Optimization Approach to Produced Water Management

Dan Tormey, Ph.D., P.G.Cardno Ltd.

What is the Produced Water “Problem”?

• Large volumes of water produced by oil and gas• Typically saline• May contain other contaminants• Volumes typically greater than can be

accommodated by injection• Source of Public Concern

Waste or Resource?

AustraliaMost states define

produced water as a waste

Queensland redefinition: Beneficial if “no harm” can be demonstrated

United StatesALL produced water

considered a waste

Prohibition on surface discharge unless benefits to wildlife or agriculture can be demonstrated

A New Source of Water

Treated produced water used for:

Australia:• Crop irrigation• Golf course

irrigation• Stock watering• Industrial uses• Stream

discharge

Ecuador, Columbia, Indonesia:

• Encouraging beneficial reuse as a component of the social license to operate

Displaces demand on public potable water supplies

USA:• Crop irrigation• Stock watering• Groundwater

recharge • Wildlife habitat

support

Variable:• Salinities• Temperatures• Other compounds• Volume and change

over time

Produced waters not created equal

Beneficial uses intensely site-specific• Agriculture• Industrial• Ornamental plants

NO ONE SOLUTION

How to Optimize for a Site-Specific Solution?

FOUR STEPS1. Understand the

source

2. Understand the potential use

3. Understand the available treatment technologies

4. Have backup plans

Step 1: Understand the Source

• How much water produced over time?• What is the quality over time?• What is the temperature over time?• How much can be injected without

undermining resource recovery?

Step 2: Understand the Beneficial Uses

Survey of local

opportunities• Local water

users/needs?• Ocean outfall?• Stream

discharge?• Geothermal?

Evaluate compatibilities• Water quality

requirements• Compatibility of

produced water (treated or untreated) with the use

Step 3: Understand Treatment Technologies

Untreated• Compatibility and reliability

assessments

Injection• Compatibility assessment• Affect on other groundwater

resources

Variety of Treatment Options• Ion exchange• Membranes (including RO)• Mechanical vapor recompression• Air stripping• Precipitation• Dilution

Characterize Source Water

Identify Beneficial Uses and Water Quality Requirements

Pair Beneficial Uses with Treatment - Reverse Osmosis

- Mechanical Vapor Recompression

- Dilution

- I/X; Organic Removal

- Other Options

Compare Treatment

Technologies and their Cost Effectiveness

Diluted/Moderately Treated- Limited Agricultural

- Private Use

Untreated- Aquifer Injection

- Industrial Uses

- Limited Ag

Fully Treated- Unrestricted Agricultural Use

- Discharge to surface waters

OPTIMIZATION• Balance cost and

reliability• Create a menu of

uses that – Support full time

operation– Consider

potential loss of some uses

• Understand changes over time

• Create backup plans to enhance system reliability

California Example

• Receiving water and upland studies

• Designed and completed entire approval process

• Coordinate with equipment vendors for performance standards

Optimization Model indicated that:

• Reverse Osmosis Treatment was needed to sell or discharge the produced water

• Brine could be reinjected to producing formation

Australia Example

Optimization Model used to determine menu of Beneficial Reuses

No Treatment: • Stock watering• Industrial

washdown• Dilution/discharge

Treated: – Irrigation– Stream discharge

– Limited opportunity for injection

– Mechanical Vapor Recompression selected for treatment

Ecuador/Columbia/Indonesia• Large volumes of

produced water with limited beneficial reuse

• Growing concern over Social License to Operate

• Fact-Finding and Benchmarking

• Optimization Model applied over a national territory

• Establish stakeholder relationships

• Opportunity to learn from USA and Australia experience

Summary• A new view of produced

water: New resource, not a waste

• Regulatory hurdles easing as the beneficial uses are demonstrated

• Regulatory uncertainty and urgent need together create a confusing marketplace

• Local solutions needed• Optimization approach to

balancing source, end users, and treatment technologies