RU2450119C1 - Equipment complex for production of high-viscosity oil - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: equipment complex for production of high-viscosity oil comprises a lifting pipe with an oil pump drive installed inside and a mounted assembly from an oil pump, a perforated section of a pipe with a pump anchor and a well device. The well device is made in the form of a cylindrical vessel, in which there is a tight cavity and a circular chamber serially arranged with radial channels in its vessel. Besides, in the tight cavity there is a source of elastic oscillations of high frequency made as an ultrasonic converter of circular shape. The tight cavity along the assembly axis is equipped with a brace having an inner through channel leading to a circular chamber. The well device is connected with an electric cable to a ground power supply source. At the same time the complex is complemented with a ground pump, a line of liquid chemical reagent supply via an inner channel of the tight cavity brace into the circular chamber. The perforated channel of the pipe between the oil pump and the pump anchor is equipped with a hole for supply of a power supply cable and a chemical reagent supply line.

EFFECT: higher efficiency of ultrasonic treatment due to intensified additional chemical impact at oil into a casing pipe.

4 cl, 2 dwg, 3 tbl, 1 ex

Description

The invention relates to the field of oil production, in particular to the production of highly viscous oil using the energy of elastic vibrations, increasing the efficiency of ultrasonic processing due to the intensification of the additional chemical effect on oil in the casing, and can be implemented when working in conditions of low climatic temperatures.

The use of the invention provides both the production of highly viscous oil and its transportation to main pipelines.

The main methods for the development of viscous oils are thermal, gas, chemical and physical using which, for example, in 2000, 122 million tons of heavy and bituminous oil were produced in the world.

In practice, the rheological characteristics of high-viscosity oil are usually reduced by dilution with lighter solvents, oil, gas condensate. The main reason for the anomalous viscosity of heavy oils and natural bitumen is considered to be a high content of tar-asphaltene components (NAO) in them, upon reaching a critical concentration of which a sharp change in rheological properties occurs and structural-mechanical properties begin to manifest themselves to a large extent, which is explained by intermolecular interactions of NAO [M .Yu.Dolomatov, A.G. Telin, N.I. Khisamutdinov. Physicochemical fundamentals of the directional selection of solvents of asphalt-resinous substances // M .: TSNIITENeftekhim. - 1991. - 47 p.].

A known method of preparing highly viscous heavy oil for transport [SU 1366772], which allows to improve the rheological properties of oil by treatment with 0.01 ÷ 0.03% alcohol solution of alkali at a mass ratio of oil and solution (100 ÷ 150): 1 and heat treatment at 40 ÷ 50 ° C. In this case, the kinematic viscosity decreases by 20–30% due to a change in the molecular mobility of the group components of oil disperse systems.

The disadvantage of this method is the need for additional equipment for heat treatment.

As for the treatment of the bottom-hole zone of production wells with oil solvents [Zaripov I.Z., Mustafin GG, Yusupov I.G., Goryunov V.A. Treatment of the bottomhole formation zone with a heated solvent // Oilfield business. No. 9. S.8-9; Zaripov I.Z., Sivukhin A.A., Ivanov A.I. The treatment of the bottom-hole zone of the layers of producing wells with a solvent without lifting the underground equipment // Oilfield business. - 1981. No. 6. S.31-32], then, as a rule, this leads to in-situ deasphalting of oils containing a large amount of asphaltenes. The use of such solvents also increases the fire and explosion hazard during field operations.

A device for producing highly viscous oil is known [RU 2008133099], including a tubing string located in a production string perforated at the level of the oil reservoir, a well pump installed inside the tubing, a metering line for delivering a low-viscosity substance to the annulus of the tubing and diluted oil outlet line for diluting highly viscous oil.

The disadvantage of this device is the relatively complex hardware design, namely, that the tubing string is made in the form of two concentrically arranged tubing tubing columns, while at the lower end of the tubing with a large diameter, a mixing unit and a medium separator are fixed.

The second disadvantage is the relatively low activity of a low-viscosity substance, while the known method of increasing activity by simultaneous or sequential exposure of a substance [RU 2246525], wave electromagnetic and acoustic fields with energy and frequencies corresponding to resonant frequencies and / or vibration frequency of molecules of organic compounds.

The preparation of high-viscosity oil for production and transport is increasingly carried out on the basis of deliberate changes in the balance of forces of intermolecular interaction in order to control the degree of dispersion of the oil system through the combined effects of chemicals and ultrasound.

It is known that to reduce the viscosity of oil, you can use a source of high-frequency electromagnetic field [Shiryaeva R.N., Kudasheva F.Kh., Gimaev R.N., Sagitova Ch.Kh. On the rheological properties of oils with a high content of resins and asphaltenes. Chemistry and technology of fuels and oils, 3, 2006].

It was established [A. Vladimirov. Development of wave technology and equipment for the transport of high-viscosity oils and petroleum products // Account number in the source database 022000500271. - State registration number. - 01200307565. - 01/17/2005], that the influence of the ultrasonic field leads to a decrease in the viscosity of oils at a temperature of 25 ° C to the values characteristic of these oils when they are heated at temperatures of 40 ÷ 50 ° C and above.

A device is known [RU 9305476], which generates ultrasonic energy to reduce the viscosity of oil. An electro-acoustic transducer of ultrasonic energy converts the signals of an alternating electric current of the selected voltage into ultrasonic energy, the transducer being located in the material being processed and having an acoustic connection with it.

The disadvantage is that the use of only a high-frequency electromagnetic field to improve the rheological properties of oils with a high content of resinous-asphaltene substances is not always advisable due to the polarization of resinous components in the electromagnetic field and, as a result, the formation of large associates that increase the viscosity of oil.

A known installation [RU 2026969], in which the downhole tool is connected to a ground source of industrial frequency power and contains one emitting ultrasonic piezoelectric transducer having a fairly narrow amplitude-frequency characteristic and providing the creation of high-frequency elastic vibrations at its resonant frequency.

A common significant disadvantage of using only the electromagnetic field is the reversibility of the effect. So, it is known [US 2008257414] that the application of an electric field of 6 ÷ 10 kV / cm for 60 seconds can reduce the viscosity of heavy oily fractions by 17 ÷ 20%, however, after 30 minutes the viscosity is restored by half, and after 8 ÷ 10 hours completely, which limits the use of this technology for the preparation of highly viscous oil for transportation through pipelines.

In the known method [RU 2108452] for chemical treatment of a formation using downhole ultrasonic generators, first tubing - tubing is lowered down the well to the bottom, the treatment composition is pumped over it, then the pipes are raised to the surface, and lowered into the well and placed against the interval being treated formation emitter of ultrasonic waves. Ultrasound treatment of the formation and the well is carried out in an environment of this composition.

A significant drawback of this method from an economic point of view is the high consumption of the processing compound. Also, this method does not allow, without additional descent, lifting the equipment to remove the products of destruction of asphalt-resin-paraffin deposits - paraffin deposits and clogging impurities, which, of course, reduces the processing efficiency.

Closest to the proposed invention by technical essence is a set of equipment for implementing the method of complex processing of the bottomhole zone of the well [RU 2261986] (prototype), including a layout with an ultrasonic generator that is lowered into the well on a tubing string.

A pump is included in the composition of the assembly that is lowered into the well on the tubing string, then a perforated pipe section with a downhole apparatus containing an ultrasonic generator. The annulus above the perforation interval is disconnected by the packer.

Ultrasonic action on the bottomhole zone of the well by elastic vibrations of ultrasonic frequency is carried out in an environment of an active process fluid and an acid solution. As an active process fluid, a solvent of asphaltene-tar-paraffin deposits is used.

The disadvantage of this complex is that it requires preliminary sale of the acid solution into the formation with technological exposure for the reaction of the acid. And only then do the formation drainage with the creation of alternating fluid movement in the interval of perforation and weak depressive pulses with constant exposure to the formation by ultrasound with pumping of reaction products and simultaneous washing out of the treatment products. The cyclical process is obvious.

The second disadvantage is that the ultrasound effect is carried out in the interval of perforation of the tubing, while it is useful to affect the entire area of the reservoir, in particular the fluid located in the annulus of the casing of the well and tubing.

The technical problem is the effective integrated effect of ultrasound and chemical reagents on the rheological properties of oils with different contents of resinous-asphaltene components.

The invention is aimed at creating equipment that allows continuously using ultrasound-activated chemical reagent to significantly reduce the viscosity of oil of various fields directly in the annular space of the well casing and tubing and to maintain viscosity characteristics in time sufficient for transporting produced oil through pipelines.

The technical result is achieved by the fact that a complex of equipment for the production of highly viscous oil is proposed, comprising a tubing with an oil pump drive located inside it and a serial arrangement of an oil pump, a perforated pipe section with a pump anchor and a borehole apparatus made in the form of a cylindrical a housing in which a sealed cavity and an annular chamber with radial channels in its housing are arranged in series, a source is placed in a sealed cavity IR of high-frequency elastic vibrations made in the form of a ring-shaped ultrasonic transducer, the hermetic cavity along the axis of the assembly is equipped with a coupler having an internal through channel leading to the annular chamber, the borehole apparatus is connected by an electric cable to a ground power source, and the complex is supplemented with a line equipped with a ground pump supply of a liquid chemical reagent through the internal channel of the tightness cavity screed into the annular chamber, and the perforated pipe section between the oil pump and the armature of the pump is provided with a hole for the cable supplying power supply line and the chemical reagent.

It is advisable that the supply line of the liquid chemical reagent to the inner channel of the screed is sealed with cuffs.

It is also advisable that the connection of the screed cavity and the bottom of the annular chamber is sealed with ring seals.

It is important that the sealed cavity of the downhole tool is filled with a liquid electrically insulating medium, mainly a heat-resistant organosilicon liquid.

The essence of the proposed complex lies in the fact that the ultrasonic effect on the rheological properties of oil is carried out in the environment of an activated liquid chemical reagent directly in the annulus of the casing of the well and tubing.

To increase the efficiency, a single source of high-frequency elastic vibrations simultaneously acts both on a liquid chemical reagent until it is diluted with highly viscous oil, and on the mixed composition of oil with a pre-activated chemical reagent.

It was experimentally established that the best indicators of effective viscosity are achieved when exposed to a chemical reagent preactivated by ultrasound. The results are presented in Table 1: “Values of effective oil viscosity of the Verkhne-Salatsky oil field of the Kargasoksky district of the Tomsk region, depending on the types of exposure to oil.”

Table 1 Sample Viscosity (MPa · s) at 20 ° C Oil source 295 Oil + 1% toluene 224 Oil + ultrasound (1 min) 249 Oil + 1% toluene + ultrasound (1 min) 171 Oil + 1% toluene pretreated with ultrasound (0.5 min) + ultrasound (1 min) 152

Placing the channels for the withdrawal of chemical reagents into the casing of the well below the source of high-frequency elastic vibrations allows the complex chemical-physical effect on the entire volume of the dynamic level of oil during the operation of the oil pump.

The invention is illustrated in FIG. 1: Diagram of a complex of equipment for the production of highly viscous oil, and FIG. 2: Schematic diagram of a downhole apparatus,

on which: 1 - tubing; 2 - oil pump drive; 3 - oil pump; 4 - perforated pipe section; 5 - pump armature; 6 - downhole apparatus; 7 - electric power cable of the downhole apparatus; 8 - ground power source of the downhole apparatus; 9 - supply line of a liquid chemical reagent; 10 - ground chemical feed pump; 11 - sealed cavity; 12 - ultrasonic transducer ring shape; 13 - an annular chamber with radial channels in the housing of the downhole apparatus; 14 - ring seals; 15 - coupler sealed cavity having an internal through channel; 16 - cuffs; 17 - hole for supplying the power cable and chemical feed line.

As an oil pump, both screw and sucker-rod pumps can be used.

The use of a section of the tubing perforated between the pump and the borehole apparatus allows oil to be taken from the casing.

The pump anchor is designed to fix the oil pump below the dynamic oil level in the casing, as well as to compensate for torque in the case of a screw pump. The petal design of the anchor does not impede the movement of oil through the casing.

The downhole tool, connected to the perforated pipe section by a threaded fastener, is designed for complex chemical and physical effects on the oil entering the casing. In this case, preliminary activation of the chemical reagent by ultrasound is additionally carried out.

The chemical reagent supply line and the power cable of the downhole apparatus are led to the downhole apparatus through an opening in the perforated pipe section located between the oil pump and the pump armature, which prevents them from breaking through the armature petals in case of possible rotation.

The sealed cavity is designed to accommodate an ultrasonic transducer in it, the operating conditions of which include filling the cavity with a liquid electrically insulating medium.

The use of an annular chamber allows the accumulation of a chemical reagent activated by ultrasound so that it can be continuously fed into the casing through radial channels in the body of the downhole tool.

The screed of the sealed cavity, being a structural element, has an additional function, which consists in the fact that the chemical reagent passes through the zone of the ultrasonic influence through the inner through channel of the screed.

The complex works as follows (Figs. 1 and 2).

On the surface, the tubing 1 is equipped with a drive of the oil pump 2, then the arrangement of the oil pump 3, the perforated section of the pipe 4 with the anchor of the pump 5 and the downhole apparatus 6, made in the form of a cylindrical body, is sequentially mounted on the pipe. The tubing 1 with the specified arrangement is lowered into the casing of the well to a depth at which the well apparatus 6 is located in the zone of the reservoir. By means of an electrical power cable of the downhole apparatus 7, power is supplied to the downhole apparatus 6 from a ground source 8. Through the supply line of the liquid chemical reagent 9 by the surface pump 10, the reagent enters the screed channel 15 of the sealed cavity 11 of the downhole apparatus 6, where the reactant is activated by ultrasound from the ultrasonic transducer annular form 12 located in the specified sealed cavity 11. Next, the activated chemical reagent enters the annular chamber 13, and from measures through radial channels in the body of the downhole apparatus into the annulus filled with oil. The tightness of the cavity 11 is ensured by the fact that the connection of the screed 15 with the bottom annular chamber 13 is provided with ring seals 14, and the supply line of the liquid chemical reagent 9 to the inner channel of the screed 15 is made by a cuff connection 16. To supply the power cable and the supply line of the chemical reagent, the perforated section the pipe is provided with a hole 17.

A mixture of oil with an activated chemical reagent under the action of the oil pump 2 rises to the perforated section of the pipe 4, flowing around the cylindrical body of the downhole apparatus 6, in the zone of which ultrasonic treatment of the produced oil in the medium of the activated chemical reagent is carried out.

The following is an example of achieving a technical result when using the inventive complex of equipment for the production of highly viscous oil. The example illustrates, but does not limit the application of the proposed complex.

Example 1. As an example, below are the data of laboratory studies of oil of the Luzanovskoye field of the Samara region and field data of the claimed complex.

Luzanovskaya oil is highly viscous and is characterized by the following indicators: effective viscosity at 20 ° C - 1014 MPa · s; freezing temperature - minus 17 ° C; oil content - 64.1 wt.%; the resin content is 28.6 wt.%; the content of asphaltenes is 6.1 wt.%.

Studies of changes in viscosity by the nature of the chemical reagent showed that the best results were obtained with the use of toluene pre-activated by ultrasound, followed by ultrasonic exposure to oil in an environment of activated toluene.

The results are presented in Table 2: “Values of the effective viscosity of the oil of the Luzanovskoye field depending on the nature of the chemical reagent and its activation by ultrasound.”

table 2 Sample Viscosity, MPa · s Without activating the reagent with ultrasound With preliminary activation of the reagent by ultrasound 0.5 min Source oil 1014 Oil + 1% methanol 744 707 Oil + 2% methanol 697 635 Oil + 1% solvent R-12 * 701 671 Oil + 2% solvent R-12 559 490 Oil + 1% toluene 686 488 Oil + 2% toluene 642 429 * solvent R-12, wt.%: Butyl acetate - 30; Toluene - 60; Xylene - 10

Qualitative indicators of the use of the equipment complex are shown in Table 3: “Values of the effective oil viscosity of the Luzanovskoye field depending on the time elapsed after its production by the claimed equipment complex at different toluene contents”.

Table 3 The toluene content,% The time elapsed after oil production, hours Ref. 0 24 48 72 Dynamic viscosity, MPa · s 0.2 1014 847 887 912 915 0.5 1014 772 795 810 815 one 1014 488 515 680 690 1,5 1014 449 480 490 495

As can be seen from Table 3, the ultrasonic effect on the oil mixture with pre-activated ultrasound toluene also significantly reduced the viscosity of the oil directly in the annular space of the well casing and tubing and saved the viscosity characteristics in time sufficient for transporting oil to the main pipelines.

Claims (4)

1. A complex of equipment for the production of high-viscosity oil, containing a tubing with an oil pump drive located inside it and a serial assembly of an oil pump, a perforated pipe section with a pump anchor and a borehole apparatus made in the form of a cylindrical body, in which a sealed cavity and an annular chamber with radial channels in its housing are located; a source of high-frequency elastic vibrations made in in the form of an ultrasonic transducer of a circular shape, the sealed cavity along the assembly axis is equipped with a screed with an internal through channel leading to the annular chamber, the downhole apparatus is connected by an electric cable to a ground power source, and the complex is supplemented by a liquid chemical reagent supply line through the ground screed channel equipped with a ground pump a tight cavity in the annular chamber, and the perforated pipe section between the oil pump and the pump armature is provided with an opening for supplying cable A power supply line and the chemical reagent. 2. The complex according to claim 1, characterized in that the supply line of the liquid chemical reagent to the inner channel of the screed is sealed with cuffs. 3. The complex according to claim 1, characterized in that the connection of the screed cavity and the bottom of the annular chamber is sealed with ring seals. 4. The complex according to claim 1, characterized in that the sealed cavity of the downhole tool is filled with a liquid electrically insulating medium, mainly a heat-resistant organosilicon liquid.

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