Gas reinjection and flaring reduction Norway's experience - Steinar Nja (Norway Petroleum Directorate)

Gas Reinjection Presentation at Workshop on”CDM Methodology Issues related to Gas Flaring” Amsterdam 03.12.08 By Steinar Njå, Project Director, Norwegian Petroleum Directorate Carbon Limit, Amsterdam, 03.12.08

Content of presentation
Gas reinjection in general
Purpose of gas reinjection
Gas and Reservoir properties
Injection facilities
The economics of gas reinjection
The Norwegian Case
Legal framework
Some field cases
Gas reinjection related to CDM
Reinjection schemes
Injection Monitoring
Closing remarks
Carbon Limit, Amsterdam, 03.12.08

Main stages in Production and Capture 06/07/09 Reservoir Separation Oil Gas Flare Sale ” Utilization” Flue gas CO2 Capture CO2 Storage Clean flue gas Gas Reinjection
Products:
Electricity
Chemicals
LNG
Others
Fuel CO2 Reinjection ? Well stream

Purpose of gas reinjection
High pressure gas reinjection is used for many producing fields:
Provides pressure maintenance
Improves recovery of oil
Provides storage and swing capacity
Different form for application:
Non-miscible injection
Miscible injection
Tertier injection after water flooding
Injection in gas/condensate fields

Gas Properties and Reservoir Considerations
For Improved Recovery
Reservoir geology and configuration
Compatability with reservoir fluid
Miscibility
Injectivity
Theft Zones(High permeability layers, Hetrogeniety)
For Storage
Reservoir geology and configuration
Available volume
Injectivity
Reservoir pressure
Leakage
Normally not a problem
Strict rules for well plugging before abandonment

Injection facilities
Standard high pressure compressors are applied driven by gas turbines or electrical motors
Gas have to be cleaned and conditioned before compressed and reinjected into the reservoir
Injection wells normally cheaper than production wells

The economics of gas reinjection
Gas reinjection has to compete with other alternatives for utilization.
For IOR purposes there are always great uncertainties regarding efficiency and added recovery of oil
For storage purposes better utilization of transportation systems and improved delivery efficency is the main economical driver.
Some gas will be used as fuel(2-3%) to reinject and 15-25% of gas reinjected will be left in the reservoir.

Reservoir Management
System for Management and Monitoring is requiered.
Most companies have established monitoring program for each field based on geological models, petrophysical properties of the reservoir and reservoir simulations.
Reservoir behaviour evaluated on regular basis by flow measurement and well testing.
In some instances tracers are used to understand flow regimes in the reservoir

The Norwegian Case Carbon Limit, Amsterdam, 03.12.08

The Norwegian Continental Shelf Carbon Limit, Amsterdam, 03.12.08

Petroleum production Carbon Limit, Amsterdam, 03.12.08 2012

Gas Balance - Norwegian Continental Shelf Carbon Limit, Amsterdam, 03.12.08

Prudent Extraction Carbon Limit, Amsterdam, 03.12.08 Petroleum Act: § 4-1 “ Production of petroleum shall take place in such manner that as much as possible of the petroleum in place in each individual petroleum deposit, or in several deposits in combination, will be produced. The production shall take place in accordance with prudent technical and sound economic principles and in such a manner that waste of petroleum or reservoir energy is avoided. The licensee shall carry out continuous evaluation of production strategy and technical solutions and shall take the necessary measures in order to achieve this.”

Gas flaring and venting regulations
Petroleum Act: § 4-4
“ Flaring in excess of the quantities needed for normal operational safety shall not be allowed unless approved by the Ministry”:
Associated gas utilisation required to get authority approval of Plan for Development and Operation
Annual gas flaring permits
Avoid waste of petroleum and reservoir energy
Cold venting is not in accordance with the principle of environmentally prudent petroleum production
CO 2 -tax charged on all fuel and flare consumed and vented gas (~USD 0.1 per Sm 3 gas)

Reservoir Management
Production reg. - Section 27
“ The licensee shall continually monitor the deposit during production, including pressure and flow conditions, produced or injected volumes per well, zone and reservoir, the composition of components of petroleum etc.
The total monthly production and injection volumes of the field shall be apportioned to each individual well on a monthly basis according to recognized norm.”

Gas (and WAG) injection on NSC – a success ! Carbon Limit, Amsterdam, 03.12.08 EOR effect to date estimated to be 180-220 million Sm3 extra oil and condensate 1984: gas into Ekofisk and Statfjord

Gas injection cases
Togi
Statfjord
Grane
Carbon Limit, Amsterdam, 03.12.08 Oseberg Troll

Area consideration (Tampen)
Fields evaluated for external injection:
Snorre
Sygna
Statfjord Nord
Vigdis
Possible source for gas:
Gullfaks

CO2-injection
Associated CO 2 - removed from produced gas and injected into storage reservoar
Snøhvit
Sleipner
CO 2 from gas power plant
Test Centre Mongstad
NPD is currently working on a project to identify the best storage reservoar for a planned full-scale gas power plant in Norway

CO2 injection and storage at Sleipner 06/07/09 Sleipner A Sleipner T Utsira Formation Heimdal Formation Production and Injection wells CO 2 CO 2 Injection well 1000m 2000m 2500m 0 500m 1500m 1000m 0 500m 1500m

Gas reinjection related to CDM Carbon Limit, Amsterdam, 03.12.08

Reinjection schemes
Reinjection for IOR
Reinjection for storage

Reinjection will reduce CO2 emission
Reinjection for improved oil recovery(IOR)
Major reduction in CO2 emission until injected gas is reproduced and utilized
Some emission due to power generation for injection compressors
Reinjection for storage
Reduction in CO2 emission for as long as the gas is being stored assuming no leakage
Necessary precautions to avoid leakage has to be made as well as establishment of system for leakage monitoring.

Injection Monitoring
Program for Reservoir Management
Petroleum producing countries have rules and regulations for proper depletion and requirments for reservoir management
In general most companies will have program established for reservoir monitoring
Behaviour of gas injected can be traced using well testing and reservoir simulations
Gas resirculation will be discovered through GOR measurement
Possible to establish monitoring program that controls reproduction of injected gas.

Additionality
IOR from gas injection has in the long run proved more economical than expected
Yet, in a project perspective the IOR-effect may be too risky for investment purposes
CDM may be a good solution for projects to reduce flaring on fields in production.
Flaring restriction should however be handled at planning stage as a requirement to the company developing the field.

Closing remarks
Gas reinjection is a well known method for storing of gas instead of flaring
Gas reinjection will in most cases improve oil recovery if applied in a right way
Calculation and accounting of gas injected and stored should be possible through proper reservoir monitoring
Considering the huge amount of gas currently being flared, gas reinjection is a fast and valuable alternative to avoid flaring and thereby reduce CO2 emission

Ekofisk – Future CO2 Storage?

The World Carbon Limit, Amsterdam, 03.12.08

The difference between natural gas(CH4+) and CO2
CH4+
Rich in energy
Easy to produce
Easy to store
High value on storage
CO2
Low in energy
Difficult to extract
Easy to store
Low value on storage

Gas reinjection and flaring reduction Norway's experience - Steinar Nja (Norway Petroleum Directorate)

by Esther Petrilli-Massey on Jan 15, 2009

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Gas reinjection and flaring reduction Norway’s experience - Steinar Nja (Norway Petroleum Directorate) Presentation Transcript

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