8, a disk 9, a support the ring 10, the support of the guide rod 11, the limiter-regulator of the stroke of the valve 12, the coupling for connecting the tubing 13.

 The device operates as follows.

 The dosing unit is located directly below the sucker rod pump in the tubing with a window at this level for the receipt of well production. A container 1 for the reagent is placed under the dosing unit. The device lowers into the well while lowering the sucker rod pump into the well. The container 1 is filled with a reagent at the wellhead in a suspended state of the container on the head of the well. In this case, the separator 3 of the reagent from the formation fluid is in the lower position and at the same time closes the hole in the bottom 2 and prevents leakage of the reagent. The device is pre-assembled inside a segment of the tubing 4. This pipe section has windows 5 for the formation fluid to enter the suction valve of the rod pump. In the lower part of this pipe segment, a valve seat 6 is located with a calibrated hole, which is blocked by a valve 7, which is connected by a disk 9 using a rod 8. When the valve 7 is in the lower position, the disk 9 rests on the support ring 10. The rod 8 has a guide support 11, and the stroke the valve is regulated by a limiter-regulator 12. The segments of the tubing are connected in one column using a sleeve 13.

 In this form, the assembled tubing string and sucker rod pump are lowered into the well.

 During the operation of the sucker rod pump, when the pump is sucked in by the liquid, by creating a differential pressure of the liquid, the disk 9 rises within the set stroke and opens a hole in the valve seat 6, through which the reagent is squeezed out due to the pressure of the formation fluid entering the reagent tank through the hole in the bottom 2 containers 1. This dose of reagent, together with the formation fluid entering through the windows in the pipe, is pumped into the suction. The dosage of the reagent depends on the cross section of the hole in the valve seat 6, the time the valve is open and the frequency of the piston stroke of the pump. The cross section of the hole in the valve seat 6 is controlled by restricting the rise of the valve 7 using the limiter-regulator 12 of the stroke of the valve 7, and the time spent by the valve open directly depends on the length of the suction time of the pump and is determined by the stroke length of the pump drive. Thus, dosing of the reagent is achieved depending on the performance of the sucker rod pump. In this case, dosing of the reagent occurs only when the pump is running. When the pump does not work, valve 7 remains closed and no reagent flows.

 When reagent is consumed, formation fluid enters the reagent tank through the bottom opening. In this case, the separator 3 is located at the interface between the reagent and the formation fluid, since it is made of a material with a density greater than the density of the reagent, but less than the density of the formation fluid, i.e. the separator sinks in the reagent, but floats in the reservoir fluid. The separator prevents mixing of the reagent with the reservoir fluid and helps to maintain a constant concentration of the reagent in the container.

Claims (1)

 A device for dosed supply of reagent into a well equipped with a rod pump, comprising a container for reagent, equipped with a separator of reagent from the reservoir fluid, and a dosing unit with a valve, characterized in that the dosing unit is placed between the rod pump and the container for reagent, the valve is made in the form of a rigid actually connected valve, stem and disk, driven by the differential pressure of the reservoir fluid during operation of the sucker rod pump, and the separator of the reagent from the reservoir fluid It is filled in the form of a float from a hollow cylinder filled with a fluid with a density that ensures its buoyancy in the reservoir fluid.