Oil and gas field waste liquid treatment system

Abstract

The utility model discloses an oil and gas field waste liquid treatment system, which solves the problem that the discharge standard of oil field waste water is difficult to reach by adopting a single treatment technology, and comprises an ozone oxidation unit, a pH (Potential of Hydrogen) regulation unit, a flocculation precipitation unit, a filter press, an evaporator, a centrifugal machine and an adsorption unit, wherein an inlet of the ozone oxidation unit is connected with a drilling and production waste liquid pipeline, an outlet end of the ozone oxidation unit is connected with an inlet end of the pH adjusting unit, an outlet end of the pH adjusting unit is connected with an inlet end of the flocculation precipitation unit, and an outlet end of the flocculation precipitation unit is connected with an inlet end of the filter press. A first outlet of the filter press is connected with an inlet end of the evaporator, an outlet end of the evaporator is connected with an inlet end of the centrifugal machine, and a first outlet of the centrifugal machine is connected with an inlet end of the adsorption unit. According to the utility model, the treated effluent meets the water quality use requirement, the recycling of the flow-back liquid is realized, and the filter residue meets the landfill standard.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas fields, in particular to an oil and gas field waste liquid treatment system. Background Art

[0002] The composition of oil and gas field wastewater is complex, including crude oil, organic matter, inorganic matter, inorganic salts and microorganisms. The main pollutants are dispersed oil, floating oil, emulsified oil and a small amount of dissolved oil. The characteristics of oilfield wastewater: large quantity and wide range, high B0D and COD content, high salt content, flammable, high temperature, easy oxidation and decomposition. Therefore, the treatment of oilfield production wastewater becomes difficult. At present, the commonly used treatment technologies for oilfield wastewater are physical method, chemical method and biological method. Sometimes it is difficult to meet the discharge standards of oilfield wastewater using a single treatment technology. Therefore, several process combinations are usually used to form a multi-stage treatment process, so as to achieve the standard discharge and recycling of oilfield wastewater. In recent years, with the rapid development of oilfield wastewater treatment technology, new oilfield wastewater treatment technologies have emerged at home and abroad. However, there are still many problems in the current oilfield wastewater treatment technology, which needs further research to achieve better breakthroughs. Utility Model Content

[0003] The utility model provides an oil and gas field waste liquid treatment system to solve the technical problem that it is difficult to reach the discharge standard of oil field waste water by adopting a single treatment technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The present application provides an oil and gas field waste liquid treatment system, comprising an ozone oxidation unit, a pH adjustment unit, a flocculation precipitation unit, a filter press, an evaporator, a centrifuge, and an adsorption unit; wherein:

[0006] The inlet of the ozone oxidation unit is connected to the drilling waste liquid pipeline, the outlet of the ozone oxidation unit is connected to the inlet of the pH adjustment unit, the outlet of the pH adjustment unit is connected to the inlet of the flocculation sedimentation unit, the outlet of the flocculation sedimentation unit is connected to the inlet of the filter press, the first outlet of the filter press is connected to the inlet of the evaporator, the second outlet of the filter press is connected to the inlet of the crushing and cleaning machine, the filter cake after the filtration is crushed and cleaned with clean water for multiple times, the outlet of the evaporator is connected to the inlet of the centrifuge, and the first outlet of the centrifuge is connected to the inlet of the adsorption unit.

[0007] Furthermore, the flocculation and sedimentation unit is provided with a dosing pipe, through which flocculant is added to the flocculation and sedimentation unit. The flocculation and sedimentation unit is provided with an agitator, the upper end of which is fixed to the top of the flocculation and sedimentation unit, and the agitator is electrically connected to the control component.

[0008] Furthermore, the outlet of the crushing and cleaning machine is connected to the inlet of the evaporator and the centrifuge, so that the water used for cleaning the filter cake can be reused.

[0009] Furthermore, the second outlet of the centrifuge is connected to the inlet of a cleaning machine to clean the filter residue after centrifugation again.

[0010] Furthermore, the internal temperature of the evaporator is stepped, with the upper part set as a high temperature zone and the lower part set as a low temperature zone. After evaporation, the generated water vapor is discharged into the sewer through the condenser from the upper part of the evaporator, and the generated concentrated liquid is discharged from the liquid outlet of the lower part of the evaporator.

[0011] Furthermore, the temperature of the high temperature zone is 100-110°C, and the temperature of the low temperature zone is 20-30°C.

[0012] Furthermore, the adsorption unit is provided with 4 to 6 adsorption towers to ensure that at any time there is an adsorption tower in an adsorption state.

[0013] Beneficial effects achieved by the utility model:

[0014] The oil and gas field waste liquid treatment system provided by the utility model can treat and purify the oil and gas field waste liquid, so that the treated water meets the water quality requirements, the return liquid can be reused, and the filter residue meets the landfill standard; it can not only alleviate the problem of water resource shortage, but also reduce the discharge of waste liquid, and carry out comprehensive utilization through resource-based means, provide support for energy conservation and emission reduction, and realize the environmentally friendly and energy-saving development of unconventional oil and gas fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model;

[0016] Reference numerals:

[0017] 1. Ozone oxidation unit; 2. pH adjustment unit; 3. Flocculation and sedimentation unit; 4. Filter press; 5. Evaporator; 6. Centrifuge; 7. Adsorption unit; 8. Crushing and cleaning machine; 9. Cleaning machine; 10. Dosing pipe; 11. Agitator.

[0018] The drawings are only used for illustrative purposes and should not be construed as limitations on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The same or similar numbers correspond to the same or similar parts. The terms describing the positional relationship in the drawings are only used for illustrative purposes and should not be construed as limitations on this patent. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0020] The technical solution of the present utility model is described in detail below in conjunction with the specific drawings.

[0021] like Figure 1 As shown, an oil and gas field waste liquid treatment system includes an ozone oxidation unit 1, a pH adjustment unit 2, a flocculation precipitation unit 3, a filter press 4, an evaporator 5, a centrifuge 6, and an adsorption unit 7; wherein,

[0022] The inlet of the ozone oxidation unit 1 is connected to the drilling waste liquid pipeline, the outlet end of the ozone oxidation unit 1 is connected to the inlet end of the pH adjustment unit 2, the outlet end of the pH adjustment unit 2 is connected to the inlet end of the flocculation sedimentation unit 3, the outlet end of the flocculation sedimentation unit 3 is connected to the inlet end of the filter press 4, the first outlet of the filter press 4 is connected to the inlet end of the evaporator 5, the second outlet of the filter press 4 is connected to the inlet of the crushing and cleaning machine 8, the filter cake after the filtration is crushed and cleaned with clean water for multiple times, the outlet end of the evaporator 5 is connected to the inlet end of the centrifuge 6, and the first outlet of the centrifuge 6 is connected to the inlet end of the adsorption unit 7.

[0023] In a specific embodiment, a dosing pipe 10 is provided on the flocculation sedimentation unit 3, and flocculant is added to the flocculation sedimentation unit 3 through the dosing pipe 10. An agitator 11 is provided in the flocculation sedimentation unit 3, and the upper end of the agitator 11 is fixed to the top of the flocculation sedimentation unit 3, and the agitator 11 is electrically connected to the control component.

[0024] In a specific embodiment, PAC (polyaluminium chloride) and PAM (polyacrylamide) are added into the flocculation and sedimentation unit 3 to form small-particle precipitates for coagulation and flocculation to effectively precipitate large-particle alum.

[0025] In a specific embodiment, the outlet of the crushing and cleaning machine 8 is connected to the inlet of the evaporator 5 and the centrifuge 6, so that the water after cleaning the filter cake is reused.

[0026] In a specific embodiment, the second outlet of the centrifuge 6 is connected to the inlet of the cleaning machine 9 to clean the filter residue after centrifugation again.

[0027] In a specific embodiment, the internal temperature of the evaporator 5 is stepped, with the upper part set as a high temperature zone and the lower part set as a low temperature zone. After evaporation, the generated water vapor is discharged into the sewer through the condenser from the upper section of the evaporator, and the generated concentrated liquid is discharged from the liquid outlet of the lower section of the evaporator.

[0028] In a specific embodiment, the temperature of the high temperature zone is 100-110°C, and the temperature of the low temperature zone is 20-30°C.

[0029] In a specific embodiment, the adsorption unit 7 is provided with 4 to 6 adsorption towers to ensure that at any time there is an adsorption tower in an adsorption state.

[0030] The serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments. The above are only preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An oil and gas field waste liquid treatment system, characterized in that: It comprises an ozone oxidation unit (1), a pH adjustment unit (2), a flocculation precipitation unit (3), a filter press (4), an evaporator (5), a centrifuge (6), and an adsorption unit (7); wherein: The inlet of the ozone oxidation unit (1) is connected to the drilling waste liquid pipeline, the outlet of the ozone oxidation unit (1) is connected to the inlet of the pH adjustment unit (2), the outlet of the pH adjustment unit (2) is connected to the inlet of the flocculation precipitation unit (3), the outlet of the flocculation precipitation unit (3) is connected to the inlet of the filter press (4), the first outlet of the filter press (4) is connected to the inlet of the evaporator (5), the second outlet of the filter press (4) is connected to the inlet of the crushing and cleaning machine (8), the filter cake after the filter press is crushed and cleaned with clean water for multiple times, the outlet of the evaporator (5) is connected to the inlet of the centrifuge (6), and the first outlet of the centrifuge (6) is connected to the inlet of the adsorption unit (7).

2. The oil and gas field waste liquid treatment system according to claim 1, characterized in that: The flocculation and sedimentation unit (3) is provided with a dosing pipe (10), and flocculants are added into the flocculation and sedimentation unit (3) through the dosing pipe (10). The flocculation and sedimentation unit (3) is provided with an agitator (11), and the upper end of the agitator (11) is fixed to the top of the flocculation and sedimentation unit (3). The agitator (11) is electrically connected to the control component.

3. The oil and gas field waste liquid treatment system according to claim 1, characterized in that: The outlet of the crushing and cleaning machine (8) is connected to the inlet of the evaporator (5) and the centrifuge (6), so that the water used to clean the filter cake is reused.

4. The oil and gas field waste liquid treatment system according to claim 1, characterized in that: The second outlet of the centrifuge (6) is connected to the inlet of the cleaning machine (9) to clean the filter residue after centrifugation again.

5. The oil and gas field waste liquid treatment system according to claim 1, characterized in that: The internal temperature of the evaporator (5) is stepped, with the upper portion being set as a high temperature zone and the lower portion being set as a low temperature zone. After evaporation, the generated water vapor is discharged from the upper portion of the evaporator through a condenser into the sewer, and the generated concentrated liquid is discharged from the liquid outlet of the lower portion of the evaporator.

6. The oil and gas field waste liquid treatment system according to claim 5, characterized in that: The temperature of the high temperature zone is 100-110°C, and the temperature of the low temperature zone is 20-30°C.

7. The oil and gas field waste liquid treatment system according to claim 1, characterized in that: The adsorption unit (7) is provided with 4 to 6 adsorption towers, ensuring that at any time there is an adsorption tower in an adsorption state.

Images