CN102942262B - Horizontal well fracturing wastewater treatment and resource utilization method - Google Patents

Abstract

Provided is a horizontal well fracturing wastewater treatment and resource utilization method, comprising: using hydrogen peroxide to pre-oxidize to-be-processed fracturing wastewater, then adding kieselguhr, wherein polymeric aluminium chloride is taken as a flocculant and polyacrylamide is taken as a coagulant, coagulating the fracturing wastewater added with kieselguhr, then filtering the supernatant of wastewater after coagulation and static precipitation, performing advanced oxidation combining ozonation and photocatalytic oxidation, filtering the advanced oxidation filtered water by using multi-level microfiltration membrane, adjust the pH of the filtered water to 6.5-7.5, and finally adding a citric acid solution to get the fracturing liquid for formulation of horizontal well fracturing. The method can effectively control COD, SS and petroleum, and Fe2+, Ca2+, Mg2+ and other high-valence cations in the wastewater, therefore the wastewater can fully meet the needs of preparing the fracturing liquid. The processed water has an excellent wastewater resource reuse effect, and the method also helps to protect the environment of oil exploration areas.

Description

The wastewater treatment of a kind of oilfield horizontal well pressure break and resource utilization method

Technical field

The invention belongs to technical field of petroleum extraction, relate to the processing of horizontal well high density pressure break waste water, be specifically related to the wastewater treatment of a kind of oilfield horizontal well pressure break and resource utilization method.

Background technology

Pressure break waste water is a kind of oil field operation special waste, and unprocessed discharge Dui You district's environmental hazard is serious.Water-based fracturing is one of major measure of domestic and international oilfield stimulation at present, and fractured horizontal well is the effective measure of high-efficiency mining low-permeability oil deposit, in each oil field, generally adopts.Pressure break waste water is very harmful to environment.Due to its inherent pollutent complicated and more stable, under elemental effect, be difficult to be degraded, and polluted surrounding environment to a certain extent, bring great ecological environment problem.Therefore, carry out pressure break wastewater processing technology, for eliminating the environmental pollution of pressure break waste water, ensure that normal production and the Sustainable development in oil field have great importance.Because staged fracturing of horizontal well time-continuing process is long so large ten times of the more general waterfrac treatment wastewater flow rates of wastewater flow rate that produce are even more, pollutant discharge amount also increases greatly.Meanwhile, water consumption is also tens times of common waterfrac treatment water consumption, needs a large amount of fresh waters in operation process, carrys out preparing fracturing fluid.But due to the special geographical environment in oil field and weather, water resources is relatively deficient.Newly exploit in addition oil field basic bit in mountain area, road is rugged, and fresh water supply not in time.Therefore, stablize operation water supply problem and be also on the rise, processing on the spot pressure break utilization of wastewater resource just becomes first-selection.Alleviate oily district environmental problem and seem most important, also significant for the normal production and the Sustainable development that ensure oil field.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the object of the present invention is to provide the wastewater treatment of a kind of oilfield horizontal well pressure break and resource utilization method, by preoxidation+pH regulator+coagulation+precipitation+filtration+advanced oxidation+pH regulator+add citric acid solution art breading fractured horizontal well waste water and resource utilization method, using method is simple, respond well.

To achieve these goals, the technical solution used in the present invention is:

The wastewater treatment of oilfield horizontal well pressure break and a resource utilization method, comprise the steps:

Step 1, adds to the hydrogen peroxide of mass concentration 30% in the pending pressure break waste water of thousand times of volumes of one, stirs 1～3min, and standing 30～60min, then adds diatomite by 3g/L;

Step 2, the polyacrylamide (PAM) that the polymerize aluminum chloride that under room temperature, compound concentration is 50g/L (PAC) and concentration are 2g/L;

Step 3, take configuration polymerize aluminum chloride (PAC) as flocculation agent, polyacrylamide (PAM) be coagulant aids, the pressure break waste water of getting after step 1 is processed carries out coagulation, coagulation condition is: 25 ± 1 ℃ of temperature, pH value 9.00 ± 0.05, under 200r/min, stir 1min, under 20r/min, stir 30min, quiet heavy 60min;

Step 4, gets the wastewater supernatant fluid after quiet sinking, and utilizes sand filtration to filter, and filtering velocity is 0.2m/s;

Step 5, gets and filters rear water outlet, carries out advanced oxidation, and advanced oxidation refers to ozone oxidation and photocatalysis and oxidization combined carrying out, and ozone dosage is 20mg/L, and ultraviolet wavelength is 253nm, and rated output is 120W, and the reaction times is 30min;

Step 6, utilizes multistage microfiltration membrane that advanced oxidation is gone out to water filtration, and filtering velocity is 0.2m/s;

Step 7, gets step 6 filtrate, with the dilute hydrochloric acid of mass concentration 1%, regulates pH, makes its pH remain on 6.5～7.5;

Step 8, in the waste water after dilute hydrochloric acid regulates, adding 5mL concentration is the citric acid solution of 10mg/L, then stirs 1～2min, finally makes its pH remain on 6.8～7.2.

Pressure break waste water after the present invention processes can be used for preparing the required fracturing liquid of fractured horizontal well.

Compare with existing preparing fracturing fluid method, water treatment method of the present invention can meet the required requirement of oilfield horizontal well pressure break completely, thereby reaches the object of recycling pressure break waste water; The method can effectively be controlled COD, SS, petroleum-type and the Fe in waste water ²⁺, Ca ²⁺, Mg ²⁺deng high-valence cationic, thereby reach the demand that fully meets waste water preparing fracturing fluid.

The present invention processes water and not only has good waste water reclaiming reuse effect, also contributes to protect the environment in oil production district.The present invention has reduced the required fresh water ratio of traditional water-based fracturing, has greatly cut down frac job cost, and can't follow-up wellsite applications operation impact after the use of the waste water preparing fracturing fluid after processing.This invention has reduced pressure break discharge of wastewater, to protecting oily district environment to have great importance, meets the strategy and policy of country's " energy-saving and emission-reduction ".

Embodiment

Below in conjunction with embodiment, the present invention is described in further details.

Embodiment mono-

Certain horizontal well well site 1# pressure break waste water water sample.

Its resource utilization method comprises the steps:

Step 1 is 30%H by 1mL massfraction ₂o ₂join and fill in the pending pressure break waste water of 1000mL water sample beaker, glass stick stirs 3min, standing half hour; After preoxidation completely, in waste water, add 3g/L diatomite, and regulate wastewater pH to 9.0 with 10% hydrochloric acid;

Step 2, the polyacrylamide (PAM) that the polymerize aluminum chloride that under room temperature, compound concentration is 50g/L (PAC) and concentration are 2g/L;

Step 3, take configuration polymerize aluminum chloride (PAC) as flocculation agent, polyacrylamide (PAM) be coagulant aids, according to coagulation operational condition, be: 25 ± 1 ℃ of temperature, pH value is adjusted to 9.00 ± 0.05, rapid stirring (200r/min) 1min, low rate mixing (20r/min) 30min, quiet heavy 60min, carries out coagulation;

Step 4, takes out the wastewater supernatant fluid after quiet sinking, and utilizes sand filtration by supernatant liquid filtering, and filtering velocity is 0.2m/s;

Step 5, extracts part and filters rear water outlet, enters advanced oxidation module, and this advanced oxidation module is ozone and photocatalysis and oxidization combined treatment unit, and ozone dosage is 20mg/L, and ultraviolet wavelength is 253nm, and rated output is 120W, and the reaction times is 30min;

Step 6, utilizes multistage microfiltration membrane that advanced oxidation is gone out to water filtration, and filtering velocity is 0.2m/s;

Step 7, gets step 6 filtrate, with the dilute hydrochloric acid of mass concentration 1%, regulates pH, makes its pH remain on 7.0;

Step 8, it is 10mg/L solution that citric acid is mixed with to concentration, and adds into 5mL to processing in water, then with glass stick, stirs 2min, finally makes its pH remain on 6.9;

This tests resulting water sample, is fractured horizontal well utilization of wastewater resource water sample.

After measured, the handled water of embodiment mono-is pressed 0.35% guanidine glue dosage by its preparing fracturing fluid, the measured fracturing liquid base fluid viscosity of standing 4h is 47.8mpa.s, and processed waste water preparing fracturing fluid can meet and reaches oil field fracturing fluid general technical specifications (SY/T6376-2008).

Embodiment bis-

Certain horizontal well well site 2# pressure break waste water water sample.

Its resource utilization method comprises the steps:

Step 1 is 30%H by 1mL massfraction ₂o ₂join and fill in the pending pressure break waste water of 1000mL water sample beaker, glass stick stirs 3min, standing half hour; After preoxidation completely, in waste water, add 3g/L diatomite, and regulate wastewater pH to 9.0 with 10% hydrochloric acid;

Step 2, the polyacrylamide (PAM) that the polymerize aluminum chloride that under room temperature, compound concentration is 50g/L (PAC) and concentration are 2g/L;

Step 3, take configuration polymerize aluminum chloride (PAC) as flocculation agent, polyacrylamide (PAM) be coagulant aids, according to coagulation operational condition, be: 25 ± 1 ℃ of temperature, pH value is adjusted to 9.00 ± 0.05, rapid stirring (200r/min) 1min, low rate mixing (20r/min) 30min, quiet heavy 60min, carries out coagulation;

Step 4, takes out the wastewater supernatant fluid after quiet sinking, and utilizes sand filtration by supernatant liquid filtering, and filtering velocity is 0.2m/s;

Step 5, extracts part and filters rear water outlet, enters advanced oxidation module, and this advanced oxidation module is ozone and photocatalysis and oxidization combined treatment unit, and ozone dosage is 20mg/L, and ultraviolet wavelength is 253nm, and rated output is 120W, and the reaction times is 30min;

Step 6, utilizes multistage microfiltration membrane that advanced oxidation is gone out to water filtration, and filtering velocity is 0.2m/s;

Step 7, gets step 6 filtrate, with the dilute hydrochloric acid of mass concentration 1%, regulates pH, makes its pH remain on 6.8;

Step 8, it is 10mg/L solution that citric acid is mixed with to concentration, and adds into 5mL to processing in water, then with glass stick, stirs 2min, finally makes its pH remain on 7.0;

This tests resulting water sample, is fractured horizontal well utilization of wastewater resource water sample.

After measured, the handled water of case study on implementation two is pressed 0.30% guanidine glue dosage by its preparing fracturing fluid, the measured fracturing liquid base fluid viscosity of standing 4h is 40.3mpa.s, and processed waste water preparing fracturing fluid can meet and reaches oil field fracturing fluid general technical specifications (SY/T6376-2008).

Embodiment tri-

Certain horizontal well well site 3# pressure break waste water water sample.

Its resource utilization method comprises the steps:

Step 1 is 30%H by 1mL massfraction ₂o ₂join and fill in the pending pressure break waste water of 1000mL water sample beaker, glass stick stirs 1min, standing half hour; After preoxidation completely, in waste water, add 3g/L diatomite, and regulate wastewater pH to 9.0 with 10% hydrochloric acid;

Step 2, the polyacrylamide (PAM) that the polymerize aluminum chloride that under room temperature, compound concentration is 50g/L (PAC) and concentration are 2g/L;

Step 3, take configuration polymerize aluminum chloride (PAC) as flocculation agent, polyacrylamide (PAM) be coagulant aids, according to coagulation operational condition, be: 25 ± 1 ℃ of temperature, pH value is adjusted to 9.00 ± 0.05, rapid stirring (200r/min) 1min, low rate mixing (20r/min) 30min, quiet heavy 60min, carries out coagulation;

Step 4, takes out the wastewater supernatant fluid after quiet sinking, and utilizes sand filtration by supernatant liquid filtering, and filtering velocity is 0.2m/s;

Step 5, extracts part and filters rear water outlet, enters advanced oxidation module, and this advanced oxidation module is ozone and photocatalysis and oxidization combined treatment unit, and ozone dosage is 20mg/L, and ultraviolet wavelength is 253nm, and rated output is 120W, and the reaction times is 30min;

Step 6, utilizes multistage microfiltration membrane that advanced oxidation is gone out to water filtration, and filtering velocity is 0.2m/s;

Step 7, gets step 6 filtrate, with the dilute hydrochloric acid of mass concentration 1%, regulates pH, makes its pH remain on 7.5;

Step 8, it is 10mg/L solution that citric acid is mixed with to concentration, and adds into 5mL to processing in water, then with glass stick, stirs 1～2min, finally makes its pH remain on 7.1;

This tests resulting water sample, is fractured horizontal well utilization of wastewater resource water sample.

After measured, the handled water of case study on implementation three is pressed 0.40% guanidine glue dosage by its preparing fracturing fluid, the measured fracturing liquid base fluid viscosity of standing 4h is 57.6mpa.s, and processed waste water preparing fracturing fluid can meet and reaches oil field fracturing fluid general technical specifications (SY/T6376-2008).

Claims (1)

1. the wastewater treatment of oilfield horizontal well pressure break and a resource utilization method, is characterized in that, comprises the steps:

Step 1, adds to the hydrogen peroxide of mass concentration 30% in the pending pressure break waste water of thousand times of volumes of one, stirs 1～3min, and standing 30～60min, then adds diatomite by 3g/L;

Step 2, the polyacrylamide (PAM) that the polymerize aluminum chloride that under room temperature, compound concentration is 50g/L (PAC) and concentration are 2g/L;

Step 3, take configuration polymerize aluminum chloride (PAC) as flocculation agent, polyacrylamide (PAM) be coagulant aids, the pressure break waste water of getting after step 1 is processed carries out coagulation, coagulation condition is: 25 ± 1 ℃ of temperature, pH value 9.00 ± 0.05, under 200r/min, stir 1min, under 20r/min, stir 30min, quiet heavy 60min;

Step 4, gets the wastewater supernatant fluid after quiet sinking, and utilizes sand filtration to filter, and filtering velocity is 0.2m/s;

Step 5, gets and filters rear water outlet, carries out advanced oxidation, and advanced oxidation refers to ozone oxidation and photocatalysis and oxidization combined carrying out, and ozone dosage is 20mg/L, and ultraviolet wavelength is 253nm, and rated output is 120W, and the reaction times is 30min;

Step 6, utilizes multistage microfiltration membrane that advanced oxidation is gone out to water filtration, and filtering velocity is 0.2m/s;

Step 7, gets step 6 filtrate, with the dilute hydrochloric acid of mass concentration 1%, regulates pH, makes its pH remain on 6.5～7.5;

Step 8, in the waste water after dilute hydrochloric acid regulates, adding 5mL concentration is the citric acid solution of 10mg/L, then stirs 1～2min, finally makes its pH remain on 6.8～7.2.