CN103936185B - A kind of super Heavy Oil High Temperature waste water treating and reutilizing is in the method for thermal recovery boiler - Google Patents

Abstract

The invention provides a kind of super Heavy Oil High Temperature waste water treating and reutilizing in the method for thermal recovery boiler, in super Heavy Oil High Temperature sewage, add reverse-phase emulsifier, remove the oil emulsion of high-load, then in Cyclonic reactor, add successively high-efficiency decontaminating agent, conditioning stabilizing agent and flocculating agent, oil removing and except solid suspension, carries out sedimentation, Separation of Solid and Liquid; Double-filtration is further removed tiny suspended solid; Super Heavy Oil High Temperature sewage enters the softening processing of two-stage ion-exchanger after being purified stable processing, reaches the thermal recovery boiler water quality standard of tap water. The temperature of the super Heavy Oil High Temperature sewage of this process makes full use, saves large energy, reduces the consumption of thermal recovery boiler fuel, realizes extremely-viscous crude sewage and recycles, and saves clear water resource, improves effects of energy saving and emission reduction and overall economic efficiency.

Description

A method of treating ultra-heavy oil high-temperature sewage and recycling it to a thermal recovery boiler

technical field

The invention relates to the treatment and reuse of sewage, especially the treatment and reuse of ultra-heavy oil high-temperature sewage. The method is scientific and reasonable and has excellent application effect.

Background technique

The classification definition of produced crude oil is thin oil with a viscosity below 1000mPa.s at 50°C, heavy oil with a viscosity between 1000-10000mPa.s, extra-heavy oil with a viscosity of 10000-50000mPa.s, and extra-heavy oil with a viscosity above 50000mPa.s. For super thick oil. Super-heavy oil produced water is a complex system containing solid impurities, microorganisms, dissolved gases, and soluble salts. It is generally characterized by various types of organic matter, high salinity, high oil content, and high content of scaling ions. The characteristics of ultra-heavy oily sewage are "high temperature, high oil content, high suspended solids and high silicon type produced water". Difficulties in purification treatment: (1) The temperature of the extracted sewage is high, reaching 80-90 °C; (2) It contains high content of colloids and asphaltene and carry a large amount of suspended solids such as sediment; (3) Conventional water purifiers lose their effect at 80-90°C due to molecular chain breaks or violent molecular movement of oil and suspended solids. (4) Although the temperature resistance of inorganic water purifiers is good, but the content of suspended solids in super heavy oil production water is too high, inorganic water purifiers and suspended solids in water will produce a large number of flocs, which will reduce the solid-liquid separation efficiency of the equipment, so it is used poor effect. (5) A large number of chemical agents are added during the process of lifting the produced fluid to the ground and dehydrating, and these chemicals remain in the produced water, making the sewage form a stable emulsion. This kind of sewage not only has a high oil content, but also has a high viscosity of ultra-heavy oil, which makes the purification of sewage more complicated and more difficult to deal with. Difficulties in the advanced treatment of ultra-heavy oil produced water: the advanced treatment technology of ultra-heavy oil sewage adopts ion exchange technology, which can reduce the hardness of water to below 0.1mg/L (calculated as CaCO ₃ ), although it has reached the level of steam injection. Boilers require hardness indicators, but the mass concentration of SiO ₂ in super-heavy oil production water is already above 200mg/L or even 250mg/L. Silicate scale, if the sewage is used to generate steam, silicon scale will be formed in the thermal recovery boiler or steam injection pipeline, which is far more harmful than calcium scale. At present, the water quality index of the treated sewage reuse steam injection boiler requires that the SiO ₂ mass concentration is below 100mg/L. It is not ideal to use lime or caustic softening method to treat SiO ₂ in ultra-heavy oil high-temperature sewage, because: ① A large amount of softening agent is added to generate a large amount of sludge, which increases the difficulty of sludge disposal. ②The operating parameters are complicated, and the chemical softening process may change due to multiple parameters, which makes the control difficult. ③The process flow is long and the equipment is increased. Chemical softening method needs to increase process facilities such as softening tank, silicon removal tank, clarification tank, etc., and needs to increase a variety of chemical dosing equipment. ④ High investment and processing costs.

The method provided by the invention performs advanced treatment on the high-temperature sewage of super-heavy oil separated from the oil well. Recycling of high-temperature sewage saves water resources, protects the environment, and has significant economic and social benefits.

Contents of the invention

The purpose of the present invention is to effectively solve the production problems of the prior art in view of the super heavy oil high temperature sewage treatment and reuse method, achieve the effect of super heavy oil high temperature sewage treatment, and make a demonstration for enterprises to save energy and reduce consumption.

The purpose of the present invention is achieved in this way: a method for treating super heavy oil high temperature sewage and recycling it to a thermal recovery boiler, which is implemented in steps;

Step 1: Dosing reverse-phase demulsifier to the ultra-heavy oil high-temperature sewage placed in the separation tank to implement oil-water separation, the dosage is 20-50mg/L;

Among them, the inverse demulsifier is composed of cationic polyether quaternary ammonium salt, 3.0G polyamide-amine, and nonionic polyether; the mixing ratio of the two kinds is 1:1-2:1, and the mixing ratio of the three kinds is 1: 2:1, the oil content of the treated water is less than 5mg/L, and the suspended solid content is less than 10mg/L;

Step 2: Put the effluent from step 1 in a cyclone reactor, and add purifying agent, conditioning stabilizer, and coagulant in sequence, wherein the dosage of purifying agent is 100-200 mg/L, and the dosage of conditioning stabilizer is 50-100 mg/L , the dosage of coagulant is 6-10mg/L;

The purifying agent is composed of polyaluminum chloride, polyaluminum sulfate, and polysilicate aluminum chloride. The mixing ratio of the two kinds is 1:1-2:1, and the mixing ratio of the three kinds is 1:1:1;

The conditioning stabilizer is composed of polyphosphate, organic phosphate, and sodium hydroxide. The mixing ratio of the two is 1:20-1:25, and the mixing ratio of the three is 1:1:20-1:1. :25;

Among them, the coagulant is composed of anionic polyacrylamide and nonionic polyacrylamide, and the mixing ratio of the two is 2:1-3:1; the molecular weight range of anionic and nonionic is 15 million-20 million;

Step 3 Put the effluent from step 2 in a slant plate settling tank for sedimentation. After buffering, pump it into the first-stage double filter material filter and the second-stage fine filter to remove the remaining oil and suspended matter in the water, so that the oil content of the effluent is 0mg/L , the suspended solids content is less than 2mg/L; then enter the first-level sodium-type cation exchange softener for treatment to make the total hardness ≤0.1mg/L; enter the second-level chelating ion-exchange resin softener for treatment to make calcium ions, magnesium Ions and iron ions are both less than or equal to 0.02mg/L, and they can be reused in thermal recovery boilers.

According to the method, the viscosity of super heavy oil in the treated high-temperature sewage is >50000Mpa.s, the temperature of the sewage is 85-90°C, the pH is 7.5-8.5, the salinity is 2000-4000mg/L, the oil content is 10000-20000mg/L, and the suspended solid content is 500-1000mg/L, hardness 40-80mg/L, silica content 200-250mg/L.

Mechanism and efficiency of the present invention: the water quality treated by the method meets the requirements of China Petroleum and Natural Gas Thermal Recovery Boiler Water Quality Standard (Q/sy1275-2010). The process adopts a gravity-swirl reaction-filtration process with energy saving and consumption reduction, as well as an impact-resistant and stable water quality and water volume adjustment device. The softened water treatment uses a chelating ion exchange resin softening system without silicon removal treatment, replacing the The complex chemical softening system with large amount of sludge and high treatment cost makes the operation easier and more convenient. A joint station is calculated based on the daily average water treatment volume of 4.0×10 ⁴ m ³ , saving heat energy (temperature of heavy oil sewage, fuel oil) and sewage discharge The recovery of crude oil and clear water resources totals 1139×10 ⁵ yuan per year, demonstrating technological progress.

Description of drawings

The invention will be further described below in conjunction with the accompanying drawings.

The accompanying drawing is a flow chart of the ultra-heavy oil high-temperature sewage treatment process;

As shown in the figure: Sewage → regulating tank → reaction buffer tank → cyclone reactor → inclined plate settling tank → filter buffer tank → double filter material filter → fine filter → sodium type cation exchange softener → chelating ion exchange Resin softener → heat recovery boiler.

detailed description

Below in conjunction with embodiment the invention is further illustrated.

Example 1

High-temperature sewage of ultra-heavy oil in an oilfield, sewage temperature 90°C, pH 8.5, salinity 4000mg/L, oil content 20000mg/L, suspended solid content 1000mg/L, hardness 80mg/L, silica content 250mg/L;

Processing steps:

1) Add 50mg/L reverse phase demulsifier to super heavy oil high temperature sewage, reverse phase demulsifier is cationic polyether quaternary ammonium salt, 3.0G polyamide-amine mixture, the mixing ratio is 1:1, using metering pump, Wet dosing;

2) Add 200mg/L high-efficiency purifying agent to the water in step 1), and react in a special swirling flow reactor. The reaction time is 45s. The high-efficiency purifying agent is a mixture of polyaluminum chloride and polyaluminum sulfate, and the mixing ratio is 2 : 1, using metering pumps, wet dosing;

3) Add conditioning stabilizer 100mg/L to the water in step 2), react in a special swirl reactor, the reaction time is 47s, the conditioning stabilizer is a mixture of polyphosphate, organic phosphate and sodium hydroxide; the mixture The ratio is 1:1:20, using metering pumps, wet dosing;

4) Add 10mg/L coagulant to the water in step 3), and react in a special cyclone reactor, the reaction time is 60s, the coagulant is a mixture of anionic polyacrylamide and nonionic polyacrylamide, and the mixing ratio is 2 :1, the molecular weight range is 15 million; using metering pumps, wet dosing;

5) The water treated in step 4) enters the inclined plate settling tank for sedimentation, and then buffers in the filter buffer tank, and then pumps it into the first-stage double-filter filter and the second-stage fine filter through the lift pump for two Stage filtration to remove remaining oil and suspended solids in the water, so that the oil content of the effluent is 0mg/L, and the suspended solid content is less than 2mg/L; it enters the first-stage sodium-type cation exchange softener to make the total hardness ≤0.1mg/L; enters the second-stage In the grade chelating ion exchange resin softener, the content of calcium ions, magnesium ions, and iron ions are all ≤0.02mg/L; enter the thermal recovery boiler for reuse.

Example 2

High-temperature sewage of ultra-heavy oil in an oilfield, the sewage temperature is 85°C, pH is 7.5, salinity is 2000mg/L, oil content is 10000mg/L, suspended solid content is 500mg/L, hardness is 40mg/L, silica The content is 200mg/L;

Processing steps:

1) Add 20mg/L reverse phase demulsifier to super heavy oil high temperature sewage; reverse phase demulsifier is 3.0G polyamide-amine, non-ionic polyether mixture, the mixing ratio is 2:1, using metering pump, wet method Dosing;

2) Add 100mg/L high-efficiency purifying agent to the water in step 1), and react in a special cyclone reactor for a reaction time of 45s. The high-efficiency purifying agent is a mixture of polyaluminum sulfate and polysilicon aluminum chloride; the mixing ratio 1:1, using metering pumps, wet dosing;

3) Add 50 mg/L conditioning stabilizer to the water in step 2), and react in a special cyclone reactor for 60 seconds. The conditioning stabilizer is a mixture of organic phosphate and magnesium chloride; the mixing ratio is 1:20, using Metering pump, wet dosing;

4) Add 6mg/L coagulant to the water in step 3), and react in a special cyclone reactor, the reaction time is 48s, the coagulant is a mixture of anionic polyacrylamide and nonionic polyacrylamide, and the mixing ratio is 3 :1, the molecular weight range is 20 million; using metering pumps, wet dosing;

5) Transfer the water treated in step 4) to the water treated in step 4, enter the inclined plate settling tank for sedimentation, and then buffer in the filter buffer tank, and then pump it into the first-stage double-filter filter and the second-stage filter through the lift pump. Two-stage filtration is carried out in the first-stage fine filter to remove residual oil and suspended solids in the water, so that the oil content of the effluent is 0 mg/L, and the suspended solid content is less than 2 mg/L; it enters the first-stage sodium-type cation exchange softener to make the total hardness ≤0.1mg/L; enter the secondary chelating ion exchange resin softener, so that the content of calcium ions, magnesium ions, and iron ions are all ≤0.02mg/L; enter the thermal recovery boiler for reuse.

Example 3

High-temperature sewage of ultra-heavy oil in an oil field, the sewage temperature is 90°C, pH is 8.0, salinity is 3000mg/L, oil content is 15000mg/L, suspended solid content is 800mg/L, hardness is 60mg/L, silica The content is 220mg/L;

Processing steps:

1) Add 30mg/L reverse phase demulsifier to super heavy oil high temperature sewage; reverse phase demulsifier is cationic polyether quaternary ammonium salt, 3.0G polyamide-amine, nonionic polyether mixture, the mixing ratio is 1:2 : 1, using metering pumps, wet dosing;

2) Add 150mg/L high-efficiency purifying agent to the water in step 1), and react in a special cyclone reactor with a reaction time of 48s. The high-efficiency purifying agent is a mixture of polyaluminum chloride, polyaluminum sulfate, and polysilicon aluminum chloride ;The mixing ratio is 1:1:1, using metering pumps, dosing by wet method;

3) Add 80mg/L conditioning stabilizer to the water in step 2), and react in a special cyclone reactor with a reaction time of 49s. The conditioning stabilizer is a mixture of polyphosphate, organic phosphate, and calcium hydroxide; The mixing ratio is 1:1:25, and the metering pump is used, and the wet method is added;

4) Add 8mg/L coagulant to the water in step 3), and react in a special swirl reactor, the reaction time is 60s, the coagulant is a mixture of anionic polyacrylamide and nonionic polyacrylamide, and the mixing ratio is 3 :1, the molecular weight range is 18 million; using metering pumps, wet dosing;

5) The water treated in step 4) enters the inclined plate settling tank for sedimentation, and then buffers in the filter buffer tank, and then pumps it into the first-stage double-filter filter and the second-stage fine filter through the lift pump for two Stage filtration to remove remaining oil and suspended solids in the water, so that the oil content of the effluent is 0mg/L, and the suspended solid content is less than 2mg/L; it enters the first-stage sodium-type cation exchange softener to make the total hardness ≤0.1mg/L; enters the second-stage In the grade chelating ion exchange resin softener, the content of calcium ions, magnesium ions, and iron ions are all ≤0.02mg/L; enter the thermal recovery boiler for reuse.

The purified water obtained by the above method is determined to have an oil content of 0 mg/L, suspended solids ≤ 2 mg/L, calcium ions, magnesium ions, and iron ions ≤ 0.02 mg/L, without silicon removal treatment, reaching The water quality standard (Q/sy1275-2010) for oilfield sewage reuse wet steam generators stipulates that the water supply should meet the standard.

3. Production effect verification:

See Table 1 and Table 2 for the measured water quality indicators of the purified water obtained by the above method.

Table 1 Super heavy oil high temperature sewage treatment

Table 2 Super heavy oil high temperature sewage treatment

From the data in Table 1 and Table 2, it can be seen that the oil content in the treated water is 0mg/L, the suspended solids are ≤2mg/L, and the contents of calcium ions, magnesium ions, and iron ions are all ≤0.02mg/L, and there is no need for silicon removal treatment. Reach the water quality standard (Q/sy1275-2010) for wet steam generators for oilfield wastewater reuse.

The manufacturers of the first-stage double filter material filter, the second-stage fine filter, the first-stage sodium-type cation exchange softener and the second-stage chelating ion-exchange resin softener selected by the present invention are oil field companies.

Cationic polyether quaternary ammonium salt, 3.0G polyamide-amine, nonionic polyether, polyaluminum chloride, polyaluminum sulfate, polysilicon aluminum chloride, polyphosphate, organic phosphate anion, polypropylene The manufacturer of amide and nonionic polyacrylamide is Xinjiang Karamay Sanda Co., Ltd. Chemical Company.

Claims (1)

1. A method for treating ultra-heavy oil high-temperature sewage and reusing it in a thermal recovery boiler. The ultra-heavy oil viscosity in the high-temperature sewage is >50000Mpa.s, the sewage temperature is 85-90°C, pH7.5-8.5, and the salinity is 2000 -4000mg/L, oil content 10000-20000mg/L, suspended solids content 500-1000mg/L, hardness 40-80mg/L, silica content 200-250mg/L, characterized in that the method is implemented in steps: Step 1. Add an inverse demulsifier to the super heavy oil high-temperature sewage placed in the separation tank to implement oil-water separation, and the dosage is 20-50 mg/L; the inverse demulsifier is composed of cationic polyether quaternary ammonium salt, 3.0G polyamide-amine, non-ionic polyether; the mixing ratio of the three kinds is 1:2:1, the oil content of the treated water is less than 5mg/L, and the suspended solid content is less than 10mg/L; Step 2. Put the effluent from step 1 in a cyclone reactor, and add purifying agent, conditioning stabilizer, and coagulant in sequence, wherein the dosage of purifying agent is 100-200mg/L, and the dosage of conditioning stabilizer is 50-100mg/L L, the dosage of coagulant is 6-10mg/L; The cleaning agent is composed of polyaluminum chloride, polyaluminum sulfate, and polysilicate aluminum chloride, and the mixing ratio of the three kinds is 1:1:1; the conditioning stabilizer is composed of polyphosphate, organic phosphate , sodium hydroxide, the mixing ratio of the three kinds is 1:1:20 or 1:1:25; the coagulant is composed of anionic polyacrylamide and nonionic polyacrylamide, and the mixing ratio of the two kinds is 2:1-3:1; the molecular weight range of anion and non-ion is 15 million-20 million; Step 3. Put the effluent from step 2 in a slant plate settling tank for sedimentation. After buffering, pump it into the first-stage double filter material filter and the second-stage fine filter to remove the remaining oil and suspended matter in the water, so that the oil content of the effluent is 0mg/ L, the suspended solids content is less than 2mg/L; then enter the first-level sodium type cation exchange softener for treatment, so that the total hardness ≤ 0.1mg/L; enter the second-level chelating ion exchange resin softener for treatment, so that calcium ions, Magnesium ion and iron ion content are both ≤0.02mg/L, which can be reused in thermal recovery boilers.