US 7,438,129 B2Granted

Water treatment method for heavy oil production using calcium sulfate seed slurry evaporation

AssigneeGE Ionics, Inc.

InventorWilliam F. Heins

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Abstract

A process for treating produced water to generate high pressure steam. Produced water from heavy oil recovery operations is treated by first removing oil and grease. Feedwater is then acidified and steam stripped to remove alkalinity and dissolved non-condensable gases. Pretreated produced water is then fed to an evaporator. Up to 95% or more of the pretreated produced water stream is evaporated to produce (1) a distillate having a trace amount of residual solutes therein, and (2) evaporator blowdown containing substantially all solutes from the produced water feed. The distillate may be directly used, or polished to remove the trace residual solutes before being fed to a steam generator. Steam generation in a packaged boiler, such as a water tube boiler having a steam drum and a mud drum with water cooled combustion chamber walls, produces 100% quality high pressure steam for down-hole use.

Claims61

Dependent claims

A process for producing steam for downhole injection in the recovery of heavy oil, said process comprising:

(a) providing an oil/water mixture gathered from an oil/water collection well;
(b) separating oil from said oil/water mixture to provide an oil product and a produced water product containing oil therein;
(c) de-oiling said oil containing produced water product to at least partially provide an evaporator feedwater stream, said evaporator feedwater stream comprising water, dissolved gases, and dissolved solutes, said dissolved solutes comprising calcium, sulfate, and silica;
(d) providing an evaporator having a plurality of heat transfer elements, a liquid containing sump reservoir, and a recirculating pump to recycle a concentrated brine form said sump reservoir to said plurality of heat transfer elements;
(e) acidifying said feedwater to convert alkalinity to carbon dioxide, and steam stripping said carbon dioxide and said dissolved gases from said evaporator feedwater stream;
(f) injecting said evaporator feedwater stream into said evaporator and evaporating a portion of said feedwater stream to produce said concentrated brine;
(g) recirculating said concentrated brine in said evaporator, said concentrated brine comprising a slurry comprising water, dissolved solutes, calcium sulfate, and silica crystals;
(h) distributing said concentrated brine on a first surface of at least one of said plurality of heat transfer elements to generate a steam vapor;
(i) compressing said steam vapor to produce a compressed steam vapor;
(j) directing said compressed steam vapor to a second surface of at least one of said plurality of heat transfer elements to condense said compressed steam vapor and to form a distillate;
(k) collecting said distillate;
(l) discharging at least some of said concentrated brine as an evaporator blowdown stream;
(m) introducing said distillate stream into a steam generator, to produce
(i) high pressure steam, and
(ii) a boiler blowdown stream, said boiler blowdown stream comprising water and residual dissolved solids;
(n) injecting said high pressure steam in an injection wells to fluidize oil present in a selected geological formation, to produce an oil and water mixture;
(o) gathering said oil/water mixture.

14 more elements

A process for producing steam for downhole injection in the recovery of heavy oil, said process comprising:

(a) providing an oil/water mixture gathered from an oil/water collection well;
(b) separating oil from said oil/water mixture to provide an oil product and a produced water product containing oil therein;
(c) pretreating said produced water product, said pretreating comprising de-oiling said oil containing produced water product to at least partially provide a feedwater stream, said feedwater stream comprising water, dissolved gases, said dissolved gases comprising alkalinity, and dissolved solutes, said dissolved solutes comprising silica;
(d) providing an evaporator having a plurality of heat transfer elements, a liquid containing sump reservoir, and a recirculating pump to recycle a concentrated brine from said sump reservoir to said plurality of heat transfer elements;
(e) acidifying said feedwater stream to convert said alkalinity to carbon dioxide and then steam stripping said carbon dioxide from said feedwater stream;
(f) recirculating said concentrated brine;
(g) adding said feedwater stream to said concentrated brine before directing said concentrated brine to which said feedwater stream has been added to said plurality of heat transfer elements;
(h) distributing said concentrated brine on a first surface of at least one of said plurality of heat transfer elements to generate a steam vapor;
(i) compressing said steam vapor to produce a compressed steam vapor;
(j) directing said compressed steam vapor to a second surface of at least one of said plurality of heat transfer elements to condense said compressed steam vapor and to form a distillate;
(k) collecting said distillate;
(l) discharging at least some of said concentrated brine as an evaporator blowdown stream;
(m) introducing said distillate into a steam generator, to produce
(i) high pressure steam,
(ii) a boiler blowdown stream, said boiler blowdown stream comprising water and residual dissolved solids;
(n) injecting said high pressure steam in injection wells to fluidize oil present in a selected geological formation, to produce an oil and water mixture;
(o) gathering said oil/water mixture.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/149,072Filed 8 Jun 2005 · continuation in part
Priority: 7 May 1999
Published: US 2005/0022989 A122 Dec 2005
Granted: 21 Oct 2008
Term ends: Not estimatedThe source records don’t support an estimate.

Classification22 codes

C02F 1/048
By distillation or evaporation: purification of waste water by evaporation
C02F 1/04
By heating: by distillation or evaporation
E21B 43/2406
Using heat, e.g. steam injection: steam assisted gravity drainage [SAGD]
E21B 43/2408
Steam assisted gravity drainage [SAGD]: sAGD in combination with other methods

Family

Application60/133,172Us provisional application · filed 7 May 1999
Application09/566,622Parent of this continuation-in-part · filed 8 May 2000
Application10/307,250Parent of this continuation-in-part · filed 30 Nov 2002
Application10/868,745Parent of this continuation-in-part · filed 9 Jun 2004
Application60/578,810Us provisional application · filed 9 Jun 2004
US 2005/0279500 A1Pre-grant publication · published 22 Dec 2005
US 7,150,320 B2Parent of this continuation-in-part
US 7,077,201 B2Parent of this continuation-in-part
US 6,733,636 B1Parent of this continuation-in-part
US 2003/0127226 A1Published application
US 2005/0022989 A1Published application
US 7,438,129 B2This patent

From the US filing history. Foreign family members aren’t listed.