CN107673430B

CN107673430B - Treatment device for produced water of oil and gas field

Info

Publication number: CN107673430B
Application number: CN201610624606.1A
Authority: CN
Inventors: 唐志伟; 党伟; 黄辉; 徐孝轩; 谭文捷; 王莉莉; 胡长朝; 毕彩霞
Original assignee: China Petroleum and Chemical Corp; Sinopec Exploration and Production Research Institute
Current assignee: China Petroleum and Chemical Corp; Sinopec Exploration and Production Research Institute
Priority date: 2016-08-02
Filing date: 2016-08-02
Publication date: 2021-05-14
Anticipated expiration: 2036-08-02
Also published as: CN107673430A

Abstract

The invention relates to a treatment device for oil and gas field produced water, which comprises: an evaporation chamber, and a liquid supply channel extending into the evaporation chamber, the liquid supply channel configured to supply liquid into the evaporation chamber. The device for treating the oil and gas field produced water can reduce the amount of salt-containing sewage generated by the oil and gas field produced water.

Description

Treatment device for produced water of oil and gas field

Technical Field

The invention relates to treatment of produced water of an oil and gas field, in particular to a treatment device for the produced water of the oil and gas field.

Background

Oil and gas field produced water is mainly water in a stratum structure, and is brought to the surface along with crude oil and natural gas in the oil and gas production process. The water quality of the produced water of the oil and gas field is very complex, and mainly comprises water, oil, suspended matters, scale forming components such as calcium, magnesium and the like existing in the produced water in an ion form, bacteria, various agents (such as foaming agents) added in the oil production process, a large amount of chloride ions and the like.

In the prior art, membrane filtration technology is commonly used to treat oil and gas field produced water. However, it is difficult to separate out the salt ions dissolved in the water by this treatment, and the cost of this treatment is very high. Along with the exploitation of petroleum in China, an increasing amount of oil and gas field produced water is produced, and therefore an increasing amount of salt-containing sewage is produced. These salts cause the produced water of the oil and gas field to exceed the standard of sewage discharge. How to dispose of such large volumes of field produced water remains a challenge to those skilled in the art.

Therefore, there is a need for an apparatus that reduces the amount of saline wastewater produced from oil and gas field produced water.

Disclosure of Invention

In view of the above problems, the present invention provides a treatment device for oil and gas field produced water, which can reduce the amount of saline sewage generated by the oil and gas field produced water.

The invention provides a treatment device for produced water of an oil and gas field, which comprises: an evaporation chamber, and a liquid supply channel extending into the evaporation chamber, the liquid supply channel configured to supply liquid into the evaporation chamber.

Through the treatment device for the oil and gas field produced water, provided by the invention, liquid (such as oil and gas field produced water or oil and gas field produced water after certain treatment) can be introduced into the evaporation chamber. In the evaporating chamber, the water in the produced water of the oil and gas field is evaporated, so that the amount of salt-containing sewage generated by the produced water of the oil and gas field can be reduced. Through this kind of processing apparatus, can reduce the volume of sewage effectively to the operation personnel of having made things convenient for from this to handle sewage.

In one embodiment, a mist outlet mechanism is configured on a part of the liquid supply channel extending into the evaporation chamber, and the liquid in the liquid supply channel can enter the evaporation chamber in a mist-like form under the action of the mist outlet mechanism. By this arrangement, the contact area of the liquid with the auxiliary gas in the evaporation chamber is increased, thereby promoting evaporation of moisture in the liquid.

In one embodiment, the mist generating mechanism comprises a spray head communicated with the liquid supply channel, and a gas supply channel communicated with the spray head, wherein the gas supply channel can supply auxiliary gas into the spray head, and the liquid is sprayed into the evaporation chamber in a mist-like form under the action of the auxiliary gas. By this arrangement, the contact of the liquid with the assist gas is further promoted, and the moving speed of the liquid and the gas is increased, whereby the evaporation of the moisture in the liquid is further promoted.

In one embodiment, the communication of the liquid supply channel with the showerhead is between the liquid outlet of the showerhead and the communication of the gas supply channel with the showerhead. Thereby, the assist gas is brought into contact with the liquid more sufficiently, and evaporation of the moisture is promoted.

In one embodiment, the spray head is at the bottom of the evaporation chamber and the liquid outlet is configured to face upward, preferably vertically upward. By this arrangement the time for the liquid to come into contact with the secondary gas in the evaporation chamber is extended and a flow path is created in the evaporation chamber which is more favourable for evaporation of the moisture.

In one embodiment, the showerhead is configured such that its internal cavity gradually increases in a direction from its communication with the gas supply passage to the liquid outlet. This arrangement further facilitates contact of the secondary gas with the liquid and thereby facilitates droplet formation by the liquid.

In one embodiment, the evaporation chamber is configured with a gas outlet at a top thereof, and a gas filtering member is provided at the gas outlet of the evaporation chamber, the gas filtering member comprising: a filter housing, a gas inlet opening being formed in a side wall of the filter housing facing the interior of the evaporation chamber, a concentrated substance outlet opening being formed in a bottom wall of the filter housing facing the interior of the evaporation chamber, a gas outlet opening being provided in a wall of the filter housing facing away from the interior of the evaporation chamber, the gas outlet opening being connected to the outside of the evaporation chamber, wherein a flap is formed in the filter housing between the gas inlet opening and the gas outlet opening, the flap extending so as to form a meandering flow path between the gas inlet opening and the gas outlet opening. By means of such a gas filter member, the concentrate which would have left the evaporation chamber with the evaporated gas through the gas outlet of the evaporation chamber can be blocked off, so that only or substantially only water vapour can enter the environment through the gas outlet of the evaporation chamber.

In one embodiment, one end of a flap is connected to the filter housing and the other end of the flap is spaced from the filter housing to form an opening for passage of fluid within the filter housing, wherein the flap is a plurality of flaps parallel to and spaced apart from each other, the plurality of flaps extending in a horizontal direction to form a barrier between the filtered gas inlet and the filter body outlet, and one end of adjacent flaps connected to the filter housing and the other end spaced apart from the filter housing are on opposite sides of the filter housing. With this arrangement, a serpentine flow path is formed within the filter housing. The gas can smoothly pass through the flow channel, and liquid drops and/or particles can be blocked at the turning part due to inertia. This configuration maximizes the number of droplets and/or particles that are retained.

In one embodiment, the bottom of the evaporation chamber is configured such that its inner cavity tapers in a vertically downward direction. The structure is more beneficial to collecting the evaporated concentrated substance. The concentrated material that comes together is difficult to re-entrain by the gas stream.

In one embodiment, a pre-treatment assembly is connected to an upstream portion of the liquid supply channel supplying liquid into the evaporation chamber, the pre-treatment assembly being configured to separate evaporation-impeding substances in the field produced water from the field produced water, wherein the separated liquid is fed into the evaporation chamber through the liquid supply channel. The arrangement is favorable for the smooth proceeding of the evaporation process in the evaporation chamber, and the evaporation efficiency can be effectively ensured.

Compared with the prior art, the invention has the advantages that: a liquid (e.g., field produced water or field produced water after some treatment) can be passed into the evaporation chamber. In the evaporating chamber, the water in the produced water of the oil and gas field is evaporated, so that the amount of salt-containing sewage generated by the produced water of the oil and gas field can be reduced. Through this kind of processing apparatus, can reduce the volume of sewage effectively to the operation personnel of having made things convenient for from this to handle sewage.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

fig. 1 shows a schematic structural view of one embodiment of the treatment device for oil and gas field produced water of the present invention.

Fig. 2 shows a schematic view of the gas filtering member of the treatment device for oil and gas field produced water of fig. 1.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

Fig. 1 schematically shows the structure of a treatment apparatus for oil and gas field produced water (hereinafter simply referred to as "treatment apparatus") 100 according to the present invention.

The processing apparatus 100 includes an evaporation chamber 1, and a liquid supply channel 2 extending into the evaporation chamber 1. The liquid supply channel is configured to pass a liquid therethrough and supply the liquid into the evaporation chamber 1. The water contained in the liquid will evaporate from the liquid in the evaporation chamber 1, whereby the amount of liquid can be reduced.

It should be understood that, in the case of using the processing apparatus 100 to process the oil and gas field produced water, the oil and gas field produced water may be directly supplied into the evaporation chamber 1 through the liquid supply channel 2, or the oil and gas field produced water may be first subjected to a certain processing and then supplied into the evaporation chamber 1 through the liquid supply channel 2. For convenience of description, the oil and gas field produced water fed into the evaporation chamber 1 and the treated oil and gas field produced water will be collectively referred to as "liquid" herein. However, it should be understood that it is also possible for the field produced water to contain other substances in gaseous or solid form.

Some of the treatment of oil and gas field produced water described above may be achieved by connecting a pre-treatment assembly 6 to the liquid supply channel 2. Through the pretreatment module 6, oil, suspended matters, foaming components and the like in the produced water of the oil and gas field can be prevented from being removed. The produced water of the oil and gas field only contains or mainly contains salt and water after being treated by the method. Feeding such contaminated water containing only or mainly salt and water to the evaporation chamber 1 through the liquid supply channel 2 is more advantageous for evaporation to proceed, thereby enabling the efficiency of evaporation to be improved. In addition, the pretreatment by the pretreatment module 6 prevents the clogging of the liquid supply passage 2 with components such as oil, suspended matter, etc. For example, the oil content in the produced water can be reduced to below 10mg/L, and suspended matter in the produced water with particle size of over 30 microns can be removed.

Preferably, a mist outlet mechanism is provided on the liquid supply channel, which is configured such that the liquid can be converted into a mist/droplet-like form therein and enter the evaporation chamber 1 in the mist/droplet-like form. By making the liquid in the form of droplets, the contact area of the liquid with the auxiliary gas (e.g., air) within the evaporation chamber can be increased, thereby increasing the efficiency of evaporation.

As shown in fig. 1, the mist discharge mechanism may include a showerhead 3 and a gas supply passage 4 communicating with the showerhead 3, the gas supply passage 4 supplying an auxiliary gas into the showerhead 3. An air pump 41 may be provided on the gas supply path 4 to ensure smooth entry of the assist gas into the gas supply path 4. The head 3 is also in communication with the liquid supply passage 2. The assist gas and the liquid are mixed in the shower head 3 and then sprayed together into the evaporation chamber 1. Therefore, the moving speed of the liquid in the evaporation chamber 1 is increased, and the particle size of the mist formed by the liquid is smaller, so that the evaporation efficiency of the moisture in the liquid is further improved.

Preferably, as shown in fig. 1, the communication of the liquid supply passage 2 with the showerhead 3 is between the liquid outlet 31 of the showerhead 3 and the communication of the gas supply passage 4 with the showerhead 3. By this arrangement, the liquid and the assist gas can be more sufficiently mixed in the head 3, thereby contributing more to making the mist of the liquid smaller.

In addition, it is also possible to have the spray head 3 at the bottom of the evaporation chamber 1, as shown in fig. 1, with the liquid outlet 31 facing upwards, preferably vertically upwards. In this way, the liquid can be in contact with the secondary gas for a longer time inside the evaporation chamber 1 and a flow path can be formed inside the evaporation chamber 1 substantially as shown by the scissor in fig. 1. This arrangement can further improve the efficiency of evaporation of moisture in the liquid.

Preferably, the showerhead 3 is constructed such that its inner cavity gradually increases in the direction from its communication with the gas supply passage 4 to the liquid outlet 31. That is, in this direction (from the bottom to the top in the figure), the inner chamber of the spray head 3 is substantially conical. By this arrangement, a more advantageous space is provided inside the spray head 3 for the mixing of the liquid with the auxiliary gas, and thus the mist droplets exiting the spray head 3 are more dispersed and have a smaller particle size.

Further, in order to accelerate the evaporation, a heater may be provided in the evaporation chamber 1. The heater is preferably provided at the bottom of the evaporation chamber 1, whereby the flow in the evaporation chamber 1 can be more advantageously promoted.

It is also possible to configure a gas outlet at the top of the evaporation chamber 1 to allow the vapour formed after the partial evaporation of the water to leave the evaporation chamber 1. The gas outlet may be directly connected to the environment, since the steam has no negative influence on the environment. However, it is inevitable that some concentrated material (i.e. material that has not been evaporated, e.g. containing salt and small amounts of water) is entrained in the steam. In order to prevent these concentrates from entering the environment and contaminating the environment, a gas filter member 5 may be provided at the gas outlet.

Fig. 2 schematically shows a top view of the gas filter member 5. The gas filter member 5 comprises a filter housing 5, on which filter housing 5 a gas inlet, a concentrate outlet and a gas outlet are configured. Wherein, the gas inlet is communicated with the evaporation chamber 1, for example, can be arranged on the side wall facing the inside of the evaporation chamber 1; the concentrate outlet also communicates with the evaporation chamber 1, for example being provided on the bottom wall facing the inside of the evaporation chamber 1; the gas outlet is in communication with the external environment, for example may be provided on one or more of the bottom, side or top walls facing away from the interior of the evaporation chamber 1. In addition, a plurality of turning plates are provided inside the filter housing 5 to form a meandering flow passage inside the filter housing 5. The concentrate is difficult to pass smoothly through the serpentine flow path entrained in the gas stream, it impacts the internal walls of the breakover plate or filter housing under inertia and separates from the gas stream of steam. In this way, only steam can be ensured through the gas outlet into the environment.

For convenience of explanation, the turning

plates

521, 522, and 523 will be described as an example to illustrate the formation of the meandering flow channel.

The turning

plates

521, 522, 523 are disposed substantially parallel to each other inside the filter housing 51 and form a barrier between the gas inlet and the gas outlet to prevent gas from being able to flow in a straight direction from the gas inlet to the gas outlet. Wherein one end of the turning

plates

521, 522, 523 is connected to the inner wall of the filter housing 51 and the other end is spaced apart from the filter housing 51 to form an opening therebetween in a horizontal direction. In addition, the connection between the

adjacent turning plates

521 and 522 and the connection between the turning

plates

522 and 523 are required to be maintained such that the "one end" and the "the other end" are respectively connected to the inner walls of the filter housing 51 in different directions. For example, one end of the turning

plates

521 and 523 is connected to one side inner wall of the filter housing 51, and the other end forms an opening with the other side inner wall of the filter housing 51; and one end of the breakover plate 522 is connected to the other inner wall of the filter housing 51; the other end forms an opening with one side inner wall of the filter housing 51. A meandering flow path can be formed inside the filter housing 51 through the opening formed between the turning

plates

521, 522, 523 and the filter housing 51.

In one embodiment, the bottom of the evaporation chamber is configured such that its inner cavity tapers in a vertically downward direction. The structure is more beneficial to collecting the evaporated concentrated substance. The concentrated material that comes together is difficult to re-entrain by the gas stream. In addition, a concentrate channel 7 may be connected at the lowermost end of the bottom to discharge the collected concentrate out of the evaporation chamber.

The amount of salt-containing sewage generated by the produced water of the oil and gas field can be effectively reduced by the treatment device 100. Also, the auxiliary gas employed by the treatment device 100 to evaporate the produced water may be air directly from the environment. Therefore, the processing device 100 does not consume excessive energy to evaporate, and the evaporation cost is low.

The test is carried out by taking the produced water of a certain oil and gas field as an example. The produced water of the oil and gas field comprises 6 multiplied by 10⁴mg/L salt, 50mg/L oil and 80mg/L suspension.

The produced water is treated by the treatment device 100 of the present invention. The oil content is reduced to below 10mg/L by the pretreatment component 6, and suspended matters with the particle size of more than 30 microns are separated. The treated produced water is then atomized into droplets having a particle size in the range of 50 to 100 microns and passed into the evaporation chamber 1 for evaporation. In the case where the secondary gas is ambient air, at least 70% of the water is evaporated. If more water is to be evaporated, the evaporated concentrate can be introduced into the evaporation chamber 1 again via the liquid supply channel 2. And the cost of treating the produced water using the treatment device 100 is only about 10 yuan/m³。

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A treatment device for oil and gas field produced water, comprising:

an evaporation chamber, and

a liquid supply channel extending into the evaporation chamber, the liquid supply channel configured to supply liquid into the evaporation chamber;

a mist outlet mechanism is configured on the part of the liquid supply channel extending into the evaporation chamber, and the liquid in the liquid supply channel can enter the evaporation chamber in a mist-shaped form under the action of the mist outlet mechanism;

the mist outlet mechanism comprises a spray head communicated with the liquid supply channel and a gas supply channel communicated with the spray head, the gas supply channel can supply auxiliary gas into the spray head, and the liquid is sprayed into the evaporation chamber in a mist-shaped manner under the action of the auxiliary gas;

the communication position of the liquid supply channel and the spray head is positioned between the liquid outlet of the spray head and the communication position of the gas supply channel and the spray head;

the bottom of the evaporation chamber is constructed to gradually reduce the inner cavity of the evaporation chamber along the vertical downward direction;

a pre-treatment assembly is connected to an upstream portion of the liquid supply channel supplying liquid into the evaporation chamber, the pre-treatment assembly being configured to separate evaporation-impeding substances in the field produced water from the field produced water, wherein the separated liquid is fed into the evaporation chamber through the liquid supply channel;

and a heater is arranged in the evaporation chamber and is arranged at the bottom of the evaporation chamber.

2. The processing apparatus according to claim 1, wherein the spray head is at a bottom of the evaporation chamber and the liquid outlet is configured to face upward.

3. The processing apparatus according to claim 1 or 2, wherein the shower head is configured such that an inner cavity thereof gradually increases in a direction from a communication thereof with the gas supply passage to the liquid outlet.

4. The processing apparatus according to claim 1 or 2, wherein the evaporation chamber is configured with a gas outlet at a top thereof, and a gas filtering member is provided at the gas outlet of the evaporation chamber, the gas filtering member comprising:

a filter housing, a gas inlet being formed on a side wall of the filter housing facing the inside of the evaporation chamber, a concentrated substance outlet being formed on a bottom wall of the filter housing facing the inside of the evaporation chamber, a gas outlet being formed on a wall of the filter housing facing away from the inside of the evaporation chamber, the gas outlet being communicated to the outside of the evaporation chamber,

wherein a flap is configured in the filter housing between the gas inlet and the gas outlet, which flap extends to form a meandering flow path between the gas inlet and the gas outlet.

5. The processing apparatus according to claim 4 wherein one end of the flap is connected to the filter housing and the other end of the flap is spaced from the filter housing to form an opening in the filter housing for passage of fluid therethrough,

wherein the flap plates are plural in parallel and spaced apart from each other, the plural flap plates extend in a horizontal direction to form a shield between the filtered gas inlet and the filtered gas outlet, and the other ends of the adjacent flap plates spaced apart from the filter housing are on opposite sides of the filter housing.