RU2135743C1 - Well metering pump installation - Google Patents

Abstract

FIELD: oil production, use of wells with metered feed of reagents to pump inlet. SUBSTANCE: pump installation has dynamic action pump, chemical reagent container of " tube in tube " type, jet device operated as metering device. Jet device and container are positioned under pump. They are fitted with non-return valves of ball-spring " type. Valve for inlet of internal tube has stiffer spring or lighter ball as compared with valve for inlet of jet device. Produced fluid is directed to nozzle of jet device. Non-return valve of it opens. Valve at inlet of container also opens. Chemical reagent will be driven by fluid from beneath. Metering is conducted by selection of diameters of nozzle and neck. EFFECT: increased operational efficiency of installation while pumps of dynamic action are used for oil production. 1 cl, 1 dwg

Description

 The invention relates to techniques for oil production, in particular to well installations, and can be used in the oil industry for the operation of wells that require a dosed supply of a chemical agent to receive the main pump.

 The closest in technical essence to the invention is a borehole dosing pump unit operating with a volumetric pump [1]. The installation includes a volumetric pump and a dispenser installed in the column of pumping pipes; dosing plunger, suction chamber, chemical container and a system of nozzles and valves. The container is pre-filled with a chemical agent. During operation of the main pump, rarefaction occurs in the lower cavity and the metering plunger is driven. The chemical reagent through the system of channels and valves enters the main pump, mixing with the well fluid. When the plunger moves downward, excess pressure closes the valve, which prevents the penetration of liquid into the container with the reagent. Next, the cycle repeats.

 To prevent complications (corrosion, deposition of salts and paraffins, and so on) in the process of producing well products using dynamic pumps (ESP, GOS, turboprop, etc.), the use of this installation is impossible. The reason is the principle of operation (continuous) and the design features of dynamic-acting pumps.

 The task at hand is to ensure the efficiency of a borehole dosing pump installation during the operation of wells with dynamic action pumps.

 The problem is solved in that the dynamic action pump is installed as the main pump, the chemical container is of the “pipe in pipe” type, the jet device is installed as a dispenser, and the jet device and the inner pipe are equipped with a check valve type “ ball-spring "and the valve at the inlet of the inner pipe has a stiffer spring or a lighter ball compared to the valve at the inlet of the inkjet apparatus, and the nozzle and neck of the inkjet apparatus are made with a diameter of the current volume of produced fluid and the required dosage of the chemical.

 An inkjet installation as an independent structure is often used for producing liquid from wells, for developing wells after drilling, as an additional pump to the main one (tandem systems), and also as an ejector for mixing various substances in the same and different aggregate states (liquid + liquid, gas + gas, liquid + gas). However, the use of an inkjet unit as a metering pump for production with dynamic action pumps to prevent complications has not yet been described.

 Known pump-ejector system containing an ESP, a gas separator and a jet apparatus located in the discharge line of the ESP. The gas-liquid mixture arrives from the wellbore to receive an electric pump unit, then part of the product is separated due to both natural and artificial separation into the annulus of the well. After the separator, a mixture with residual gas and low oil content is sent to the submersible centrifugal pump. The pump pumps this product into the flow line and further into the working nozzle of the jet apparatus. The ejector pumps the gas-liquid mixture from the annulus into the tubing and then to the surface. Thus, in this case, the ejector plays the role of an additional pump to the main one and, therefore, the system is conventionally called "Tandem" [2].

 But in this design, the inkjet apparatus plays the role of only a pump that facilitates the operation of the main one, and the chemical is not supplied to the produced fluid to prevent complications.

 In FIG. schematically shows a General view of the dosing unit.

 A downhole jet pump installation includes a jet apparatus 2 mounted in a column of pump pipes 1, consisting of a neck 3 and a nozzle 4 located inside a container for chemicals 5, also inside this container there is a second container 6. At the inlet of the nozzle of the jet apparatus and at the inlet of the inner container there are check valves 7 and 8 of the type "ball-spring", for communication between the produced fluid and containers there are openings 9 and 10, and 11 is a dynamic pump.

 The proposed downhole installation works as follows.

 Before the equipment is lowered into the well, the container 5 is filled with a chemical reagent, and the container 6 is filled with retaining liquid (killing liquid) with a density higher than the produced liquid. The internal volumes of containers 5 and 6 are the same. The differential pressure at which the valve 7 opens is slightly less than the differential pressure that opens the valve 8 due to the specified spring stiffness or ball weight. Therefore, the produced fluid, which acts as the working fluid for the dosing pump, will be directed through the opening 9 into the nozzle 4, when a certain pressure drop is reached, valve 7 will open, then 8. Thus, the chemical will always be pressurized from below by the fluid. The dosage of the incoming chemical in the produced fluid is carried out by selecting the diameters of the nozzle 3 and the neck 4, knowing the required concentration in advance. As the chemical is consumed from the container 5, it will be filled with retaining liquid, and the container 6 through the hole 10 with the produced liquid. The holes 11 located in the lower part of the container 6 are used for communication between the two cavities of the containers 5 and 6. This design will avoid getting the produced fluid directly to the intake of the dosing pump and hold the oil in the upper part of the container 6 until the chemical has been used up.

 Thus, the use of the proposed design allows for the metered supply of a chemical reagent to the produced well products during operation by pumps with dynamic action to prevent complications.

 The device is industrially applicable, since all its components and parts are manufactured by industry and can be manufactured in an industrial environment.

Sources of information:
1. USSR author's certificate N 1617198 A1, cl. F 04 B 47/00, 1990.

 2. Drozdov A.N., Andriyanov A.V. Pilot industrial introduction of submersible pump-ejector systems in NGDU "Fedorovskneft". // Oil industry.-1997. N 1. S. 51-54.

Claims (2)

 1. A downhole dosing pump installation comprising a main pump installed in a column of pump pipes and a dispenser and a chemical container placed underneath it, check valves, characterized in that a dynamic action pump is installed as the main pump, the chemical container is made in the form of a “pipe in pipe” , an inkjet apparatus is installed as a dispenser, moreover, the inkjet apparatus and the inner pipe are equipped with a ball-spring check valve at the inlet of the produced fluid and a valve at the inlet of the inner pipe has ie stiffer spring or lighter ball than with a valve at the input of the jet device.  2. The downhole dosing pump installation according to claim 1, characterized in that the nozzle and neck of the inkjet apparatus are made with a diameter corresponding to the volume of the produced fluid and the required dosage of the chemical agent.