CN215001539U - On-line cleaning system for high-pressure steam injection boiler of oil field - Google Patents

Abstract

The utility model relates to a scaling cleaning technology for a high-pressure steam injection boiler used in an oil field, in particular to an on-line cleaning system for the high-pressure steam injection boiler used in the oil field, which comprises a dosing tank, a centrifugal pump and a steam injection boiler system device, wherein the dosing tank is communicated with a plunger pump through a dosing pipeline via the centrifugal pump and is communicated with a feed water preheater, a convection section, a superheating section and a radiation section pipeline via pipelines; the outlet of the radiation section is communicated with a steam-water separation device through a pipeline and a sampling separator, and the outlet of the overheating section is communicated with a steam injection shaft through a pipeline and a water spray desuperheater; the dry steam outlet of the steam-water separator is communicated with the overheating section through a pipeline, and the saturated water outlet of the steam-water separator is communicated with the steam injection shaft through a pipeline and a water spray desuperheater. The utility model discloses simple structure, economical and practical does not need the blowing out, utilizes the front end to add the medicinal cupping and carries out the water injection and dose, and the medicament is along with water injection steam flow direction, makes each minute part boiler pipe internal scale deposit of high pressure steam injection boiler obtain dissolving, improves boiler work efficiency.

Description

On-line cleaning system for high-pressure steam injection boiler of oil field

Technical Field

The utility model relates to an oil field is with high-pressure steam injection boiler scale deposit washing technical field, is an online cleaning system for oil field high-pressure steam injection boiler.

Background

The heavy oil is also called heavy oil, namely high-viscosity heavy crude oil, the viscosity of the heavy oil in an oil layer is high, the flow resistance is large, even the heavy oil cannot flow, and the conventional technology is difficult to economically and effectively develop a heavy oil field; the process for exploiting the thick oil by injecting steam can greatly increase the yield of the thick oil, and the high-pressure steam-injection boiler generates high-pressure high-temperature steam to be forcibly fed into a stratum, so that the viscosity of crude oil is reduced, the fluidity of the crude oil is increased, and the recovery ratio is improved. The main development mode of thickened oil in the oilfield operation area in Xinjiang is steam injection thermal recovery, and a plurality of high-pressure steam injection boilers are built.

During the operation of the high-pressure steam injection boiler, the operation pressure difference is high due to scaling in a boiler tube, the normal operation of the steam injection boiler is influenced, the boiler pressure difference is increased, the tube bundle of a boiler body is easily blocked and exploded, and the heat absorption capacity of the boiler is influenced, so that the fuel consumption is increased. The conventional cleaning method adopted at present needs to shut down the boiler, one is to use the medicament as the circulating cleaning solution after cutting the pipe and circularly clean each section of the boiler; one is to use a pump truck to push a cleaning ball to clean the pipeline after cutting the pipe. Along with the change of the scale sample, the problems that the reduction effect of the operating differential pressure of the boiler is not obvious, the duration effect time after cleaning is short and the like occur in the conventional cleaning operation, and in addition, a certain safety risk exists in frequent cutting and welding of the boiler tube.

The on-line cleaning solution for the non-stop equipment is provided for solving the outstanding contradiction between stable and continuous operation of production, and the problem that the non-stop equipment is not in operation is solved.

Disclosure of Invention

An object of the utility model is to provide a simple structure, economical and practical utilizes the inside connection structure characteristics of current high pressure steam injection boiler, does not need the blowing out, utilizes the front end to add the medicinal cupping and carries out the water injection and dose, and the medicament is along with the water injection steam flow direction for the scale that each branch part boiler pipe of high pressure steam injection boiler was interior to be tied obtains dissolving, thereby makes the boiler total pressure differential and each section pressure differential of boiler reduce to qualified standard, can effectively improve boiler work efficiency, the online cleaning system who is used for oil field high pressure steam injection boiler who guarantees boiler normal operating.

The utility model discloses an online cleaning system for an oil field high-pressure steam injection boiler, which mainly comprises a chemical feeding tank, a centrifugal pump and a steam injection boiler system device, wherein the steam injection boiler system device mainly comprises a plunger pump, a feed water preheater, a convection section, a superheating section, a radiation section, a sampling separator, a steam-water separator and a steam injection shaft;

the chemical feeding tank is communicated with the plunger pump through a chemical feeding pipeline by a centrifugal pump and is also communicated with a feed water preheater, a convection section, a superheating section and a radiation section by pipelines; the pipeline connections among the feed water preheater, the convection section, the superheating section and the radiation section are connected according to the connection relation of the original high-pressure steam injection boiler, and can be not changed additionally.

The outlet of the radiation section is communicated with a steam-water separation device through a pipeline and a sampling separator, and the outlet of the overheating section is communicated with a steam injection shaft through a pipeline and a water spray desuperheater.

And a dry steam outlet of the steam-water separator is communicated with the overheating section through a pipeline, and a saturated water outlet of the steam-water separator is communicated with the steam injection shaft through a pipeline and a water spray desuperheater.

Preferably, the two medicine adding tanks are connected with the medicine adding pipeline in a parallel mode.

At present, the high-pressure steam injection boiler has high operation pressure difference caused by scaling in a boiler tube in the operation process, the normal operation of the steam injection boiler is influenced, and particularly, the pressure difference of a boiler radiation section is highest, so that the tube bundle of a boiler body is easy to block and explode. The conventional cleaning method adopted at present needs to be shut down, and acid is used as a circulating cleaning solution after a pipe is cut, and each section of the boiler is circularly cleaned; the pressure difference reduction effect of the conventional cleaning is not obvious, and the pressure difference is increased (from 4MPa to 8 MPa) after the conventional cleaning for about 1 month.

The conventional cleaning process needs to be stopped and circularly cleaned, and has a plurality of problems:

(1) the furnace needs to be shut down for 3 to 5 days for one time of cleaning, and normal steam injection production is influenced;

(2) the boiler tube is easy to corrode during acid washing;

(3) the circular cleaning needs to cut the furnace tube for welding, so that the safety risk is increased;

(4) the construction period is long, and the management difficulty is increased.

The utility model discloses the theory of operation:

putting a self-developed descaling cleaning agent into a front-end dosing tank, adding the descaling cleaning agent into the steam-injection boiler system device from an inlet of a plunger pump, cleaning a boiler tube in each section after the descaling cleaning agent passes through a preheater, a convection section and a radiation section, heating and vaporizing water in the radiation section to reach 80% of steam dryness, then separating the water from the steam in a spherical steam-water separation device, discharging the separated dry steam from a dry-steam outlet, then heating the dry steam in a superheating section, feeding a small amount of descaling cleaning agent into the superheating section along with the dry steam to clean and descale the superheating section, feeding the water into a water-spraying desuperheater at the temperature of about 470 ℃, mixing the descaling cleaning agent with saturated water separated from the bottom of the steam-water separator, reducing the mixed temperature to about 370-390 ℃, gathering and mixing the descaling cleaning agent at the bottom of the steam-water separator and mixing the descaling cleaning agent along with the water-spraying desuperheater, mixing the high-concentration cleaning agent in the saturated water into the dry steam, and finally, injecting superheated steam into the underground by using the steam injection shaft. After superheated steam is injected into the steam injection shaft, the mixed part of the descaling cleaning agent can be used for descaling and cleaning the steam injection shaft, so that soft scale on the steam injection shaft can be cleaned, and the steam injection efficiency is improved.

Compared with the prior art, the utility model has the advantages that:

after the high-pressure steam injection boiler is cleaned on line, the total pressure difference of the boiler is obviously reduced, the pressure difference value of each section of the boiler is restored to the normal pressure difference, the total pressure difference value of the boiler after cleaning and descaling on line is less than or equal to 4MPa, the pressure difference value of each section of the boiler is less than or equal to 2.5MPa, (the pressure difference values of the boiler before and after cleaning and descaling on line of the boiler are compared, the water quantity and the dryness in the comparison data are kept consistent), and the scale in the boiler tube is effectively reduced after the boiler is cleaned by the online cleaning and descaling technology, so that the descaling effect is obvious and thorough, the thermal efficiency of the boiler is improved, the energy consumption of the boiler is reduced, the natural gas consumption is saved, and the shutdown time of the boiler caused by the long construction period of conventional cleaning can be reduced.

The online cleaning system for the high-pressure steam injection boiler is operated on the technical field, so that the problem that the steam injection production is influenced by overhigh boiler pressure difference caused by scaling in a boiler tube is solved, the labor intensity of workers is reduced, the unplanned boiler shutdown time rate of the boiler is reduced, the accuracy of steam dryness measurement is ensured, the safety risk of equipment operation is reduced, and the steam injection quality effect is ensured; the steam production of the boiler is increased, the oil well yield is increased, and obvious economic benefits are achieved.

The utility model discloses simple structure, economical and practical utilizes the inside connection structure characteristics of current high pressure steam injection boiler, does not need the blowing out, utilizes the front end to add the medicinal cupping and carries out the water injection and dose, and the medicament is along with the water injection steam flow direction for scale deposit obtains dissolving in each minute part boiler tube of high pressure steam injection boiler, thereby makes the boiler total pressure differential and each section pressure differential of boiler reduce to qualified standard, can effectively guarantee that the boiler improves work efficiency, normal operating.

Drawings

Fig. 1 is a schematic view of a system flow structure according to an embodiment of the present invention.

Shown in the figure: 1 is with medicine jar I, 2 is with medicine jar II, 3 is with the medicine pipeline, 4 is the centrifugal pump, 5 is boiler water supply entry, 6 is the plunger pump, 7 is the feedwater preheater, 8 is the convection section, 9 is the superheating section, 10 is the radiation section, 11 is the catch water, 12 is the dry steam export, 13 is the saturated water export, 14 is blowdown dilatation jar, 15 is the steam injection pit shaft, 16 is the water spray desuperheater, 17 is the sample separator, 18 is the cooling water entry, 19 is the oil heater, 20 is the electric heater, 21 is oil return line, 22 is the air compressor machine, 23 is the natural gas entry, 24 is the combustor.

Detailed Description

Example 1:

referring to the attached drawings, the structure schematic diagram of the embodiment of the utility model is that an online cleaning system for an oil field high pressure steam injection boiler mainly comprises a chemical feeding tank, a centrifugal pump 4 and a steam injection boiler system device, wherein the steam injection boiler system device mainly comprises a plunger pump 6, a feed water preheater 7, a convection section 8, an overheating section 9, a radiation section 10, a sampling separator, a steam-water separator and a steam injection shaft;

the chemical feeding tank is communicated with a plunger pump 6 through a chemical feeding pipeline 3 and a centrifugal pump 4 and is also communicated with a feed water preheater 7, a convection section 8, a superheating section 9 and a radiation section 10 through pipelines; the pipeline connections among the feed water preheater, the convection section, the superheating section and the radiation section are connected according to the connection relation of the original high-pressure steam injection boiler without other changes.

The outlet of the radiation section 10 is communicated with a steam-water separation device 11 through a pipeline and a sampling separator 17, and the outlet of the superheating section 9 is communicated with a steam injection shaft 15 through a pipeline and a water spray desuperheater 16;

and a dry steam outlet 12 of the steam-water separator 11 is communicated with the overheating section 9 through a pipeline, and a saturated water outlet 13 of the steam-water separator 11 is communicated with a steam injection shaft 15 through a pipeline and a water spray desuperheater 16.

The medicine adding tanks are two, namely a medicine adding tank I1 and a medicine adding tank II 2, and are connected with the medicine adding pipeline 3 in a parallel connection mode.

In the embodiment, the total pressure difference of the boiler before cleaning is 6.27MPa, wherein the pressure difference of the radiation section is 3.43 MPa. The boiler normally operates, but because the pressure difference is too high due to scaling in the pipelines, the energy consumption is increased, and the safety risk is increased, the boiler is urgently required to be cleaned and descaled without stopping the boiler.

The field device equipment is equipped with:

(1) 2 medicine adding tanks, effective volume: 1m³×2；

(2) 1 vertical centrifugal dosing pump: head 160m, flow 4m³H, the motor power is 4 kw;

(3) the medicament preparation water source 1, the 380V power supply wiring 1 and a plurality of connecting pipeline valves.

Safe operation rules for online cleaning of boilers:

(1) before cleaning, a field responsible person carries out comprehensive detailed inspection on equipment to be cleaned, knows the equipment and materials so as to determine a cleaning mode and formulate safety measures and check whether water and electricity have cleaning conditions;

(2) before cleaning, a cleaning system is required to be designed, the dosage of a chemical cleaning agent is calculated, and cleaning equipment, materials, safety supplies and other articles are prepared;

(3) in the cleaning process, technical responsible personnel and quality inspectors need to complete data, complete cleaning record and accurate data, and smoke and fire are strictly prohibited in the cleaning process;

(4) strictly executing a cleaning scheme according to a chemical cleaning rule of the boiler, and not changing the scheme randomly;

(5) and a cleaning process: the chemical feeding tank → the cleaning pipeline → the chemical feeding pump → the water inlet pipeline at the front end of the boiler plunger pump;

(6) and the requirement of a cleaning system: a) the medicament tank should have sufficient volume and the dosing pump should be corrosion resistant. b) The cleaning liquid outlet is provided with a filter screen, the aperture of the filter screen is smaller than 5mm, and the effective flow cross section is larger than three times of the inlet cross section. c) The valve in the cleaning system is flexible, tight and corrosion resistant. d) After the cleaning device system is connected, the leakage test is carried out by using clear water of 0.8-1.6mPa, and the liquid can be fed after the cleaning device system is qualified, so as to carry out the chemical cleaning operation.

And (3) cleaning the boiler on line on site, wherein the total pressure difference of the boiler before cleaning is 6.27MPa, and the pressure difference of a radiation section is 3.43 MPa. The cleaning and descaling are carried out without stopping the boiler by adding the chemicals, the total pressure difference of the boiler is reduced to 2.89MPa, the pressure difference of the radiation section is reduced to 1.19MPa, and the cleaning effect is obvious. Taking a single high-pressure steam injection boiler as an example: the high-pressure steam injection boiler needs to be stopped for 3-5 days every time of normal cleaning, the boiler is stopped for at least 3 days according to the normal cleaning, and the oil-steam ratio is calculated as 0.08: and (3) carrying out conventional cleaning once oil yield reduction by 23 m/h 0.9 h 0.08=119.2t on the high-pressure steam injection boiler, and reducing the benefit by 23.8 ten thousand yuan. The cost for cleaning a single boiler is 10 ten thousand yuan. The benefit of a single boiler is as follows: 23.8-10 ten thousand yuan =13.8 ten thousand yuan. The utility model discloses mounting process is convenient, need not stop transport boiler and industrial equipment, and technical indicator satisfies the on-the-spot demand of oil field production, and on-the-spot adaptability is high.

Claims (2)

1. An online cleaning system for a high-pressure steam injection boiler of an oil field is characterized by mainly comprising a dosing tank, a centrifugal pump and a steam injection boiler system device, wherein the steam injection boiler system device mainly comprises a plunger pump, a feed water preheater, a convection section, a superheating section, a radiation section, a sampling separator, a steam-water separator and a steam injection shaft;

the chemical feeding tank is communicated with the plunger pump through a chemical feeding pipeline by a centrifugal pump and is also communicated with a feed water preheater, a convection section, a superheating section and a radiation section by pipelines;

the outlet of the radiation section is communicated with a steam-water separation device through a pipeline and a sampling separator, and the outlet of the overheating section is communicated with a steam injection shaft through a pipeline and a water spray desuperheater;

and a dry steam outlet of the steam-water separator is communicated with the overheating section through a pipeline, and a saturated water outlet of the steam-water separator is communicated with the steam injection shaft through a pipeline and a water spray desuperheater.

2. The on-line cleaning system for the oilfield high pressure steam injection boiler according to claim 1, wherein the number of the dosing tanks is two, and the dosing tanks are connected with the dosing pipeline in parallel.

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