阅读说明：本技术 基于油田伴生气自气浮油水预分离装置及处理方法 (Oil-water pre-separation device based on oilfield associated gas self-air flotation and treatment method ) 是由 戚亚明 黄强 吴昊 王立龙 张斌 樊军 张侃毅 李龙 蒋旭 刁建华 严文强 贾 于 2020-07-06 设计创作，主要内容包括：本发明涉及油井采出液油水分离技术领域,是一种基于油田伴生气自气浮油水预分离装置及处理方法,前者包括罐体,罐体内部由左至右依次分为相互连通的预处理腔、重力沉降分离腔和原油缓冲腔,预处理腔与重力沉降分离腔之间设置有分别使预处理腔与重力沉降分离腔的上部和下部连通的挡板一。本发明充分利用油井采出液中的伴生气作为气浮气源,加速了原油和采出水的分离,再通过布液装置,实现伴生气在液相中的均匀逸出,形成有效的气浮作用,利用该作用实现在不设置外部设施的情况下,减小设备尺寸,降低投资成本,提高了油水分离的效率,达到了预期的分离效果,应用前景广阔、市场潜力大。(The invention relates to the technical field of oil-water separation of oil well produced liquid, in particular to an oil-water pre-separation device and a treatment method based on self-air floatation of oilfield associated gas. The invention fully utilizes the associated gas in the oil well produced liquid as an air flotation gas source, accelerates the separation of crude oil and produced water, realizes the uniform escape of the associated gas in a liquid phase through the liquid distribution device, forms an effective air flotation effect, reduces the size of equipment, reduces the investment cost, improves the oil-water separation efficiency under the condition of not arranging external facilities, achieves the expected separation effect, and has wide application prospect and great market potential.)

1. An oil-water preseparation device based on self-air floatation of oilfield associated gas is characterized by comprising a tank body, wherein the interior of the tank body is sequentially divided into a pretreatment cavity, a gravity settling separation cavity and a crude oil buffer cavity which are communicated with each other from left to right, a baffle I which respectively enables the pretreatment cavity to be communicated with the upper part and the lower part of the gravity settling separation cavity is arranged between the pretreatment cavity and the gravity settling separation cavity, the front side and the rear side of the baffle I are respectively and fixedly installed with the inner wall of the front side and the inner wall of the rear side of the left part of the tank body, a liquid distribution device is fixedly installed at the lower part of the pretreatment cavity, a liquid inlet pipe communicated with the liquid distribution device is arranged on the tank body, a liquid level stabilizing device is arranged in the pretreatment cavity above the liquid distribution device and not exceeding the baffle I, a baffle II which enables the gravity settling separation cavity to be communicated with the upper part of the crude oil buffer cavity is arranged between the gravity, at least one oil-water separation device is arranged in the gravity settling separation cavity, the oil-water separation device is fixedly installed on the inner wall of the top of the tank body, a water collecting pipe is arranged on the lower portion of the gravity settling separation cavity, which is close to the position between the oil-water separation device on the rightmost side and the baffle II, a water outlet pipe communicated with the outer side of the bottom of the tank body is fixedly communicated with the water collecting pipe, an oil outlet is formed in the bottom of the tank body of the crude oil buffer cavity, and an air outlet.

2. The oil-water preseparation device based on the self-air-flotation of the oilfield associated gas as claimed in claim 1, wherein the gravity settling separation chamber above the corresponding water collecting pipe is provided with an emulsion collecting pipe at the middle part, the outer wall of the tank body below the emulsion collecting pipe is provided with an emulsion overflow hole, an emulsion discharge pipe is fixedly communicated between the emulsion overflow hole and the emulsion collecting pipe, and the tank body corresponding to the emulsion collecting pipe is provided with at least two emulsion sampling ports.

3. The oil field associated gas self-air-flotation oil-water pre-separation device based on the claim 1 or 2 is characterized in that the liquid distribution device comprises a liquid distribution main pipe and liquid distribution branch pipes, a sand washing port is formed in the lower portion of the left side of the tank body, the left side of the liquid distribution main pipe is fixedly communicated with the sand washing port, the right side of the liquid distribution main pipe is fixedly installed on a first baffle plate, at least one liquid distribution branch pipe is distributed on the liquid distribution main pipe at intervals in the left and right directions, the front side and the rear side of each liquid distribution branch pipe horizontally penetrate through and are fixed on the liquid distribution main pipe, and liquid outlets are formed in the front side and the rear side.

4. The oil field associated gas self-air-floatation oil-water pre-separation device based on the claim 1 or 2 is characterized in that a liquid level meter is arranged in a crude oil buffer cavity at the bottom of the tank body, and at least one drain outlet is arranged at the bottom of the tank body.

5. The oil field associated gas self-air-floatation oil-water pre-separation device based on the claim 3 is characterized in that a liquid level meter is arranged in a crude oil buffer cavity at the bottom of the tank body, and at least one sewage draining outlet is arranged at the bottom of the tank body.

6. The oilfield associated gas self-floatation oil-water pre-separation device based on the claim 1, 2 or 5, wherein a manual vent, a safety valve interface and at least one manhole are arranged at the top of the tank body.

7. The oilfield associated gas based self-air-floatation oil-water pre-separation device according to claim 3, wherein a manual vent, a safety valve interface and at least one manhole are arranged at the top of the tank body.

8. The oilfield associated gas self-air-floatation oil-water pre-separation device based on the claim 4, wherein a manual vent, a safety valve interface and at least one manhole are arranged at the top of the tank body.

9. The treatment method of the oil field associated gas self-floatation oil-water pre-separation device according to any one of claims 1 to 8, which is characterized in that the separation of tiny oil drops which cannot be separated originally by gravity settling is realized by utilizing the floatation action of associated gas in oil well produced liquid, and the method is carried out according to the following steps: the oilfield produced liquid enters a liquid distribution main pipe of a liquid distribution device from a liquid inlet pipe at the top of a tank body, and enters a pretreatment cavity from a liquid outlet on a liquid distribution branch pipe, associated gas in the produced liquid escapes from the liquid, crude oil with lower density floats upwards to realize pre-separation, when the liquid level exceeds a first baffle plate, the associated gas turns over the first baffle plate to enter a gravity settling separation cavity, further oil-water separation is realized through an oil-water separation device, an oil layer is on the top, a water layer is on the bottom, when the liquid level exceeds a second baffle plate, the crude oil turns over the second baffle plate to enter a crude oil buffer cavity, the crude oil on the upper layer enters the crude oil buffer cavity and is discharged from an oil outlet, the produced water on the lower layer is collected through a water collecting pipe and is discharged through.

Technical Field

The invention relates to the technical field of oil-water separation of oil well produced liquid, in particular to an oil-water pre-separation device and a treatment method based on self-air flotation of oilfield associated gas.

Background

At present, the oil-water separation of oil field produced liquid at home and abroad mainly adopts gravity settling or centrifugation, cyclone separation and other methods, associated gas in the produced liquid is separated before the oil-water separation, the oil-water separation process is carried out in a pure liquid phase chamber, the separation is generally carried out by the gravity settling or the centrifugation and cyclone separation methods, and the oil and water are required to have certain density difference, the gravity settling has the defects of long time, low separation efficiency and large equipment volume, and the centrifugation and cyclone separation have the defects of large influence caused by the change of the liquid volume, so the application is limited to a certain extent.

Disclosure of Invention

The invention provides an oil-water pre-separation device based on self-air flotation of oilfield associated gas and a treatment method, overcomes the defects of the prior art, and can effectively solve the problems of long separation time and low efficiency caused by partial gravity settling separation of the conventional oil-water separation device and the problem of small application range caused by the restriction of the liquid quantity caused by partial centrifugation and cyclone separation.

One of the technical schemes of the invention is realized by the following measures: an oil-water preseparation device based on self-air floatation of oilfield associated gas comprises a tank body, the interior of the tank body is sequentially divided into a pretreatment cavity, a gravity settling separation cavity and a crude oil buffer cavity which are communicated with each other from left to right, a baffle I which respectively enables the pretreatment cavity to be communicated with the upper part and the lower part of the gravity settling separation cavity is arranged between the pretreatment cavity and the gravity settling separation cavity, the front side and the rear side of the baffle I are respectively and fixedly installed with the inner wall of the front side and the inner wall of the rear side of the left part of the tank body, a liquid distribution device which can realize uniform liquid distribution is fixedly installed at the lower part of the pretreatment cavity, a liquid inlet pipe communicated with the liquid distribution device is arranged on the tank body, a liquid level stabilizing device is arranged in the pretreatment cavity above the liquid distribution device and not exceeding the baffle I, a baffle II which enables the gravity settling separation cavity to be communicated with the upper part of the crude oil buffer cavity is arranged between the gravity, at least one oil-water separation device is arranged in the gravity settling separation cavity, the oil-water separation device is fixedly installed on the inner wall of the top of the tank body, a water collecting pipe is arranged on the lower portion of the gravity settling separation cavity, which is close to the position between the oil-water separation device on the rightmost side and the baffle II, a water outlet pipe communicated with the outer side of the bottom of the tank body is fixedly communicated with the water collecting pipe, an oil outlet is formed in the bottom of the tank body of the crude oil buffer cavity, and an air outlet.

The following is a further optimization or/and improvement of one of the above-mentioned technical solutions of the invention:

the middle part of the gravity settling separation cavity corresponding to the upper part of the water collecting pipe is provided with an emulsion collecting pipe, the outer wall of the tank body positioned below the emulsion collecting pipe is provided with an emulsion overflow hole, an emulsion discharge pipe is fixedly communicated between the emulsion overflow hole and the emulsion collecting pipe, and the tank body corresponding to the emulsion collecting pipe is provided with at least two emulsion sampling ports.

The liquid distribution device comprises a liquid distribution main pipe and liquid distribution branch pipes, a sand flushing port is formed in the lower portion of the left side of the tank body, the liquid distribution device is regularly flushed through the sand flushing port, a liquid outlet of the liquid distribution device is prevented from being blocked by silt, the left side of the liquid distribution main pipe and the sand flushing port are fixedly communicated, the right side of the liquid distribution main pipe is fixedly installed on a baffle plate, the liquid distribution main pipe is provided with at least one liquid distribution branch pipe in a left-right interval distribution mode, each liquid distribution branch pipe is front and rear horizontal penetrating and fixing the liquid distribution main pipe, and the front side and the rear side of each liquid distribution branch pipe are provided with liquid outlets.

The crude oil buffer cavity at the bottom of the tank body is internally provided with a liquid level meter, and the bottom of the tank body is provided with at least one drain outlet.

The top of the tank body is provided with a manual vent, a safety valve interface and at least one manhole.

The water collecting pipe and the emulsion collecting pipe are fixedly arranged at the bottom of the tank body through a supporting rod.

The second technical scheme of the invention is realized by the following measures: a treatment method based on an oil field associated gas self-floatation oil-water pre-separation device is characterized in that the separation of original micro oil drops which cannot be separated by gravity settling is realized by utilizing the air floatation action of associated gas in oil well produced liquid, and the treatment method is carried out according to the following method: the oilfield produced liquid enters a liquid distribution main pipe of a liquid distribution device from a liquid inlet pipe at the top of a tank body, and enters a pretreatment cavity from a liquid outlet on a liquid distribution branch pipe, associated gas in the produced liquid escapes from the liquid, crude oil with lower density floats upwards to realize pre-separation, when the liquid level exceeds a first baffle plate, the associated gas turns over the first baffle plate to enter a gravity settling separation cavity, further oil-water separation is realized through an oil-water separation device, an oil layer is on the top, a water layer is on the bottom, when the liquid level exceeds a second baffle plate, the crude oil turns over the second baffle plate to enter a crude oil buffer cavity, the crude oil on the upper layer enters the crude oil buffer cavity and is discharged from an oil outlet, the produced water on the lower layer is collected through a water collecting pipe and is discharged through.

The invention fully utilizes the associated gas in the oil well produced liquid as an air flotation gas source, accelerates the separation of crude oil and produced water, realizes the uniform escape of the associated gas in a liquid phase through the liquid distribution device, forms an effective air flotation effect, reduces the size of equipment, reduces the investment cost, improves the oil-water separation efficiency under the condition of not arranging external facilities, achieves the expected separation effect, and has wide application prospect and great market potential.

Drawings

Fig. 1 is a front perspective structural schematic diagram of embodiment 1 of the present invention.

Fig. 2 is a schematic top view of the liquid distribution device in fig. 1.

The codes in the figures are respectively: 1 is the preliminary treatment chamber, 2 is the gravity settling separation chamber, 3 is crude oil buffer chamber, 4 is the sand washing mouth, 5 is the oil-out, 6 is the liquid distribution person in charge, 7 is the branch pipe of liquid distribution, 8 is the through-hole, 9 is the feed liquor pipe, 10 is baffle one, 11 is the liquid outlet, 12 is the liquid level stabilising arrangement, 13 is baffle two, 14 is oil water separator, 15 is the collector pipe, 16 is the gas outlet, 17 is the outlet pipe, 18 is the emulsion collecting pipe, 19 is the emulsion overflow, 20 is the emulsion discharge pipe, 21 is the emulsion sample connection, 22 is the bracing piece, 23 is the manhole, 24 is the level gauge, 25 is the drain, 26 is manual drain, 27 is the relief valve interface.

Detailed Description

The present invention is not limited by the following examples, and specific embodiments may be determined according to the technical solutions and practical situations of the present invention. The various chemical reagents and chemical articles mentioned in the invention are all the chemical reagents and chemical articles which are well known and commonly used in the prior art, unless otherwise specified; the percentages in the invention are mass percentages unless otherwise specified; the solution in the present invention is an aqueous solution in which the solvent is water, for example, a hydrochloric acid solution is an aqueous hydrochloric acid solution, unless otherwise specified; the normal temperature and room temperature in the present invention generally mean a temperature of 15 ℃ to 25 ℃, and are generally defined as 25 ℃.

The invention is further described below with reference to the following examples: