CN1179891C

CN1179891C - Process for treating oil field sewage

Info

Publication number: CN1179891C
Application number: CNB01118163XA
Authority: CN
Inventors: 傅绍斌; 曾玉彬
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-05-18
Filing date: 2001-05-18
Publication date: 2004-12-15
Anticipated expiration: 2021-05-18
Also published as: CN1320562A

Abstract

The present invention relates to a method for processing oil field sewage. The present invention is characterized in that a composite ion regulating agent comprising magnesium and zinc inorganic salt, high molecular polymers and alkali compounds is added in the sewage, and the composite ion regulating agent reacts with the sewage in a multifunctional reactor; the water can enter a water injection system via deposition filtration, be discharged or return a thermal recovery boiler after being softened. The method of the present invention greatly reduces lime consumption, has good processing effects, reduces sludge generation amount in processing processes, enlarges sewage processing range and can process the oil field sewage with low mineralization degree, high temperature and low temperature.

Description

A kind of process for treating oil field sewage

Technical field

The invention belongs to the oil-field development technical field, a kind of oil field of more specifically saying so produces the treatment process of sewage.

Background technology

Want simultaneously the output oily(waste)water in oilfield development process, these sewage must could further use through further handling.At publication number is to propose a kind of " oilfield injection water treatment method " in the patent application of CN1175657A, it to the effect that adds in sewage handles based on the treatment agent of calcium hydroxide, pass through certain treatment scheme again, the sewage after will handling at last injects the oilbearing stratum displacement of reservoir oil.This method has treatment effect preferably, but also come with some shortcomings: calcium hydroxide consumption (360-560mg/l sewage) bigger than normal, produce more mud, cause the inclined tube in the slurry tank to stop up, sewage disposal can not normally be carried out, and the mud of slurry tank inner bottom part is difficult to outside the drain tank; In addition, this method is not suitable for the processing of the oilfield sewage of low mineralization (as less than 10000mg/l sewage), and the output sewage treatment effect that is lower than 25 ℃ for temperature is also bad.

Summary of the invention

The objective of the invention is to overcome the deficiency of prior art, propose a kind of process for treating oil field sewage with better purification and stabilising effect.

Main technical schemes of the present invention: be that the water conditioner composition is injected into respectively in a kind of multifunctional reactor, under certain mixture strength, react for some time, after sedimentation is filtered, enter injected system, or discharging, or after softening, enter thermal recovery boiler again.

The prescription of the water conditioner that the present invention is used and add-on thereof: the A composition is a 0-450mg/l sewage, and the B composition is a 0-250mg/l sewage, and the C composition is a 0.1-15mg/l sewage.

Described A composition is the inorganic salt of magnesium or zinc, comprises one or both mixtures in sal epsom, zinc sulfate, magnesium chloride, the zinc chloride.

Described B composition comprises one or both mixtures in calcium hydroxide, magnesium hydroxide, sodium hydroxide, the yellow soda ash.

Described C composition comprises the non-ionic type of polyacrylamide, the high molecular polymer of cationic or anionic, and molecular weight is general more than 1,000 ten thousand.

Process for treating oil field sewage of the present invention may further comprise the steps:

(1) in multifunctional reactor under the 0.8-1.5m/s stirring velocity, in sewage, add the A composition successively, reaction 20-100 second; Add the B composition again, react 20-100 second; Add the C composition at last, react 20-200 second; Sewage after the processing is through sedimentation 2-4 minute, gets to send into waterflood system behind its supernatant liquid filtering and be used for the oilbearing stratum displacement of reservoir oil, or discharging, or again through softening back input thermal recovery boiler.For described A composition and B composition, or add any, or the both adds, but can not add.Described A composition can add in the Reactor inlet pipeline.

Multifunctional reactor of the present invention is a known product, is that the JS-I type multifunctional reactor for the production of realification worker company limited is thought in Jing Zhou.

Sewage after the described processing adopts conventional strong acid ion exchange resin to soften processing before sending into thermal recovery boiler.

Advantage of the present invention:

The present invention is owing to adopt water conditioner to adjust agent and multifunctional reactor, therefore can significantly reduce the usage quantity of lime, treatment effect is better, generally speaking, the water quality of reactor outlet is up to standard substantially, and near zero, COD is less than 120mg/l as oil-contg, suspended solids is less than 5mg/l, and the sludge quantity that produces in the reduction treating processes; Method of the present invention enlarges the scope of disposing of sewage, and can handle the oil field output sewage of low mineralization, comprises condensed oil sewage, and can handle the sewage of high temperature and low temperature (being lower than 21 ℃) output; The present invention can hold back the above mud of 90% in the sewage owing to adopt multifunctional reactor, makes that sludge quantity is controlled at about 0.0005% in the outlet sewage, solve the slurry tank bottom discharge mud difficult and jar in an inclined tube blocking problem.

Embodiment

Further specify characteristics of the present invention below by concrete example.

Example 1

Get output sewage sample 1000ml at certain oilfield sewage station, sewage salinity is that 4164.5mg/l, oil-contg are 450mg/l, and on-line velocity is that adding concentration was 5% water conditioner B component (Ca (OH) under 1.0m/s stirred ₂: the NaOH weight ratio is 1: 1) 4.0ml, at interval adding concentration in 35 seconds is 1% cationic polyacrylamide 1.0ml, continues to stir after 40 seconds sedimentation and leaves standstill 2 minutes.Get supernatant liquid and carry out the mensuration of every water-quality guideline, measurement result sees Table 1.As shown in Table 1, method of the present invention can reduce the add-on of dosing total amount and calcium hydroxide.

Example 2

Get output sewage sample 1000ml at certain oilfield sewage station, sewage temperature is 19 ℃, and oil-contg is 150mg/l, and under the stirring velocity of 1.5m/s, adding concentration is 5% water conditioner component A (Mg (OH) ₂With ZnCl ₂Weight ratio is 1: 4) 4.0ml, stir after 40 minutes, adding concentration is 5%NaCO ₃2.5ml at interval adding concentration after 45 seconds is 1% cationic polyacrylamide 0.8ml, continues to stir after 60 seconds sedimentation and leaves standstill 4 minutes, gets the mensuration that supernatant liquid carries out every water-quality guideline, measurement result sees Table 2.As shown in Table 2, method of the present invention can be handled low temperature oil-contaminated water.

Example 3.

Get output sewage sample 1000ml at certain oilfield sewage station, sewage salinity is that 2580.1mg/l, oil-contg are 250mg/l, and under the stirring velocity of 1.2m/s, adding concentration is 5% water conditioner component A (Mgcl ₂With ZnCl ₂Weight ratio is 5: 2) 2.5ml, stir after 30 seconds, adding concentration is 5%NaCO ₃2.0ml at interval adding concentration after 25 seconds is 1% cationic polyacrylamide 1.0ml, continues to stir after 40 seconds sedimentation and leaves standstill 2 minutes.Get supernatant liquid and carry out the mensuration of every water-quality guideline, measurement result sees Table 3.As shown in Table 3, method of the present invention can be handled the oily(waste)water of the oil field output of low mineralization.

Example 4.

Get output sewage sample 1000ml at certain oilfield sewage station, sewage salinity is that 2830mg/l, oil-contg are 260mg/l, and under the 0.8m/s stirring velocity, adding concentration is 5% water conditioner component A (MgCl ₂With ZnCl ₂Weight ratio is 7: 1) 2.5ml, stirred 35 seconds, adding concentration is 5%NaCO ₃2.0ml adding concentration after 28 seconds at interval is 1% cationic polyacrylamide 0.8ml, sedimentation was left standstill 2 minutes after continuing to stir for 40 seconds, got supernatant liquid and carried out every water-quality guideline, and measurement result sees Table 4.As shown in Table 4, but the sewage reuse thermal recovery boiler after handling by method of the present invention.

Example 5

Get output sewage sample 1000ml at certain oilfield sewage station, sewage salinity is that 5510mg/l, oil-contg are 380mg/l, and under the stirring velocity of 1.2m/s, adding concentration is 5%MgSO ₄20ml stirred after 30 seconds, and adding concentration is 5%NaCO ₃3.0ml at interval adding concentration after 35 seconds is 1% cationic polyacrylamide 1.0ml, continues to stir after 40 seconds sedimentation and leaves standstill 2 minutes.Get supernatant liquid and carry out the mensuration of every water-quality guideline, measurement result sees Table 5.As shown in Table 5, the sewage allow compliance with emission standards of the inventive method processing.

Table 1

Project	Always add dose, mg/l	Ca(OH) ₂Add-on, mg/l	Sludge quantity, mg/l
Project	Always add dose, mg/l	Ca(OH) ₂Add-on, mg/l	Sludge quantity, mg/l	CN1175657A	400-600	360-560	500-700
The present invention	210	100	200	CN1175657A	400-600	360-560	500-700

Table 2

Project	Temperature, ℃	PH value	Oil-contg, mg/l	Sulfide, mg/l	Total iron, mg/l	Suspended solid, mg/l	Erosion rate, mm/a
Project	Temperature, ℃	PH value	Oil-contg, mg/l	Sulfide, mg/l	Total iron, mg/l	Suspended solid, mg/l	Erosion rate, mm/a	Output sewage	30-90	6.0	450	20	15	150	1.08
CN1175657A	30-90	8.0	7.0	2.0	0.05	3.0	66	Output sewage	30-90	6.0	450	20	15	150	1.08
CN1175657A	30-90	8.0	7.0	2.0	0.05	3.0	66	Low temperature output sewage	18-25	7.0	150	11	10	189	0.46
The present invention	18-25	7.3	1.0	1.4	0.03	2.5	0.038	Low temperature output sewage	18-25	7.0	150	11	10	189	0.46

Table 3

Project	Salinity, mg/l	PH value	Oil-contg, mg/l	Sulfide, mg/l	Total iron, mg/l	Amount of solid, mg/l	Corrosion, mm/a
Project	Salinity, mg/l	PH value	Oil-contg, mg/l	Sulfide, mg/l	Total iron, mg/l	Amount of solid, mg/l	Corrosion, mm/a	CN1175857A	150000	6.0	4.0	2.0	0.04	3.0	0.058
The present invention	2830	7.0	0	2.0	0.03	2.0	0.039	CN1175857A	150000	6.0	4.0	2.0	0.04	3.0	0.058

Table 4 unit: mg/l

Project	Total hardness	Oil-contg	Suspended substance	Total iron	Total alkalinity	Silicone content	The soluble solids amount
Project	Total hardness	Oil-contg	Suspended substance	Total iron	Total alkalinity	Silicone content	The soluble solids amount	The boiler inlet standard	＜0.1	2.0	2.0	＜0.1	＜2000	50	＜8000
Measured value	0	0	1.2	0.1	12.7	15	2830	The boiler inlet standard	＜0.1	2.0	2.0	＜0.1	＜2000	50	＜8000

Table 5

Project	PH value	COD，mg/l	Petroleum-type, mg/l	Suspended substance, mg/l
Project	PH value	COD，mg/l	Petroleum-type, mg/l	Suspended substance, mg/l	Secondary standard	6.5-8.5	≤120	≤10	≤200
Measured value	8.1	116.5	3.5	5.1	Secondary standard	6.5-8.5	≤120	≤10	≤200

Claims

1. process for treating oil field sewage, it is characterized in that stirring linear velocity be under the condition of 0.8-1.5m/s, the magnesium that in the reactor that fills oilfield sewage, adds 0-450mg/l sewage successively, the zinc inorganic salt, react 20-100 second, the basic cpd that adds 0-250mg/l sewage again, react 20-100 second, the high molecular polymer that adds 0.1-15mg/l sewage at last reacts 20-200 second, the sewage sedimentation after processing 2-4 minute, get its supernatant liquor and send into waterflood system, or discharging, or with supernatant liquor input thermal recovery boiler after softening, for described magnesium, zinc inorganic salt and basic cpd, or add wherein any, or the both adds;

Described high molecular polymer comprises that the molecular weight of polyacrylamide is the non-ionic type more than 1,000 ten thousand, cationic or anionic high molecular polymer.

2. in accordance with the method for claim 1, it is characterized in that described magnesium, zinc inorganic salt comprise one or both mixtures in sal epsom, zinc sulfate, magnesium chloride, the zinc chloride.

3. in accordance with the method for claim 1, it is characterized in that described basic cpd comprises one or both mixtures in calcium hydroxide, sodium hydroxide, the yellow soda ash.

4. in accordance with the method for claim 1, it is characterized in that magnesium, zinc inorganic salt add in the Reactor inlet pipeline.