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CN-118666373-B - High emulsification sewage treatment plant of oil gas field

CN118666373BCN 118666373 BCN118666373 BCN 118666373BCN-118666373-B

Abstract

The invention belongs to the technical field of oil and gas exploitation, and particularly relates to a high-emulsification sewage treatment device for an oil and gas field. The high-emulsification sewage treatment device for the oil and gas field comprises an electric flocculation cabin and a cyclone cabin, wherein the electric flocculation cabin is provided with a cyclone pipe, sewage enters the electric flocculation cabin through the cyclone pipe, an outer annular electrode, an inner annular electrode and a central annular electrode are sequentially and coaxially fixedly arranged in the electric flocculation cabin at intervals from outside to inside, the polarities of the outer annular electrode and the central annular electrode are opposite to those of the inner annular electrode, and after the sewage enters the electric flocculation cabin, the sewage firstly passes through an annular space between the outer annular electrode and the inner annular electrode and then passes through an annular space between the inner annular electrode and the central annular electrode. The invention can efficiently separate impurities in sewage and occupies small space.

Inventors

  • WANG XINGWANG
  • DANG WEI
  • HU CHANGCHAO
  • LI WEI
  • TANG ZHIWEI
  • LIU WENYUAN

Assignees

  • 中国石油化工股份有限公司
  • 中国石油化工股份有限公司石油勘探开发研究院

Dates

Publication Date
20260508
Application Date
20230316

Claims (6)

  1. 1. The high-emulsification sewage treatment device for the oil and gas field is characterized by comprising an electric flocculation cabin (5) and a cyclone cabin (22), wherein a cyclone tube (4) is arranged on the electric flocculation cabin (5) along the tangential direction, sewage enters the electric flocculation cabin (5) through the cyclone tube (4), a micro-bubble generator (3) is arranged on the cyclone tube (4), the micro-bubble generator (3) is connected with the top of the cyclone cabin (22) through a return air pipeline (21), An outer layer annular electrode (7), an inner layer annular electrode (61) and a central annular electrode (91) are coaxially and fixedly arranged in the electric flocculation chamber (5) at intervals from outside to inside in sequence, wherein the polarities of the outer layer annular electrode (7) and the central annular electrode (91) are opposite to the polarity of the inner layer annular electrode (61), A mud collecting cabin (8) is arranged below the electric flocculation cabin (5), a baffle cylinder (6) and a central column tube (9) are fixedly arranged in the electric flocculation cabin (5) at intervals, the central column tube (9) is positioned at the inner side of the baffle cylinder (6), an outer annular electrode (7) is fixedly arranged on the inner wall of the electric flocculation cabin (5), an inner annular electrode (61) is fixedly arranged on the baffle cylinder (6), a central annular electrode (91) is fixedly arranged on the outer wall of the central column tube (9), the electric flocculation cabin (5) and the mud collecting cabin (8) are separated by arranging a mud sliding hopper (81), the mud sliding hopper (81) is arranged into a conical shape with a downward tip, a mud collecting opening (82) is arranged at the lower end of the mud sliding hopper (81), the baffle cylinder (6) is arranged into a conical shape with a downward tip, a mud sliding tube (62) is fixedly arranged at the lower end of the baffle cylinder (6), mud enters the mud collecting cabin (82) and extends downwards through the mud sliding hopper (82), After entering the electroflocculation chamber (5), the sewage firstly passes through the annular space between the outer annular electrode (7) and the inner annular electrode (61), then passes through the annular space between the inner annular electrode (61) and the central annular electrode (91), and then enters the cyclone chamber (22).
  2. 2. An oil and gas field high emulsification sewage treatment device according to claim 1, characterized in that at least one gas injection cyclone (10) is arranged in the cyclone compartment (22), and the central pillar (9) extends upwards into the cyclone compartment (22) and is connected with the gas injection cyclone (10).
  3. 3. The oil and gas field high emulsification sewage treatment device according to claim 2, wherein a plurality of branch pipes (92) are uniformly arranged at the top end of the central column pipe (9) along the circumferential direction, and each branch pipe (92) is connected with each gas injection cyclone (10).
  4. 4. An oil and gas field high emulsification sewage treatment device according to claim 2, characterized in that an air injection distribution cabin (15) and a compressor (14) are arranged on the top of the cyclone cabin (22) and are connected with each other, the air injection distribution cabin (15) is connected with each air injection cyclone (10), the compressor (14) pressurizes and conveys the air on the top of the cyclone cabin (22) into the air injection distribution cabin (15), and the air injection distribution cabin (15) injects the air into each air injection cyclone (10) respectively.
  5. 5. An oil and gas field high emulsification sewage treatment device according to claim 4, characterized in that the upper part of the cyclone chamber (22) and the upper part of the electric flocculation chamber (5) are both provided with oil discharge pipelines (18), two oil discharge pipelines (18) are both provided with gas separation bags (19), one end of each gas separation bag (19) is connected with the backflow gas pipeline (21), and the other end is connected with an oil discharge port (20).
  6. 6. A device for treating high emulsification sewage in oil and gas fields according to claim 3, characterized in that a water outlet pipe (11) is provided on the bulkhead of the cyclone chamber (22), and the water outlet pipe (11) is located below the gas injection cyclone (10).

Description

High emulsification sewage treatment plant of oil gas field Technical Field The invention belongs to the technical field of oil and gas exploitation, and particularly relates to a high-emulsification sewage treatment device for an oil and gas field. Background In oil gas development, along with continuous breakthrough and wide application of a fracture network, horizontal well perforation and horizontal well multistage fracturing technology, unconventional oil gas such as shale oil, shale gas and the like are gradually exploited in scale, and in the production process, high-emulsified sewage represented by fracturing flowback fluid in a larger scale is generated. The fracturing flowback fluid is used as the operation wastewater generated after the oil and gas field production increasing measures, contains guar gum, preservative, gel breaker, petroleum and other various chemical additives, carries more sand and solid phase impurities from stratum, has the characteristics of high viscosity, high emulsification degree, high solid phase content, difficult oil-water-mud separation, large water quality fluctuation and the like, and needs to be reasonably treated in a compliance mode, and mainly comprises two modes of reinjection and centralized treatment of pulling and transportation. When the fracturing flowback fluid is reinjected, the requirement on the selection of reinjected stratum is high, the method is not suitable for large-scale reinjection, and the environmental protection risk is high, so that the fracturing flowback fluid is generally treated in a centralized way by pulling and transporting the tank truck to a joint station. Before the fracturing flowback fluid enters the combined station system, pretreatment is needed to remove solid impurities, suspended matters and colloid, and the problems that the normal operation of a production system is disturbed, a large amount of treatment agents are consumed, the oil-water separation effect is affected, the quality of the treated water does not reach the standard, and the water injection development effect is affected are avoided. The commonly used fracturing flowback fluid pretreatment method mainly comprises a magnetic separation method, an SSF suspended sludge method, a biochemical method and the like. The method has the advantages of large magnetic powder consumption in the magnetic separation process, difficult recovery of magnetic powder, high treatment cost and large sludge yield, the SSF suspended sludge method is greatly influenced by water quality fluctuation, flocculation is still required to be formed by adding flocculating agent and coagulant aid, the sludge layer effect is not easy to control, the biodegradability of the fracturing flowback fluid is poor, a certain nutrient substance is required to be added when the biochemical method is adopted, the treatment cost is high, and the treatment effect is greatly influenced by water temperature and environmental temperature. Therefore, the method has the advantages of capturing impurities efficiently, realizing rapid separation of flocs and purification of water quality, concentrating sludge, realizing on-site treatment and on-site reinjection of purified water, and is a development trend of high-emulsification sewage treatment technology represented by fracturing flowback fluid. Disclosure of Invention Aiming at the technical problems, the invention aims to provide a high-emulsification sewage treatment device for an oil-gas field, which can efficiently demulsify and separate impurities in sewage and occupies small space. The invention is especially suitable for the oil-water-mud separation treatment of wastewater generated by operations such as fracturing, drilling, acidification, well flushing and the like, is also suitable for the conventional sewage treatment of offshore platforms with large solid content, strict water quality indexes and places with limited places and places needing skid-mounting, and is especially suitable for the sewage treatment with high emulsified oil content and high solid phase impurity content. According to the invention, the high-emulsification sewage treatment device comprises an electric flocculation cabin and a cyclone cabin, wherein a cyclone tube is arranged on the side wall of the electric flocculation cabin, sewage enters the electric flocculation cabin through the cyclone tube, an outer annular electrode, an inner annular electrode and a central annular electrode are coaxially and fixedly arranged in the electric flocculation cabin at intervals from outside to inside in sequence, the polarities of the outer annular electrode and the central annular electrode are opposite to those of the inner annular electrode, and after entering the electric flocculation cabin, the sewage firstly passes through an annular space between the outer annular electrode and the inner annular electrode and then passes through an annular space between the inner annular electrode an