CN-117566932-B - Efficient treatment and sludge concentration device for fracturing flowback fluid

CN117566932BCN 117566932 BCN117566932 BCN 117566932BCN-117566932-B

Abstract

The invention provides a high-efficiency treatment and sludge concentration device for fracturing flowback fluid, which comprises an electric flocculation device, a sedimentation cylinder and a cyclone tube, wherein the electric flocculation device comprises a plurality of flocculation tubes which are arranged side by side and connected in series, a U-shaped joint connected between the adjacent flocculation tubes, and a power supply for supplying power to the flocculation tubes, the sedimentation cylinder is used for separating oil, water and sludge in the fracturing flowback fluid, and the cyclone tube is connected with the outlet end of the electric flocculation device and extends into the sedimentation cylinder along the tangential direction of the cross section of the sedimentation cylinder. The invention is provided with the electric flocculator and the sedimentation cylinder, the electric flocculator demulsifies the severely emulsified fracturing flowback fluid, and flocculates oil drops, suspended impurities and solid impurities in the fracturing flowback fluid into floccules, so that the oil, water and mud can be separated by the subsequent sedimentation cylinder.

Inventors

WANG XINGWANG
DANG WEI
TANG ZHIWEI
HU CHANGCHAO
SI YANXIAO
WANG LILI
TAN WENJIE
BI CAIXIA
DING PENGYUAN

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: 20220805

Claims (12)

1. The utility model provides a high-efficient processing and sludge concentration device of flowing back is returned in fracturing which characterized in that includes: The electric flocculation device (1) comprises a plurality of flocculation pipes (11) which are arranged side by side and connected in series, U-shaped connectors (12) connected between the adjacent flocculation pipes and a power supply (13) for supplying power to the flocculation pipes, the adjacent flocculation pipes are connected through the U-shaped connectors to form a bending pipeline, and the turbulent flow effect of the elbow is beneficial to the formation and aggregation growth of flocs; A sedimentation cylinder (2) for separating oil, water and mud in the fracturing flowback fluid, wherein the separated mud is deposited and concentrated at the bottom of the sedimentation cylinder, a first conical mud sliding hopper (21) and a conical cyclone separation cylinder (25) are arranged in the sedimentation cylinder (2), The first conical mud sliding hopper (21) divides the sedimentation cylinder into a rotational flow bin (22) and a mud collecting bin (23), the lower end of the first conical mud sliding hopper is provided with a mud collecting opening (211) which communicates the rotational flow bin with the mud collecting bin, A conical baffle (5) is arranged on the central axis of the sedimentation cylinder (2), the conical baffle is positioned above the first conical slide mud hopper (21), the conical baffle is arranged into an inverted cone, the diameter of the upper end of the conical baffle is larger than the diameter of the top end of the conical cyclone separation cylinder and smaller than the inner diameter of the sedimentation cylinder, A mud sliding pipe (6) is communicated between the bottom end of the conical baffle (5) and the mud collecting bin (23), a baffle cylinder (7) is arranged above the conical baffle (5), the diameter of the upper end of the baffle cylinder is equal to that of the sedimentation cylinder (2), the diameter of the lower end of the baffle cylinder is smaller than that of the upper end of the conical baffle (5), a baffling channel is formed between the baffle cylinder and the conical baffle, An oil collecting tank (95) is arranged in the sedimentation cylinder (2), the oil collecting tank (95) is used for controlling the liquid level, so that an air cavity used for being connected with a return air pipeline (84) is formed at the top of the sedimentation cylinder (2), the efficient treatment and sludge concentration device for the fracturing flowback fluid further comprises a return water pipeline (85) extending out of the sedimentation cylinder (2), and the first conical slide hopper is positioned below the return water pipeline (85); and the cyclone tube (3) is connected with the outlet end of the electric flocculation device, extends into the sedimentation cylinder along the tangential direction of the cross section of the sedimentation cylinder, and the reflux water pipeline (85) is arranged below the cyclone tube (3).
2. The efficient treatment and sludge concentration device for fracturing flowback fluid according to claim 1, wherein an insulating flange (14) is arranged between the flocculation pipe (11) and the U-shaped joint (12), the flocculation pipe (11) comprises a hollow pipe (111) connected with a cathode of the power supply (13) and a rod-shaped anode (112) connected with an anode of the power supply, the hollow pipe (111) is an electric conductor, and the rod-shaped anode is sleeved in the hollow pipe in a clearance mode.
3. The efficient treatment and sludge concentration device for fracturing flowback fluid according to claim 2, further comprising a dissolved air water release pipe (83) extending into the settling cask (2), and a microbubble generator (82) connecting the return water pipe (85) and the dissolved air water release pipe (83) together, wherein the dissolved air water release pipe is arranged along a tangential direction of a cross section of the settling cask (2) for transporting dissolved air water generated by the microbubble generator (82) into the settling cask (2).
4. A device for efficient treatment and sludge concentration of fracturing flowback fluid according to claim 3, characterized in that the dissolved air water release pipeline (83) is above the cyclone tube (3), the microbubble generator (82) is connected with the top end of the settling cask (2) through a return air pipeline (84), and the return water pipeline (85) is connected with the microbubble generator (82) through a return water pump (81).
5. The device for efficiently treating and concentrating sludge in a fracturing flowback fluid according to claim 4, wherein a sludge discharge port (231) is formed at the bottom end of the sludge collection bin.
6. The device for efficiently treating fracturing flowback fluid and concentrating sludge according to claim 5, wherein a vortex breaker (24) is further arranged in the sedimentation cylinder (2), and the vortex breaker is arranged below the cyclone tube (3) and right above the sludge collection port (211) and can prevent the cyclone intensity in the cyclone bin (22) from being transferred to the sludge collection bin (23).
7. The apparatus for efficient treatment of fracturing flow-back fluid and sludge concentration of claim 6, wherein the inner diameter of the upper end of the conical cyclone separation cylinder is smaller than the inner diameter of the lower end.
8. The device for efficiently treating fracturing flowback fluid and concentrating sludge according to claim 7, wherein a second conical slide sludge hopper (26) is arranged at the top end of the conical cyclone separation cylinder (25), the diameter of the upper end of the second conical slide sludge hopper is equal to that of the sedimentation cylinder (2), and the diameter of the lower end of the second conical slide sludge hopper is equal to that of the top end of the conical cyclone separation cylinder (25).
9. The apparatus for efficient treatment and sludge concentration of frac flowback fluid of claim 8 wherein said tapered baffle is positioned above said second tapered slide hopper (26).
10. The efficient treatment and sludge concentration device for fracturing flowback fluid according to claim 1, wherein an oil drain port (91) and a water drain port (92) are arranged on the shell of the sedimentation cylinder (2) above the baffle cylinder (7), the oil drain port (91) is located above the water drain port (92), and the oil drain port (91) and the water drain port (92) are respectively arranged at two radial ends of the sedimentation cylinder (2).
11. The device for efficiently treating and concentrating sludge in the fracturing flowback fluid according to claim 10, wherein the oil collecting groove (95) is buckled at the oil discharge port, and an opening is arranged at the top of the oil collecting groove (95).
12. The efficient treatment and sludge concentration device for fracturing flowback fluid according to claim 11, wherein a conical wide-mouth oil-water separation cylinder (93) is arranged above the baffling cylinder (7), the oil drain port (91) is arranged above the conical wide-mouth oil-water separation cylinder (93), and the water drain port (92) is arranged at a position of the sedimentation cylinder (2) corresponding to the lower part of the conical wide-mouth oil-water separation cylinder (93).

Description

Efficient treatment and sludge concentration device for fracturing flowback fluid Technical Field The invention belongs to the technical field of oilfield sewage treatment, and particularly relates to a high-efficiency treatment and sludge concentration device suitable for fracturing flowback fluid, wellhead replacement fluid, well flushing and operation wastewater, which can also be used for conventional oil and gas field produced water treatment with high emulsification degree, high solid impurities and limited sites. Background With the gradual maturity of fracture network fracturing, volume fracturing, horizontal well through-the-layer fracturing and horizontal well multistage fracturing technologies, low-permeability unconventional oil gas reserves represented by compact oil gas, shale oil gas and the like are gradually developed on a large scale. While producing oil and gas, a large amount of fracturing flowback fluid is also produced. The fracturing flowback fluid contains more than ten chemical additives such as a thickening agent, a cross-linking agent and the like, and has strong sand carrying capacity. Also because of the multiple additives, the fracturing flowback fluid has the characteristics of high viscosity, high emulsification degree, high content of large-particle mechanical impurities, high content of TDS (total dissolved solids), difficult oil-water sedimentation separation, large water quality fluctuation and the like. At present, two treatment modes of the fracturing flowback fluid are mainly adopted, one is to treat the reinjection stratum by the fracturing flowback fluid, but the mode has high selection requirement on the reinjection stratum, the residual reinjection space is reduced year by year, the method is not suitable for large-scale injection, and the environmental protection risk is high. Another way is to pull the large-scale fracturing flowback fluid to a joint station for centralized treatment by a tank truck. However, if a large amount of fracturing flowback fluid directly enters the joint station, the normal operation of a production system is seriously disturbed, a large amount of treatment agents are consumed or the treatment effect of the agents is reduced, the dehydration of crude oil and the removal of oil and suspended matters in water are affected, and thus the water quality injected after treatment does not reach the standard. Therefore, pretreatment such as magnetic separation treatment, SSF suspended sludge treatment, biochemical treatment and the like is generally required to be performed on the fracturing flowback fluid before the fracturing flowback fluid enters the combined station system, so as to remove solid impurities, suspended matters and colloids in the fracturing flowback fluid and reduce the turbidity of a water sample. The method has the advantages and disadvantages of large quantity of magnetic powder required by magnetic separation, difficult recovery of the magnetic powder, high treatment cost and large quantity of dangerous waste sludge, poor water quality fluctuation resistance of the SSF suspension sludge treatment technology, difficulty in controlling sludge layer effect due to the addition of flocculant and coagulant aid, poor biodegradability of fracturing flowback fluid, large water quality fluctuation and difficult survival of microorganisms in winter. In addition, the production well areas of dense oil gas and shale oil gas are dispersed, the distribution and the storage space of an environment-friendly storage pool are insufficient, and the leakage risk exists. Therefore, the development of fracturing flowback fluid skid-mounted treatment technology can rapidly capture impurities, realize rapid separation of flocs and water purification, concentrate sludge and realize on-site recovery and reinjection, and is a development trend of the technology. Disclosure of Invention Aiming at the technical problems, the invention aims to provide a high-efficiency treatment and sludge concentration device for fracturing flowback fluid, which can be applied to demulsification, deoiling and purification of fracturing flowback fluid with high emulsification degree and high solid impurities, well head replacement fluid, well flushing and other oilfield operation wastewater difficult to separate. In addition, the invention has the characteristics of closed oxygen isolation, high efficiency, continuity, no addition (less addition), low operation cost, small device volume and easy skid-mounting, can be used for common oil and gas field sewage treatment with more solid impurities, limited space and high water quality purification requirements, and is particularly suitable for short-flow and high-efficiency treatment of common oil and gas field sewage with more emulsified oil drops and more solid impurities. The invention provides a device for efficiently treating fracturing flowback fluid and concentrating sludge, which is characterized by comprising an el