CN207920596U - Deep-sea oil gas water separation device - Google Patents

Abstract

The utility model discloses a deep-sea oil-gas-water separation device, which comprises a gas-liquid separator, an oil-water separator and a buffer tank. There are several connected vertical branch pipes between the gas collecting pipe and the liquid collecting pipe, and the gas phase outlet of the gas collecting pipe is connected with the buffer tank; the oil-water inlet of the oil-water separator is connected with the oil-water separation section through a reducing pipe, The oil-water outlet at the end of the oil-water separation section is connected to the inlet of the buffer tank; the tail of the buffer tank is provided with a gas phase inlet pipe, and an oil chamber is arranged below the gas phase inlet pipe, and the bottom of the oil chamber is connected with the oil-gas outlet pipe; the oil-gas outlet A water outlet pipe is arranged on the side wall of the tank body on one side of the pipe, and the tail end of the water outlet pipe is connected with the water reinjection system of the next stage. The utility model has a simple structure and does not contain movable components inside, which not only reduces the probability of equipment failure, but also can be used in the production of deep-water oil and gas fields for a long time, thereby saving maintenance costs.

Description

Deep sea oil, gas and water separation device

technical field

The utility model relates to the technical field of deep sea oil and gas field development, in particular to a deep sea oil, gas and water separation device.

Background technique

The oil and gas field development scheme based on the underwater separation system has become one of the important models for the development of deep water oil and gas fields. Through the subsea gas-liquid separation, the gas is naturally lifted, and the liquid is pressurized and transported by the electric submersible pump, which can reduce the back pressure of the wellhead, increase the recovery rate, accelerate the production of the oil field, and effectively avoid the formation of hydrates; through the subsea oil, gas and water separation And produced water reinjection, effectively replenish formation pressure, improve recovery rate, enable the development of deep water and low reservoir pressure oilfields, and provide strong support for the flow guarantee of the underwater production system.

At present, the crude oil treatment process of conventional produced fluid commonly used in oilfield production is the process of "free water separator + thermochemical separator + electric dehydrator". In the free water separator, the density difference between oil, gas and water is used to carry out natural gravity sedimentation separation, and the separated crude oil emulsion enters the thermochemical separator for secondary thermochemical demulsification and sedimentation, dehydration below 30%, and then enters In the electric dehydrator, the high-voltage electric field is used to further demulsify the crude oil, so that the water in the crude oil is further separated. This treatment process has problems such as a large amount of demulsifier used, low treatment efficiency, many equipment stages, and high energy consumption. Especially for offshore oil fields with high space requirements, the problems of low treatment efficiency and large floor area are even more serious. Prominent, it is bound to greatly increase the development cost of the oil field.

In recent years, my country's shallow water oil and gas exploration and development technology has made breakthroughs, but the development technology of deep water oil and gas fields is still relatively weak, especially the technology related to the underwater separation system for the development of deep water oil and gas fields. Therefore, it is very timely and necessary to develop an efficient and compact deep-sea oil-gas-water separation system for the economic development of my country's future deep-water oil and gas fields.

Utility model content

The purpose of this utility model is to provide a deep-sea oil-gas-water separation device, which can separate oil, gas and water from the wellhead production fluid in the deep sea high external pressure environment, remove the production water, thereby reducing the back pressure of the wellhead, increasing the recovery rate, reducing Water treatment loads for small offshore production platforms.

In order to achieve the above object, the technical scheme adopted by the utility model is:

A deep-sea oil-gas-water separation device, which includes a gas-liquid separator, an oil-water separator and a buffer tank, the gas-liquid separator includes a gas-liquid inlet, a liquid collection pipe and a liquid phase outlet connected in sequence, and the top of the liquid collection pipe is arranged There is an air collecting pipe whose tail is inclined upwards. The inlet end of the liquid collecting pipe is connected with the inlet end of the air collecting pipe. Several vertical branch pipes are arranged between the air collecting pipe and the liquid collecting pipe. The gas phase outlet at the tail of the gas collection pipe is connected to the gas phase inlet pipe at the tail of the horizontally placed buffer tank through a pipe; the oil-water separator includes an oil-water inlet and an oil-water separation section with a larger pipe diameter, and the oil-water inlet is separated from oil and water through a variable diameter pipe The front end of the oil-water separation section is connected to each other, and the oil-water separation section is a back-shaped elbow with one side of the straight pipe section disconnected. The oil-water outlet at the end of the oil-water separation section is connected with the inlet end of the buffer tank; The gas phase inlet pipe is provided with an oil chamber below the gas phase inlet pipe. The bottom of the oil chamber is connected to the oil and gas outlet pipe that runs through the side wall of the tank. The oil and gas outlet pipe is connected to the water production facilities through pipelines; A water outlet pipe is arranged on the side wall of the tank body, and the tail end of the water outlet pipe is connected with the water reinjection system of the next stage.

Preferably, the liquid collecting pipe is inclined downward, and the position of the outlet of the liquid phase is lower than that of the inlet end.

Preferably, the length of the straight pipe section of the oil-water separation section is much longer than the length of the liquid collecting pipe.

Preferably, the top of the oil chamber is provided with a bell mouth, and the top of the bell mouth is located above the oil-water interface in the buffer tank.

When the utility model is in use, the mined oil-gas-water mixture enters through the gas-liquid inlet, forming a stratified flow of the gas phase and the liquid phase in the liquid collecting pipe, and the gas phase enters the gas collecting pipe from the vertical branch pipe, and the liquid droplets carried by the gas phase flow between the vertical branch pipe and the collecting pipe. Coalesce in the air pipe, settle, and return to the liquid collection pipe through the vertical branch pipe. The separated gas phase enters the buffer tank through the connected gas phase outlet and gas phase inlet pipe, and the separated liquid phase and a small amount of gas phase pass through the interconnected liquid phase outlet and oil-water inlet. Separation of oil, gas and water. The separated oil, gas and water enter the buffer tank through the oil and water outlet, and in the tank of the buffer tank, the oil, gas and water are naturally stratified due to the difference in density. The water in the bottom layer is discharged from the water outlet pipe, and the flow in the water outlet pipe is controlled by adjusting the speed of the downstream reinjection water pump, thereby controlling the oil-water boundary in the buffer tank; when the oil phase in the middle layer reaches the height of the oil chamber, the oil phase It enters the oil chamber over the edge of the bell mouth, and mixes with the gas phase entering the top layer of the buffer tank and the gas phase inlet pipe, and is discharged out of the buffer tank through the oil and gas outlet pipe, and is transported to the water production facility through the pipeline for processing.

The beneficial effects of the utility model are:

(1) The gas-liquid separator in this utility model adopts a composite T-shaped pipe structure, and the oil-water separator adopts a back-shaped pipe structure, which effectively reduces the diameter of the separation device, greatly improves the pressure bearing capacity of the entire separation device, and can adapt to High external pressure environment in the deep sea;

(2) The utility model separates the oil-gas-water mixture at the deep-sea wellhead, and the separated oil and gas are mixed again and then transported to the above-water production facilities through pipelines, and the separated water enters the next-level water reinjection system, reducing the number of offshore production platforms. The water treatment load can maintain the reservoir pressure, so that the oil and gas fields with high water cut and low reservoir pressure can be exploited;

(3) The utility model has a simple structure and does not contain movable components inside, which not only reduces the probability of equipment failure, but also can be used in the production of deep-water oil and gas fields for a long time, thereby saving maintenance costs.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the structural representation of gas-liquid separator among Fig. 1;

Fig. 3 is the structural representation of oil-water separator among Fig. 1;

Fig. 4 is a schematic diagram of the internal structure of the buffer tank in Fig. 1;

Among the figure: 1, gas-liquid separator, 101, gas-liquid inlet, 102, liquid collecting pipe, 103, gas collecting pipe, 104, vertical branch pipe, 105, gas phase outlet, 106, liquid phase outlet, 2, oil-water separator, 201 , oil-water inlet, 202, reducing pipe, 203, oil-water separation section, 204, oil-water outlet, 3, buffer tank, 4, oil chamber, 5, oil and gas outlet pipe, 6, water outlet pipe, 7, gas phase inlet pipe.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

A deep-sea oil-gas-water separation device as shown in Figures 1 to 4, it includes a gas-liquid separator 1, an oil-water separator 2, and a buffer tank 3, and the gas-liquid separator 1 includes a gas-liquid inlet 101 connected in sequence, a liquid collection The pipe 102 and the liquid phase outlet 106, the liquid collection pipe 102 is inclined downward, and the position of the liquid phase outlet 106 is lower than the position of its inlet end. The top of the liquid collecting pipe 102 is provided with a gas collecting pipe 103 whose tail is inclined upward, the inlet end of the liquid collecting pipe 102 is connected with the inlet end of the gas collecting pipe 103, and several vertical branch pipes 104 are arranged between the gas collecting pipe 103 and the liquid collecting pipe 102. The two ends of the vertical branch pipe 104 communicate with the gas collector 103 and the liquid collector 102 respectively, and the gas phase outlet 105 at the tail of the gas collector 103 communicates with the gas phase inlet pipe 7 at the rear of the buffer tank 3 placed horizontally through a pipeline; the oil-water separator 2 includes The oil-water inlet 201 and the oil-water separation section 203 with a larger pipe diameter, the oil-water inlet 201 is connected to the front end of the oil-water separation section 203 through the reducing pipe 202, the oil-water separation section 203 is a back-shaped elbow with one straight pipe section disconnected, and the oil-water separation The length of the straight pipe section of section 203 is much longer than the length of liquid collecting pipe 102 . The oil-water outlet 204 at the tail end of the oil-water separation section 203 communicates with the inlet end of the buffer tank 3; the tail top of the buffer tank 3 is provided with a gas phase inlet pipe 7 that runs through the side wall of the tank body, and an oil chamber 4 is arranged below the gas phase inlet pipe 7. The bottom of the oil chamber 4 is connected to the oil and gas outlet pipe 5 that runs through the side wall of the tank body, and the oil and gas outlet pipe 5 is connected to the water production facility through pipelines; the side wall of the tank body on the side of the oil and gas outlet pipe 5 is provided with a water outlet pipe 6. The tail end of the water outlet pipe 6 is connected to the water reinjection system of the next stage.

When the utility model is in use, the mined oil-gas-water mixture enters through the gas-liquid inlet 101, forming a stratified flow of the gas phase and the liquid phase in the liquid collection pipe 102, and the gas phase enters the gas collection pipe 103 from the vertical branch pipe 104, and the liquid droplets carried by the gas phase Coalesce and settle in the vertical branch pipe 104 and the gas collecting pipe 103, and flow back into the liquid collecting pipe 102 through the vertical branch pipe 104. The separated gas phase enters the buffer tank 3 through the connected gas phase outlet 105 and the gas phase inlet pipe 7, and the separated liquid phase and a small amount of gas phase pass through the interconnected liquid phase outlet 106 and the oil-water inlet 201, and are decelerated through the reducing pipe 202. Afterwards, oil, gas and water are separated in the oil-water separation section 203. The separated oil, gas and water enter the buffer tank 3 through the oil and water outlet 204, and in the tank body of the buffer tank 3, the oil, gas and water are naturally stratified due to the difference in density. The water in the bottom layer is discharged from the water outlet pipe 6, and the flow in the water outlet pipe 6 is controlled by adjusting the speed of the downstream refilling water pump, thereby controlling the oil-water boundary in the buffer tank 3; the oil phase in the middle layer reaches the oil chamber 4 At high altitude, the oil phase crosses the edge of the bell mouth and enters the oil chamber 4, and mixes with the gas phase entering the top layer of the buffer tank and the gas phase inlet pipe, and is discharged from the buffer tank through the oil and gas outlet pipe 5, and is transported to the water production facility for processing through the pipeline deal with.

In the utility model, the gas-liquid separator 1 adopts a compound T-shaped pipe structure, and the oil-water separator 2 adopts a back-shaped pipe structure, which effectively reduces the diameter of the separation device, greatly improves the pressure bearing capacity of the entire separation device, and can adapt to deep sea high external pressure environment. The utility model has a simple structure and does not contain movable components inside, which not only reduces the probability of equipment failure, but also can be used in the production of deep-water oil and gas fields for a long time, thereby saving maintenance costs.

Claims (4)

1. a kind of deep-sea oil gas water separation device, it includes gas-liquid separator（1）, oil water separator（2）And surge tank（3）, It is characterized in that：The gas-liquid separator（1）Including the gas-liquid entrance being sequentially communicated（101）, collector tube（102）And liquid-phase outlet （106）, collector tube（102）Top be equipped with the acclivitous gas collecting tube in tail portion（103）, collector tube（102）Arrival end and collection Tracheae（103）Arrival end be connected, gas collecting tube（103）With collector tube（102）Between be equipped with several vertical branch（104）, hang down Allotment pipe（104）Both ends respectively with gas collecting tube（103）And collector tube（102）It is connected, gas collecting tube（103）The gas phase of tail portion goes out Mouthful（105）Pass through pipeline and horizontal positioned surge tank（3）The gas phase inlet tube of tail portion（7）It is connected；Oil water separator（2）Packet Include grease entrance（201）The water-oil separating section to become larger with caliber（203）, grease entrance（201）Pass through reducer pipe（202）With grease Segregation section（203）Front end is connected, water-oil separating section（203）For the rectangular-ambulatory-plane bend pipe that side straight pipe disconnects, water-oil separating section （203）The grease of tail end exports（204）With surge tank（3）Arrival end be connected；Surge tank（3）Tail portion top be equipped with run through The gas phase inlet tube of tank wall（7）, gas phase inlet tube（7）Lower section be equipped with grease chamber（4）, grease chamber（4）Bottom end with run through tank The oil gas vent pipe of body sidewall（5）It is connected, oil gas vent pipe（5）It is connected with production facility waterborne by pipeline；Oil gas goes out Mouth pipe（5）The tank wall of side is equipped with water outlet pipe（6）, water outlet pipe（6）Tail end and next stage water re-injection system phase Connection.

2. deep-sea oil gas water separation device according to claim 1, it is characterised in that：The collector tube（102）It dips down Tiltedly, liquid-phase outlet（106）Position be less than its arrival end position.

3. deep-sea oil gas water separation device according to claim 1 or 2, it is characterised in that：The water-oil separating section（203） Straight pipe length be more than collector tube（102）Length.

4. deep-sea oil gas water separation device according to claim 3, it is characterised in that：The grease chamber（4）Top be equipped with Horn mouth, bell-mouthed top are located at surge tank（3）The top of middle oil water surface.