METHOD AND APPARATUS FOR TREATING NATURAL GAS AND OIL WELL WASTE WATERS FOR REMOVAL OF CONTAMINANTS AND DISSOLVED SOLIDS

• US 20150368137A1
• Filed: 02/01/2014
• Published: 12/24/2015
• Est. Priority Date: 02/01/2013
• Status: Abandoned Application

• Current Assignee: Addleman Enterprises, Inc., Lake Country FracWater Specialists, LLC
• Original Assignee: Addleman Enterprises, Inc., Lake Country FracWater Specialists, LLC
• Inventors: MILLER, Francis C., ADDLEMAN, Steve
• Application Number:
  US14/765,027
• Publication Number:
  US 20150368137A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C02F 1/004 using large scale industrial sized filters
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 1/463 by electrocoagulation
• CPC Class Codes: C02F 1/52 by flocculation or precipitation of suspended impurities C02F1/463 takes precedence
• CPC Class Codes: C02F 1/5236 using inorganic agents
• CPC Class Codes: C02F 1/56 Macromolecular compounds
• CPC Class Codes: C02F 1/66 by neutralisation; pH adjustment for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58
• CPC Class Codes: C02F 1/72 by oxidation C02F1/4672 takes precedence
• CPC Class Codes: C02F 1/722 Oxidation by peroxides
• CPC Class Codes: C02F 1/78 with ozone C02F1/4672 takes precedence
• CPC Class Codes: C02F 11/121 by mechanical de-watering
• CPC Class Codes: C02F 2101/108 Boron compounds
• CPC Class Codes: C02F 2103/10 from quarries or from mining activities
• CPC Class Codes: C02F 2103/365 from petrochemical industry (e.g. refineries)
• CPC Class Codes: C02F 2209/00 Controlling or monitoring parameters in water treatment
• CPC Class Codes: C02F 2209/03 Pressure
• CPC Class Codes: C02F 2209/05 Conductivity or salinity
• CPC Class Codes: C02F 2209/055 Hardness
• CPC Class Codes: C02F 2209/11 Turbidity
• CPC Class Codes: C02F 5/02 : Softening water by precipitation of the hardness
• CPC Class Codes: C02F 5/06 : using calcium compounds
• CPC Class Codes: C02F 9/00 : Multistage treatment of water, waste water or sewage

Abstract

A method for treating wastewater is disclosed. The method is useful in particular for treating wastewater that is generated from the process of drilling, hydraulic fracturing and/or cleaning a bore of an oil or natural gas well bore. The method may include performing cold lime softening of the wastewater to form waste salt floes, filtration of waste salt floes, ozonation of the filtrate from the filtration, and reverse osmosis of the filtrate to produce a purified permeate.

Claims

1. A method for treating wastewater, the method comprising:

a) delivering a stream of the wastewater to a clarification subsystem in which organic matter and/or suspended solids are removed in a multi stage combined oxidation, coagulation, flocculation and filtration process and oxidizing organic matter and separating at least one of organic matter and suspended solids within the clarification subsystem to produce a clarified wastewater stream;

b) delivering the clarified wastewater stream to a softening subsystem, causing precipitation of dissolved waste salts within the softening subsystem, and separating the precipitated waste salts to produce a softened wastewater stream;

c) delivering the softened wastewater stream to a first reaction vessel, and injecting nano-sized bubbles of ozone and hydrogen peroxide into the second oxidized wastewater stream to produce an oxidized wastewater stream; and

d) delivering the oxidized wastewater stream to a carbon filtration subsystem, causing decomposition of residual ozone in the oxidized wastewater stream, and separating trace residual organic matter from the first oxidized wastewater stream to produce a second oxidized wastewater stream;

e) delivering the second oxidized wastewater stream to a first reverse osmosis subsystem and separating a first portion of remaining dissolved waste salts from the second oxidized wastewater stream within the first reverse osmosis subsystem to produce a first permeate wastewater stream.

2. The method of claim 1, further comprising delivering the first permeate wastewater stream to a second reverse osmosis subsystem and removing dissolved boron salts within the second reverse osmosis subsystem to a produce a second permeate wastewater stream having a concentration of dissolved boron salts of less than 5 parts per million, and a concentrate having a concentration of dissolved boron salts greater than the concentration of dissolved boron salts in the first permeate wastewater stream.

3. The method of claim 2, further comprising delivering the concentrate to a magnesium hydroxide co-precipitation subsystem, causing precipitation of dissolved boron salts by addition of magnesium hydroxide to the concentrate, and separating the precipitated boron salts from the concentrate to produce a first purified wastewater stream.

4. The method of claim 1, wherein the clarified wastewater stream is at an elevated temperature greater than the temperature of the first permeate wastewater stream, and wherein the method further comprised delivering the clarified wastewater stream through a first passageway of a heat exchanger while delivering the first permeate wastewater stream through a second passageway of a heat exchanger in counterflow with respect to the direction of flow of the clarified wastewater stream flowing through the first passageway of the heat exchanger.

5. The method of claim 1, further comprising providing a programmable logic controller in communication with the clarification subsystem, the softening subsystem, the oxidation subsystem, the carbon filtration subsystem, the first reaction vessel, the first reverse osmosis subsystem, the second reverse osmosis subsystem, and the co-precipitation subsystem, measuring concentration of waste salts in the wastewater, and operating the subsystems to produce the second permeate wastewater stream and the first purified wastewater stream according to an algorithm executed by the programmable logic controller, the operation of the algorithm based upon the concentration of waste salts in the wastewater.

6. The method of claim 1, wherein organic matter and suspended solids are removed from the stream of wastewater using oxidation by ozone in conjunction with a metal chloride.

7. The method of claim 6, wherein the metal chloride is aluminum chlorhydrate.

8. The method of claim 1, wherein the softening subsystem includes means for separating and dewatering of the precipitated waste salts and clarification and filtration of supernatant fluid within a single unbaffled horizontal flow vessel to produce the softened wastewater stream.

9. The method of claim 1, wherein the softening subsystem includes means for separating the precipitated waste salts from supernatant fluid within a single unbaffled horizontal flow vessel to produce the softened wastewater stream.

10. The method of claim 1, wherein the clarified wastewater stream is delivered through an electric field generator and an orifice of the softening subsystem while injecting at least one of sodium carbonate, sodium hydroxide or calcium hydroxide to cause the precipitation of dissolved waste salts within the softening subsystem.

11. A method for separation and dewatering of precipitated carbonate salts from wastewater, the method comprising:

a) providing a filter comprised of a housing comprised of a bottom wall, a side wall, and an outlet;

a first filter medium comprised of a bottom panel disposed along the bottom wall, and a side panel disposed along the side wall; and

a first inflatable bladder disposed between the bottom wall of the housing and the bottom panel of the filter medium;

b) adding sodium carbonate to a stream of the wastewater to result in a pH of not less than 10.1;

c) delivering the stream of the wastewater into the housing of the filter through a floating boom conduit at a fluid velocity exiting the conduit of less than 0.15 feet per second;

d) maintaining the residence time of the wastewater in the filter for at least 60 minutes;

e) maintaining the fluid velocity of the wastewater in the filter at less than 0.0015 feet per second;

thereby causing separation of the precipitated carbonate salts from the wastewater to produce clarified fluid in the housing of the filter; and

f) withdrawing the clarified fluid from the housing of the filter through a floating skimming funnel located distally from the floating boom conduit.

12. A method for separation and dewatering of precipitated carbonate salts from wastewater, the method comprising:

a) adding sodium carbonate to a stream of the wastewater to result in a pH of not less than 10.1;

b) delivering the stream of the wastewater into a decanting tank comprising a side wall and a conical bottom wall through an upwardly oriented inlet conduit at a velocity of less than 0.15 feet per second, the upwardly oriented inlet conduit having a discharge outlet at least one foot above the lowest portion of the conical bottom wall;

c) maintaining the residence time of the wastewater in the decant tank for at least 60 minutes;

d) maintaining the fluid velocity of the wastewater within the decant tank at less than 0.0015 feet per second, thereby causing separation of the precipitated carbonate salts from the wastewater to produce clarified fluid in the decanting tank;

e) withdrawing the clarified fluid from the decanting tank through a floating skimming funnel disposed in an upper region of the decanting tank;

f) withdrawing a slurry of settled precipitated carbonate salts through a valve in communication with an outlet nozzle joined to the conical bottom wall and of sufficient size to prevent blockage with settled precipitated salts; and

g) delivering the slurry of precipitated salts into a filter and separating the slurry into solid precipitated salts and a filtrate.

13. The method of claim 12, wherein the amount of sodium carbonate added to the wastewater is sub-stoichiometric.

14. The method of claim 13, further comprising adding at least one of sodium hydroxide or calcium hydroxide if the sub-stoichiometric amount of sodium carbonate added is not sufficient to maintain the pH at a minimum of 10.1

15. A method for precipitation of hardness salts from wastewater, the method comprising:

a) delivering a stream of the waste water through a first conduit;

b) injecting into the first conduit a stoichiometric or sub-stiochiometric quantity of sodium carbonate relative to the quantity of calcium and a stoichiometric or sub-stiochiometric quantity of sodium hydroxide or calcium hydroxide relative to the quantity of magnesium in the wastewater into the stream of wastewater absent control of the pH of the wastewater;

c) delivering the sodium carbonate and sodium hydroxide treated stream of the wastewater through a second conduit while applying an electric field to the treated stream;

d) delivering the treated stream of wastewater through an orifice disposed in the second conduit and causing the formation of seed crystals of waste salt in the treated stream of wastewater to produce waste salt precipitate-containing wastewater;

e) collecting a volume of waste salt precipitate-containing wastewater in a first holding vessel and holding the volume in the first holding vessel during further precipitation of waste salts, thereby forming a slurry of precipitated waste salts; and

f) delivering the slurry of precipitated waste salts into a filter and separating the slurry into solid precipitated waste salts and a filtrate.

16. The method of claim 15, further comprising delivering a stream of the slurry of precipitated waste salts from the first holding vessel, and causing mixing of a coagulant solution with the precipitated waste salt containing stream.

17. The method of claim 16, further comprising collecting a volume of the mixed coagulant solution and precipitated waste salt containing stream in a second holding vessel.

18. The method of claim 17, further comprising delivering a stream of the coagulant solution and precipitated waste salt containing volume from the second holding vessel through a third conduit while injecting a flocculant solution into the third conduit, and causing mixing of the flocculant solution with the coagulant solution and precipitated waste salt containing stream and further causing formation of waste salt flocs suspended in the stream flowing through the third conduit.

19. A computer implemented method for treating wastewater by a treatment system comprising instrumentation for measuring total dissolved solids, pH, total suspended solids, heavy metals concentrations, organic contamination concentrations and species, and calcium and alkalinity of the incoming wastewater and of the processed wastewater during processing, and comprising a programmable logic controller programmed with an algorithm comprising:

a) storing requirements of influent wastewater delivered to a reverse osmosis system and the process effluent requirements in a memory of the controller;

b) utilizing influent calcium and hardness data, calculate, anticipate and set feed conditions and inventory requirements for soda ash and lime stored in the memory of the controller to control a wastewater softening process;

c) utilizing influent calcium and hardness data to calculate softener feed and bypass ratios in the wastewater softening process;

d) utilizing influent wastewater and outlet calcium and hardness data to provide feedback information to adjust the feed conditions of the soda ash and lime in a cold soda/lime softening chemical injection portion of the wastewater softening process;

e) utilizing influent calcium and hardness data to calculate the quantity of precipitated salts to be produced by the wastewater softening process;

f) utilizing influent calcium and hardness data to calculate and the fluid flow rate and quantity of precipitated solids plus the measured suspended solids present in the influent wastewater and to calculate, anticipate and set feed conditions and inventory requirements for coagulants and flocculants in a wastewater flocculation process;

g) utilizing data from optical comparative instrumentation at the inlet to a dewatering and filtration system to detect the size of the flocculated particles in a wastewater stream entering the filtration system;

h) utilizing data from turbidity instrumentation and/or polish filter pressure drop anomalies to determine unsatisfactory conditions;

i) utilizing data from turbidity and polish filter pressure drop anomalies to adjust the feed conditions of the coagulant and/or flocculants in the a flocculation chemical injection portion of the wastewater flocculation process;

j) utilizing data from inline residual organic matter analysis instrumentation to anticipate and set operating conditions of an ozonation subsystem;

k) utilizing data from residual ozone and residual organic matter analysis instrumentation to further adjust the operation of the ozonation subsystem;

l) utilizing data from residual ozone and residual organic matter analysis instrumentation at the outlet of the carbon filter to provide alarm annunciation and automated responses to instances of unacceptable levels of residual ozone and/or organic matter in ozonated filtrate delivered to a reverse osmosis system;

m) utilizing data from interstage pressure instrumentation, reverse osmosis feed conductivity instrumentation, and historical and calculated performance data on the membranes along with data on softening subsystem effluent calcium and alkalinity levels to anticipate the operating conditions of the reverse osmosis subsystem;

n) utilizing influent calcium and hardness data to calculate reverse osmosis feed and bypass ratios;

o) utilizing the pressure data and data from reverse osmosis permeate effluent conductivity instrumentation to further adjust the operation of the reverse osmosis process and provide alarm annunciation of and automated responses to instances of reverse osmosis permeate which is not within specifications;

p) utilizing continuously obtained data from pressure instrumentation on all process influent and effluent conduits and all inter subsystem process conduits during normal flow conditions to determine normal process-specific operating ranges of back pressure on each influent, effluent or inter sub system process conduit;

q) utilizing the process-specific operating range of back pressure on each influent, effluent or inter sub system process conduit to determine anomalies indicative of a pumping failure or a break in a process conduit; and

r) in the event of a pumping failure or a break in a process conduit, initiating an alarm and process exhaust fan operation in conjunction with a programmed, sequential shutdown of the wastewater treatment system.

20. A method for treating wastewater, the method comprising:

a) delivering a stream of the wastewater to a clarification subsystem in which organic matter and/or suspended solids are removed in a multi stage combined oxidation, coagulation, flocculation and filtration process and oxidizing organic matter and separating at least one of organic matter and suspended solids within the clarification subsystem to produce a clarified wastewater stream;

b) delivering the clarified wastewater stream to a first reaction vessel, and injecting nano-sized bubbles of ozone and hydrogen peroxide into the second oxidized wastewater stream to produce an oxidized wastewater stream; and

c) delivering the oxidized wastewater stream to a carbon filtration subsystem, causing decomposition of residual ozone in the oxidized wastewater stream, and separating trace residual organic matter from the first oxidized wastewater stream to produce a second oxidized wastewater stream;

d) delivering the second oxidized wastewater stream to a first reverse osmosis subsystem and separating a first portion of remaining dissolved waste salts from the second oxidized wastewater stream within the first reverse osmosis subsystem to produce a first permeate wastewater stream.

21. The method of claim 20, further comprising delivering the first permeate wastewater stream to a second reverse osmosis subsystem and removing dissolved boron salts within the second reverse osmosis subsystem to a produce a second permeate wastewater stream having a concentration of dissolved boron salts of less than 5 parts per million, and a concentrate having a concentration of dissolved boron salts greater than the concentration of dissolved boron salts in the first permeate wastewater stream.

22. The method of claim 21, further comprising delivering the concentrate to a magnesium hydroxide co-precipitation subsystem, causing precipitation of dissolved boron salts by addition of magnesium hydroxide to the concentrate, and separating the precipitated boron salts from the concentrate to produce a first purified wastewater stream.

23. The method of claim 20, wherein the clarified wastewater stream is at an elevated temperature greater than the temperature of the first permeate wastewater stream, and wherein the method further comprised delivering the clarified wastewater stream through a first passageway of a heat exchanger while delivering the first permeate wastewater stream through a second passageway of a heat exchanger in counterflow with respect to the direction of flow of the clarified wastewater stream flowing through the first passageway of the heat exchanger.