RU2594910C1 - Device to prevent formation of paraffin and hydrate deposits in oil wells - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to oil production and can be used for heating of high-viscosity and waxy oil directly in the well. Device for prevention of formation of paraffin and hydrate deposits in oil wells contains heat generator connected through suction and pressure pipelines of circulation pump to well heater, which is integral part of tubing string. Wherein heater is a housing consisting of outer and inner walls, mounted coaxially with annular gap and forming a cavity for heating coolant, supply and discharge manifold with nozzles, inside of which there is an additional heat exchange element. Additional heat exchange element is composed of two cylindrical shells installed coaxially and connected to each other. Wherein at the ends of additional heat exchanging element there are pylons, in which there are channels for supply and removal of heating coolant.

EFFECT: technical result is increasing efficiency of production of high viscous and paraffin oil.

1 cl, 4 dwg

Description

The invention relates to the field of oil production and can be used to heat highly viscous and paraffin oil directly in the well.

One of the main problems encountered during oil production and causing complications in the operation of wells, oilfield equipment and pipeline communications are asphalt-tar-paraffin and hydrated deposits.

A well heater is known, comprising a cylindrical tubular body, inside of which a portion of the pipe of the suspension of the tubing is coaxially placed, on the outer surface of which along the pipe spaced apart induction cylindrical coils are connected via an electrical connection cable to an AC source located on the surface (RF patent No. 2317401, IPC: E21B 36/00 - prototype).

The specified downhole heater operates as follows.

When AC is supplied through an connecting electric cable to induction cylindrical coils in the pipe section from the suspension of the tubing, induced alternating magnetic fluxes induce currents, which can be considered as eddy or as a short circuit current of the secondary winding of the transformer having one turn. This current heats the pipe section from the suspension of the tubing, the heat from which is discharged by the flowing oil to be heated.

The main disadvantage of this downhole heater is its low heat output.

The objective of the invention is to prevent the formation of asphalt, resin and hydrate deposits in the tubing of production wells by heating high-viscosity and paraffin oil directly in the well.

The solution to this problem is achieved by the fact that the proposed device for preventing the formation of asphalt-resin-paraffin and hydrate deposits in oil wells according to the invention contains a heat generator connected by means of a suction and pressure pipe of the circulation pump with a downhole heater, which is an integral part of the tubing and is a casing consisting of the outer and inner walls mounted coaxially with the annular gap and forming a cavity for heating medium, inlet and outlet manifold with nozzles, in the inner cavity of which an additional heat exchange element is installed, made in the form of two cylindrical shells mounted coaxially and interconnected, while at the ends of the additional heat exchange element there are pylons in which channels for supply and removal of the heating coolant.

In an embodiment, the pylons located on the oil supply side are mounted at an angle to the longitudinal axis of the housing.

The invention is illustrated by drawings, where in FIG. 1 shows a diagram of a device for preventing the formation of asphalt-resin-paraffin and hydrate deposits in oil wells, FIG. 2 is a longitudinal section through a borehole heater; FIG. 3 - section AA - cross section of the downhole heater, in FIG. 4 - remote element B is a longitudinal section of a downhole heater.

The proposed device contains a heat generator 1 connected by means of a suction and pressure pipe of the circulation pump 2 with a downhole heater 3.

The downhole heater 3 is an integral part of the tubing 4 and is a housing 5 consisting of an outer wall 6 and an inner wall 7 mounted coaxially with an annular gap and forming a cavity for the heating fluid, the inlet manifold 8 and the outlet manifold 9 with nozzles, in the inner cavity of which has an additional heat exchange element 10, made in the form of two cylindrical shells 11 and 12, mounted coaxially and interconnected, while at the ends of the additional Of the heat-exchange element 10, pylons 13 are located in which channels 14 are made for supplying and discharging the heating coolant.

In an embodiment, the pylons 13 located on the oil supply side are installed at an angle to the longitudinal axis of the housing 5.

The proposed device operates as follows.

The downhole heater 3 is connected via couplings to the tubing 4.

Oil is supplied into the internal cavity of the housing 5 of the downhole heater 3. Oil is evenly distributed in the inner cavity of the housing 5 and moves in an annular gap located between the cylindrical shell 12 of the additional heat exchange element 10 and the inner wall 7 of the housing 5, as well as in the inner cavity of the cylindrical shell 11.

In the heat generator 1, liquid or gaseous fuel is burned. The resulting fuel combustion products transfer their heat to the heating coolant filling the heat generator 1.

The heating fluid from the heat source 1 through the suction and pressure pipes of the circulation pump 2 enters the supply manifold 8 of the downhole heater 3 and then into the annular gap located between the outer wall 6 and the inner wall 7 of the housing 5. In the annular gap, the heating fluid is divided into two streams.

The first flow of the heating fluid passes in the annular gap between the outer wall 6 and the inner wall 7 of the housing 5, is cooled, giving heat to the oil flow moving in the internal cavity of the housing 5, and is diverted to the exhaust manifold 9.

The second flow of the heating fluid enters through the channels 14, made in the pylons 13, into the annular gap located between the cylindrical shells 11 and 12 of the additional heat exchange element 10. Passing along the annular gap, the heating fluid is cooled, giving heat to the oil flow moving in the internal cavity of the housing 5 , after which the flow through channels 14 enters the outlet manifold 9.

In the exhaust manifold 9, two flows of the heating fluid are mixed together. The heating coolant comes from the exhaust manifold 9 to the heat generator 1.

In an embodiment, the oil flow passing through the pylons 13, mounted at an angle to the longitudinal axis of the housing 5, acquires a rotational movement, which allows to intensify the heat transfer process.

The use of the present invention will prevent the formation of asphalt-resin-paraffin and hydrate deposits in the tubing of production wells by heating high-viscosity and paraffin oil directly in the well.

Claims (2)

1. A device for preventing the formation of asphalt, resin and hydrate deposits in oil wells, characterized in that it contains a heat generator connected by means of a suction and pressure pipe of the circulation pump to the well heater, which is an integral part of the tubing and is a housing consisting of outer and inner walls installed coaxially with an annular gap and forming a cavity for a heating coolant, inlet and outlet a manifold with nozzles, in the interior of which an additional heat exchange element in the form of two cylindrical shells, installed coaxially and interconnected with the ends of an additional heat exchange element disposed pylons, which has channels for the supply and discharge of heating medium. 2. The device according to claim 1, characterized in that the pylons located on the oil supply side are installed at an angle to the longitudinal axis of the housing.

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