Advantage Announces Significant Increase in Reserves & Contingent Resources and Updates Guidance & Strategic Alternatives

 Advantage Announces Significant Increase in Reserves & Contingent Resources
            and Updates Guidance & Strategic Alternatives Process

PR Newswire

CALGARY, May 21, 2013

(TSX: AAV, NYSE: AAV)

(All reserve and resource volumes are "working interest" and "sales" except
where otherwise indicated)

CALGARY, May 21, 2013 /PRNewswire/ -

Highlights:

  *Total Petroleum Initially in Place ("TPIIP") at Glacier increased to 16.0
    Tcf

  *2P Reserves plus 2C Contingent Resources increased to 5.9 Tcfe

       *2C Contingent Resources increased to 4.20 Tcfe; 72% of which is
         contained in the liquids rich Middle Montney intervals that are
         approximately 150 meters thick

       *2P Reserves grew to 1.61 Tcfe which includes 11 million barrels of
         NGLs

  *Our Special Committee's financial advisors will immediately commence a
    broad marketing effort to solicit interest in a sale of the Corporation or
    other strategic transaction to maximize value for all shareholders. The
    updated independent Reserve Report reflecting wells drilled and completed
    since December 31, 2012 and the updated independent Glacier Resource
    Assessment Report will be available to interested parties in the virtual
    data room.

  *The management of Advantage Oil & Gas Ltd. has prepared the following
    production model which shows that our Glacier property can support a
    production plateau of 580 mmcf/d for a period of approximately 18 years
    based on the total 2P Reserves and 2C Contingent Resources.

                 http://files.newswire.ca/1241/AAV-Chart.pdf

Contingent Resource Assessment

(Summary tables and resources definitions are included in Appendix A & C)

Advantage Oil &  Gas Ltd.  ("Advantage" or  the "Corporation")  is pleased  to 
announce its updated  Reserve Report and  updated Glacier Contingent  Resource 
Assessment which were prepared by Sproule Associates Ltd. ("Sproule") with  an 
effective  date  of  March   31,  2013  (see   page  5  "Independent   Reserve 
Evaluator").  Changes  in  Contingent  Resources  are  compared  against  our 
previous Glacier Contingent Resource Assessment dated February 29, 2012  which 
includes reserves from December 31, 2011. The terms 'interval' and 'layer'  in 
this release and in Sproule's reports have the same meaning.

  *Gross TPIIP at Glacier increased by 69% to 17.06 Tcf. On a working
    interest basis, TPIIP is 16.03 Tcf which contains 337.1 million barrels of
    NGLs.

  *2P Reserves plus 2C Contingent Resources increased by 123% to 5.89 Tcfe.
    The natural gas component increased by 107% to 5.17 Tcf with NGLs growing
    by 336% to 121.3 million barrels.

  *2C Contingent Resources increased by 138% to 4.2 Tcfe. The largest
    component of this increase occurred in the liquids rich Middle Montney
    intervals which grew by 204% to 2.9 Tcfe.

  *Sproule assumed a Montney development plan based on 20 horizontal wells
    per section (4 horizontal wells in each of the five 50 meter Montney
    intervals) for their evaluation at Glacier. Based on this plan, the total
    number of gross horizontal well locations remaining on the Glacier land
    block is 1,550.

  *Advantage conducted an extensive Core Study and a Completion Study during
    2012 on the Montney formation in the Glacier area. The results of these
    studies were pivotal in advancing our understanding of the geological and
    petrophysical properties of the various intervals that comprise the
    Montney formation at Glacier.

  *As a result of our Completion study, we employed revised completion and
    fracture stimulation techniques on 4 horizontal wells distributed across
    our land block. The results demonstrated commercial production rates
    between 3 to 5 mmcf/d of liquids rich natural gas in the Middle Montney
    intervals. The results of our Core Study determined that traditional well
    log analysis has limited effectiveness in measuring porosity in the
    Montney formation. Sproule utilized the Core study results to recalibrate
    70 open hole well logs at Glacier resulting in a significant increase in
    the net pay calculation included in determining TPIIP.
  *The combined results of the Completion and Core studies resulted in a 69%
    increase in TPIIP as illustrated in the table below:


        Comparison of Glacier TPIIP Estimates
            February 29,2012  March 31,2013     
  Montney                                      %
Interval^(1) (Tcf gross raw)  (Tcf gross raw) Increase
    1 UM           2.97            3.38         14%
    2 MM           2.26            3.25         44%
    3 MM           0.93            2.60         180%
    4 MM           0.83            2.51         202%
    5 LM           2.85            3.82         34%
    6 LM           0.23            1.51         557%
   Total          10.07            17.06        69%

Note: ^ (1) UM - Upper Montney, MM - Middle Montney, LM - Lower Montney

  *The changes in 2P Reserves plus 2C Contingent Resource by Montney interval
    are illustrated in the table below:

Comparison of Glacier 2P Reserves plus 2C Contingent Resources^(1) % Increase
                                                                     in Gas
                                                                   Equivalent
           February 29, 2012 Report      March 31, 2013 Report        
Montney   Natural    NGLs      Gas     Natural NGLs^(2)    Gas         
Interval    Gas    (mbbls)  Equivalent   Gas   (mbbls)  Equivalent
           (Bcf)              (Bcfe)    (Bcf)             (Bcfe)
1 UM       1,115      0       1,115     1,226     0       1,226       10%
2 MM        346     14,593     433      1,118   48,188    1,407       225%
3 MM        165     5,628      199       828    35,824    1,043       424%
4 MM        112     4,941      142       674    29,191     849        498%
5 LM        751     2,692      767      1,319   8,141     1,368       78%
Total      2,490    27,854    2,657     5,166  121,344    5,894       123%

^(1)2P reserves are 'technical reserves' which include cumulative  production 
of approximately  100 bcf.  No 2P  Reserves or  2C Contingent  Resources  were 
assigned to the 6^th Lower Montney interval.

^(2)Sproule assigned an average C3+ NGLs yield of 43 bbls/mmcf sales gas  for 
the Middle Montney intervals based on  a shallow cut extraction process.  The 
Lower Montney was assigned an average C3+ NGLs yield of 7 bbls/mmcf sales gas.

  *The changes in 2C Contingent Resource by Montney interval are illustrated
    in the table below:

       Comparison of Glacier 2C Contingent Resources^(1)         % Increase
                                                                 (Decrease)
         February 29, 2012 Report     March 31, 2013 Report         
Montney  Natural  NGLs      Gas     Natural NGLs ^(1)    Gas         
Interval   Gas   (mbbls) Equivalent   Gas    (mbbls)  Equivalent
          (Bcf)            (Bcfe)    (Bcf)              (Bcfe)
1 UM       276      -       276       188       -        188       (32%)
2 MM       332   31,686     522       982    42,574     1,237       137%
3 MM       162    7,473     207       749    32,467      944        356%
4 MM       112   13,314     192       674    29,191      849        342%
5 LM       512    4,277     538       947     6,041      983        83%
Total     1,394  56,750    1,735     3,540   110,274    4,201       142%

^(1)No ^ 2C  Contingent Resources  were assigned  to the  6^th Lower  Montney 
interval.

^(2)Sproule assigned an average C3+ NGLs yield of 43 bbls/mmcf sales gas  for 
the Middle Montney intervals based on  a shallow cut extraction process.  The 
Lower Montney was assigned an average C3+ NGLs yield of 7 bbls/mmcf sales gas.

Updated Advantage Reserves Report (as of March 31, 2013)
(Summary tables and definitions are included in Appendix B & C)
The updated reserves report  includes only Advantage's 'stand-alone'  reserves 
and excludes the assets of Longview  Oil Corp. and also excludes the  non-core 
assets that  were  sold to  Questfire  Energy Corp.  on  April 30,  2013.  The 
reserves at Glacier constitute 99.7% of Advantage's total reserves. Changes in
reserves are compared against our December  31, 2012 year end Sproule  Reserve 
Report

  *Glacier's 2P Reserves increased by 13.8% to 1.61 Tcfe. 2P natural gas
    reserves increased by 10.4% to 1.54 Tcf and 2P NGLs increased by 318% to
    11.03 million bbls.

  *The increase in 2P Reserves resulted primarily from the addition of future
    undeveloped locations in intervals 2 and 3 of the Middle Montney. These
    future locations were assigned to sections immediately adjacent to the
    Middle Montney wells that were completed and tested in the first quarter
    of 2013.

  *As of March 31, 2013, Sproule has assigned reserves to only 25% of the
    total Montney drilling locations at Glacier.

  *Reserves were assigned to only 8% of the total drilling locations in the
    Middle Montney formation. The Middle Montney includes C3+ NGLs of
    approximately 43 bbls/mmcf of sales gas which significantly enhances the
    value of this horizon. Further drilling is required to delineate the
    Middle Montney both laterally and vertically with the potential for
    approximately 1,000 wells across the entire land block.

  *The Lower Montney is present over our entire land block and is confirmed
    by vertical well control at Glacier and vertical and horizontal wells that
    offset our land block. Reserves have been assigned to only 27% of the
    total Lower Montney drilling locations which leaves significant potential
    for future reserves growth with additional delineation and development
    drilling.

  *The Net Present Value of the Sproule 2P Glacier reserves increased by 22%
    to $1.72 billion as at March 31, 2013 (at a 10% pre-tax discount).

  *Advantage's Net Asset Value increased by 24% to $9.82 per share as at
    March 31, 2013 (at a 10% pre-tax discount) based on 2P Reserves with no
    value included for Contingent Resources.

Glacier Phase VI Development Plan - Capital Budget and Updated Guidance

  *The Board of Directors of Advantage has approved a capital and operating
    budget for our Phase VI Glacier development program for the 12 months
    ending March 31, 2014. The Budget will be funded through cash flow,
    available credit facilities and cash generated from Advantage's
    investments which includes dividends from the 21.1 million shares in
    Longview Oil Corp, interest and principal payments on the $33 million
    Questfire Debentures and 1.5 million Questfire B shares.

  *Advantage has an active hedging program designed to stabilize cash flow
    and fund capital expenditures. We have hedged 35 mmcf/d at $3.48/mcf from
    April 2013 to March 2014.

  *Our Phase VI Glacier development program is designed to increase
    production to 135 mmcf/d by the end of Q1 2014. The following table
    outlines the key budget parameters:

                                                       
                            April to                    
                             December         January to      12 Months ending
                             2013^(1)         March 2014         March 2014
                                                              
Production (boe/d)                           21,400 -    
                          17,800 - 18,200       21,800        18,500 - 18,900
Exit Production Rate                                     
(boe/d)                          -                 -             22,500^(2)
Royalty Rate (%)               4.9%            4.5%             4.8%
Operating Costs ($/boe)        $2.42           $1.79           $2.24
Capital Expenditure ($                                   
million)^(3)                   $106               $64               $170

Note: ^(1)  Includes the operating and financial results for the month of
             April 2013 from non-core assets sold to Questfire Energy Corp.
             on April 30, 2013.
      ^(2)  ^Exit Production rate equivalent to 135 mmcf/d.
       ^(3) Capital expenditures are budgeted to be incurred as follows: Q2
             2013 $3.1 million, Q3 2013 $41.4 million, Q4 2013 $61.4 million,
            Q1 2014 $63.9 million. Capital expenditures includes a total of
             approximately $9.6 million for plant costs, capitalized G&A and
             other minor upgrades.

  *The capital program will include a total of 22 wells which consist of 7
    Upper Montney wells, 3 Middle Montney wells and 12 Lower Montney wells.
    The majority of the wells in this program will be drilled with longer
    lateral lengths and include an average of 17 fracs per well compared to
    our historic average of 13 fracs per well. This will reduce the total
    number of wells required to achieve our 135 mmcf/d production rate as we
    estimate the average 30 day initial production rate per well will increase
    from our historic type curve of 5 mmcf/d to 7.2 mmcf/d. The average per
    well cost is estimated to be $7.5 million which is higher than our
    historic average due to the additional number of fracs, longer length
    wells, utilization of open hole packer systems and higher strength casing
    to facilitate higher frac pump rates. The 22 wells will be drilled on 8
    pads of which 6 pads will be newly constructed.

  *We have secured three drilling rigs and are planning to commence drilling
    operations in July 2013 with initial completion operations planned to
    commence in September 2013. A fourth drilling rig may be employed subject
    to weather conditions.

  *Strategic Alternatives Process Update

  *The updated independent Reserve Report and Glacier Resource Assessment
    Report will be included in the virtual data room. As envisaged by the
    Corporation's February 26, 2013 press release, the Special Committee's
    financial advisors, FirstEnergy Capital Corp. and RBC Capital Markets will
    immediately commence a broad marketing effort to solicit interest in a
    sale of the Corporation or other strategic transaction to maximize value
    for all shareholders.

  *To that end, the financial advisors have posted their initial marketing
    materials on their respective websites and have begun to contact
    prospective parties.

  *The Corporation cautions that there can be no assurance that this process
    will result in an acceptable transaction.

Independent Reserve Evaluator

  *Sproule Associates Ltd. ("Sproule") was engaged as an independent
    qualified reserve evaluator to evaluate the Corporation's reserves and
    resources as of March 31, 2013 in accordance with National Instrument
    51-101 ("NI 51-101") and the Canadian Oil and Gas Evaluation Handbook
    ("COGE Handbook").

Appendix A - Glacier Contingent & Prospective Resource Assessment
Advantage engaged our independent qualified reserves evaluator Sproule to
update the resource analysis at Glacier as of March 31, 2013 in accordance to
the COGEH resource definitions that are consistent with the standards of NI
51-101. The estimates of reserves and resources for individual properties may
not reflect the same confidence level as estimates of reserves and future net
revenue for all properties, due to the effects of aggregation.

The following three tables summarize the results of Sproule's updated resource
assessment:

Resource Categories (AAV working interest, best estimate, Raw) ^(1)   Tcf
Total Petroleum Initially In Place (TPIIP)                          16.03
Discovered Petroleum Initially in Place (DPIIP) ^(2)                13.98
Undiscovered Petroleum Initially in Place (UPIIP) ^(3)               2.05

(1)  TPIIP, DPIIP and UPIIP have been estimated using a zero percent porosity
     cut-off (sandstone log scale). The Montney formation is approximately
     300 meters thick at Glacier. Sproule's analysis utilized 6 potential
     layers consisting of 1 layer in the Upper Montney, 3 layers in the Middle
     Montney and 2 layers in the Lower Montney. With the exception of the
     lowest layer in the Lower Montney, all other layers exist across the
     entire Glacier land block.
(2)  There is no certainty that it will be commercially viable to produce any
     portion of the resources.
(3) There is no certainty that any portion of the resources will be
     discovered. If discovered, there is no certainty that it will be
     commercially viable to produce any portion of the resources.

Reserves & Contingent Resources (AAV working          Low      Best     High
interest, Sales) ^(1) (2)                           Estimate Estimate Estimate
Natural Gas                                                            
Reserves (Tcf) ^(3) (4)                              1.027    1.626    1.870
Contingent Resources (Tcf) ^(5) (7)                  2.316    3.540    4.898
Total Reserves Plus Contingent Resources (Tcf)       3.343    5.166    6.768
Natural Gas Liquids ^(6)                                               
Reserves (mbbls)                                     5,949    11,071   12,732
Contingent Resources (mbbls) ^ (7)                   72,472  110,274  152,013
Total Reserves Plus Contingent Resources (mbbls)     78,421  121,345  164,745
Total Natural Gas and Natural Gas Liquids (Tcfe)     3.814    5.894    7.757



(1)   All DPIIP other than cumulative production (as at March 31, 2013
       cumulative production from Glacier was 99.94 Bcf of natural gas),
      reserves and Contingent Resources have been categorized as
       unrecoverable. The economic status of the Contingent Resources have
       not been determined.
(2)   Recoverable gas volumes were estimated using a 4 well per section
       development in each of the 6 layers within the Montney formation at
      Glacier. Recovery factors were assigned to each layer based on the
       performance of existing wells in the layer or in similar layers. All of
       the natural gas that is considered recoverable from layer 6 is
       currently classified as prospective.
(3)  Reserves have only been assigned to Layer 1 (Upper Montney), Layers 2 &
       3 (Middle Montney) and Layer 5 (Lower Montney).
(4)   For reserves, the Low Estimate are proved reserves, the Best Estimate
      are 2P reserves and the High Estimate are 2P plus possible reserves.
       Cumulative production of 99.94 Bcf from Glacier has been added to the
       reserves volumes when associated with a Contingent Resource volume.
(5)   Contingent Resources are assigned to all five layers except the sixth
       layer of the Lower Montney. Contingent Resources for each section and
      layer were assigned if there was a sustained gas test within 2 miles of
       the section, otherwise, the resource was classified as prospective
       undiscovered resources.
(6)   Liquid yields are unique to each layer and were estimated based on the
      gas composition of gas samples combined with any free liquids obtained
       from well production tests in each layer.
(7)    The contingencies Sproule identified to convert Contingent Resource
      into reserves are specific to each layer and generally include the
       following:

1.Development maturity including the number of sustained well tests and the
    amount of production information. Sproule indicates that very few
    sections in Layers 2 and 3 (Middle Montney) have reserves assigned;
    however, there are sufficient tests spread geographically across the lands
    to classify the bulk of the sections as Contingent Resources. No reserves
    have been assigned to Layer 4 (Middle Montney); however, there have been
    sufficient testing of a few wells located very low in Layer 3 and spread
    geographically across the lands to classify many sections as contingent in
    Layer 4.
2.The lack of infrastructure to facilitate full development in the short
    term including the required processing facilities to extract NGLs in
    certain Montney layers.
3.Economic contingencies dictating a slower pace of development with current
    low gas prices in sections that are farther from existing gas gathering
    infrastructure and farther from existing tests.

Prospective Resources (AAV working interest, Sales)   Low      Best     High
^(1) (2) (3)                                        Estimate Estimate Estimate
Natural Gas (Tcf)                                    0.342    0.556    0.776
Natural Gas Liquids (mbbls)                          7,381    11,691   16,274
Total Natural Gas & Natural Gas Liquids (Tcfe)       0.386    0.626    0.874

(1) All UPIIP other than prospective resources have been categorized as
     unrecoverable
(2) Recoverable gas volumes were estimated using a 4 well per section
     development in each of the 6 layers within the Montney formation at
     Glacier. Recovery factors were assigned to each layer based on the
     performance of existing wells in the layer or in similar layers.
(3)  Prospective resources were assigned to Layers 2, 3 and 4 of the Middle
     Montney and Layer 6 of the Lower Montney if there were no sustained gas
     tests within 3 miles of the section.

Prospective  resources  account  for  only  9.6%  of  the  estimated  ultimate 
recoverable resources in the 2C best  estimate case and demonstrates that  the 
vast majority  of  the Montney  formation  at Glacier  has  been shown  to  be 
productive.

Appendix B - Advantage Corporate Reserve Summary
Advantage engaged our independent qualified reserves evaluator ("Sproule") to
update the reserves analysis for the Company (the "Sproule Report") as at
March 31, 2013 in accordance with NI 51-101 ("NI 51-101") and the COGE
Handbook.

The Sproule  Report  includes  only  Advantage's  "stand-alone"  reserves  and 
excludes the assets  in Longview Oil  Corp and the  non-core assets that  were 
sold to Questfire  Energy Corp. on  April 30, 2013.  Reserves and  production 
information included herein  is stated  on a Gross  Working Interest  Reserves 
basis  unless  noted  otherwise.  This  summary  contains  several  cautionary 
statements that are specifically required by NI 51-101.

Gross Working Interest Reserves (Working Interest only)

Summary as at March 31, 2013

                                     Natural                     Oil
                     Light &     Heavy        Gas      Natural
                    Medium      Oil   Liquids          Gas  Equivalent
                         Oil
                   (mbbl)   (mbbl)   (mbbl)      (mmcf)      (mboe)
Proved                                                       
Developed               25        -      259      179,421      30,188
Producing
Developed                -        -      283       27,997       4,949
Non-producing
Undeveloped             -        -     5,452     741,815     129,088
Total Proved           25        -     5,994     949,234     164,225
Probable                4        -     5,139     596,758     104,603
Total Proved +           29       -    11,133   1,545,992     268,828
Probable

Present Value of Future Net Revenue using Sproule price and cost forecasts
^(1)(2)(3)
($000)

                                   Before Income Taxes Discounted          
                                                                 at
                               0%                   10%                 15%
Proved                                                                    
Developed Producing      $710,513             $391,814            $326,099
Developed Non-producing   122,586               71,051              58,607
Undeveloped             2,447,260              638,511             355,780
Total Proved            3,280,359            1,101,376             740,486
Probable                3,264,855              647,168             383,465
Total Proved + Probable 6,545,214            1,748,544           1,123,951

^(1) Advantage's crude oil, natural gas and natural gas liquid reserves were
     evaluated using Sproule's product price forecast effective March 31, 2013
     prior to the provision for income taxes, interests, debt services charges
     and general and administrative expenses. It should not be assumed that
     the discounted future revenue estimated by Sproule represents the fair
     market value of the reserves.
^(2) Assumes that development of each property will occur, without regard to
     the likely availability to the Company of funding required for that
     development.
^(3) Future development capital increase from $1.53 billion to $1.87 billion
     is included in the updated Reserve Report.

Net Asset Value using Sproule price and cost forecasts (Before Income Taxes)

The following net asset value ("NAV") table shows what is normally referred to
as a  "produce-out" NAV  calculation  under which  the  current value  of  the 
Company's reserves would be produced at forecast future prices and costs.  The 
value is a  snapshot in  time and is  based on  various assumptions  including 
commodity prices and foreign exchange rates that vary over time.

                                           Before Income Taxes Discounted at
($million, except per Share amounts)             0%        10%       15%
Net asset value per Share ^ (1) - December                       
31, 2012                                       $34.58      $9.26      $5.80
Present value proved and probable reserves    $6,545    $1,749    $1,124
Undeveloped acreage and seismic ^ (2)              21         21         21
Working capital (deficit) and other             (49)      (49)      (49)
Convertible debentures                          (86)      (86)      (86)
Bank debt                                      (125)     (125)     (125)
Questfire Debentures                              33        33        33
Questfire B Shares ^(3)                           5          5         5
Longview shares at market value^(3)              106       106      106
Net asset value - March 31, 2013              $6,450     1,654     1,029
Net asset value per Share ^(1) - March 31,                       
2013                                           $38.30      $9.82      $6.11

^(1) ^Based on 168.4 million common shares outstanding at March 31, 2013, and
     168.4 million common shares outstanding at December 31, 2012.
^(2) ^Internal estimate
^(3) ^1.5 million Questfire shares @ 3.40/share, Longview 21.1 million shares
     @$5.02/share

Sproule Price Forecasts

The present value of future net revenue at March 31, 2013 was based upon crude
oil and natural gas  pricing assumptions prepared  by Sproule effective  March 
31, 2013. These  forecasts are  adjusted for  reserve quality,  transportation 
charges and  the  provision  of  any applicable  sales  contracts.  The  price 
assumptions used over the next seven years are summarized in the table below:

            WTI     Edmonton  Alberta AECO-C     Henry Hub   Exchange
                           Light
      Crude Oil     Crude Oil    Natural Gas   Natural Gas       Rate
Year  ($US/bbl)   ($Cdn/bbl)   ($Cdn/mmbtu)  ($US/mmbtu)  ($US/$Cdn)
2013      92.85        87.92           3.52          3.87      0.999
2014      90.51        85.58           3.80          4.14      0.999
2015      87.69        87.75           3.95          4.30      0.999
2016      93.22        93.30           4.66          5.00      0.999
2017      96.96        97.03           5.32          5.66      0.999
2018      98.41        98.49           5.40          5.74      0.999
2019      99.89        99.96           5.49          5.83      0.999

Appendix C — Reserve and Resource Definitions

Reserves are estimated remaining quantities of oil and natural gas and related
substances anticipated to be recoverable from known accumulations, as of a
given date, based on the analysis of drilling, geological, geophysical and
engineering data; the use of established technology; and specified economic
conditions, which are generally accepted as being reasonable. Reserves are
classified according to the degree of certainty associated with the estimates
as follows:

    Proved Reserves are those reserves that can be estimated with a high
  degree of certainty to be recoverable. It is likely that the actual
    remaining quantities recovered will exceed the estimated proved reserves.
  
    Probable Reserves are those additional reserves that are less certain to
  be recovered than proved reserves. It is equally likely that the actual
    remaining quantities recovered will be greater or less than the sum of the
    estimated proved plus probable reserves.
  
    Possible Reserves are those additional reserves that are less certain to
  be recovered than probable reserves. It is unlikely that the actual
    remaining quantities recovered will exceed the sum of the estimated proved
    plus probable plus possible reserves.

Resources encompasses all petroleum quantities that originally existed on or
within the earth's crust in naturally occurring accumulations, including
Discovered and Undiscovered (recoverable and unrecoverable) plus quantities
already produced. "Total resources" is equivalent to "Total Petroleum
Initially-In-Place". Resources are classified in the following categories:

    Total Petroleum Initially-In-Place ("TPIIP") is that quantity of petroleum
    that is estimated to exist originally in naturally occurring
  accumulations. It includes that quantity of petroleum that is estimated,
    as of a given date, to be contained in known accumulations, prior to
    production, plus those estimated quantities in accumulations yet to be
    discovered.
  
    Discovered Petroleum Initially-In-Place ("DPIIP") is that quantity of
    petroleum that is estimated, as of a given date, to be contained in known
  accumulations prior to production. The recoverable portion of discovered
    petroleum initially in place includes production, reserves, and Contingent
    Resources; the remainder is unrecoverable.
  
    Contingent Resources are those quantities of petroleum estimated, as of a
    given date, to be potentially recoverable from known accumulations using
  established technology or technology under development but which are not
    currently considered to be commercially recoverable due to one or more
    contingencies.
  
    Undiscovered Petroleum Initially-In-Place ("UPIIP") is that quantity of
    petroleum that is estimated, on a given date, to be contained in
  accumulations yet to be discovered. The recoverable portion of
    undiscovered petroleum initially in place is referred to as "prospective
    resources" and the remainder as "unrecoverable."
  
    Prospective Resources are those quantities of petroleum estimated, as of a
  given date, to be potentially recoverable from undiscovered accumulations
    by application of future development projects.
  
    Unrecoverable is that portion of DPIIP and UPIIP quantities which is
    estimated, as of a given date, not to be recoverable by future development
    projects. A portion of these quantities may become recoverable in the
  future as commercial circumstances change or technological developments
    occur; the remaining portion may never be recovered due to the
    physical/chemical constraints represented by subsurface interaction of
    fluids and reservoir rocks.

Uncertainty Ranges are described by the Canadian Oil and Gas Evaluation
Handbook as low, best, and high estimates for reserves and resources as
follows:

    Low Estimate: This is considered to be a conservative estimate of the
    quantity that will actually be recovered. It is likely that the actual
  remaining quantities recovered will exceed the low estimate. If
    probabilistic methods are used, there should be at least a 90 percent
    probability (P90) that the quantities actually recovered will equal or
    exceed the low estimate.
    Best Estimate: This is considered to be the best estimate of the quantity
    that will actually be recovered. It is equally likely that the actual
  remaining quantities recovered will be greater or less than the best
    estimate. If probabilistic methods are used, there should be at least a 50
    percent probability (P50) that the quantities actually recovered will
    equal or exceed the best estimate.
    High Estimate: This is considered to be an optimistic estimate of the
    quantity that will actually be recovered. It is unlikely that the actual
  remaining quantities recovered will exceed the high estimate. If
    probabilistic methods are used, there should be at least a 10 percent
    probability (P10) that the quantities actually recovered will equal or
    exceed the high estimate.

Advisory

The  information  in  this  press  release  contains  certain  forward-looking 
statements,  including  within  the  meaning  of  the  United  States  Private 
Securities Litigation Reform Act  of 1995. These  statements relate to  future 
events or  our future  intentions or  performance. All  statements other  than 
statements   of   historical   fact   may   be   forward-looking   statements. 
Forward-looking statements are often, but not always, identified by the use of
words  such   as  "seek",   "anticipate",  "plan",   "continue",   "estimate", 
"demonstrate", "expect",  "may",  "will", "project",  "predict",  "potential", 
"targeting", "intend",  "could",  "might", "should",  "believe",  "would"  and 
similar expressions and  include statements  relating to,  among other  things 
that Advantage's Special Committee's financial advisors will commence a  broad 
marketing effort  to solicit  a sale  of the  Corporation or  other  strategic 
transaction to maximize value  for all shareholders, management's  expectation 
of increasing production and reserves  at Glacier, future development  capital 
associated with the reserves on the Glacier property, certain future  expected 
production levels and the expected percentage of such production that will  be 
hedged, expected future capital expenditures, the expected number of wells  to 
be drilled in the Upper Montney, Middle Montney and Lower Montney, the lateral
lengths and number of fracs per  well, the expected average costs of  drilling 
such wells and the expected productivity  of such wells, the expectation  that 
less wells will be required to achieve a 135 mmcf/d production rate and timing
for commencement of drilling. These statements involve substantial known  and 
unknown risks  and  uncertainties, certain  of  which are  beyond  Advantage's 
control, including:  the  impact  of  general  economic  conditions;  industry 
conditions; changes  in laws  and regulations  including the  adoption of  new 
environmental laws and regulations and changes in how they are interpreted and
enforced; fluctuations in commodity prices  and foreign exchange and  interest 
rates; stock market  volatility and  market valuations;  volatility in  market 
prices for oil and  natural gas; liabilities inherent  in oil and natural  gas 
operations; uncertainties  associated  with  estimating oil  and  natural  gas 
reserves; competition  for,  among  other  things,  capital,  acquisitions  of 
reserves, undeveloped lands  and skilled personnel;  incorrect assessments  of 
the value of acquisitions; changes in income  tax laws or changes in tax  laws 
and incentive programs relating to the oil and gas industry and income trusts;
geological, technical, drilling and processing problems and other difficulties
in  producing  petroleum  reserves;   and  obtaining  required  approvals   of 
regulatory authorities. The production model presented herein for our  Glacier 
property has  been presented  to  demonstrate the  potential for  the  Glacier 
property. It is not intended to represent an estimate of future production  as 
future productions levels  will depend  on a number  of factors  and does  not 
reflect Advantage's current  plans for development  of the Glacier  property. 
Advantage's actual decisions, activities, results, performance or  achievement 
could  differ  materially  from  those  expressed  in,  or  implied  by,  such 
forward-looking statements and, accordingly, no  assurances can be given  that 
any of the events anticipated by the forward-looking statements will transpire
or occur or, if any of them do, what benefits that Advantage will derive  from 
them. Except  as  required  by  law, Advantage  undertakes  no  obligation  to 
publicly update or revise any forward-looking statements. For additional risk
factors in respect of Advantage and  its business, please refer to its  Annual 
Information Form  dated  March  23,  2012  which  is  available  on  SEDAR  at 
www.sedar.com and www.advantageog.com.

References in this press release to  initial test production rates are  useful 
in confirming  the  presence  of  hydrocarbons, however  such  rates  are  not 
determinative of the rates  at which such wells  will commence production  and 
decline thereafter. Such  rates are  not necessarily indicative  of long  term 
performance or of ultimate recovery. While encouraging, readers are  cautioned 
not to place reliance  on such rates in  calculating the aggregate  production 
for Advantage.

Throughout this press release the terms boe (barrels of oil equivalent),  bcfe 
(billions of cubic feet of gas equivalent) and Tcfe (trillion of cubic feet of
gas equivalent) are used. Such terms  may be misleading, particularly if  used 
in isolation. The conversion ratio used herein of six thousand cubic feet  per 
barrel (6 mcf:  1 bbl) of  natural gas to  barrels of oil  equivalent and  the 
conversion ratio used herein of 1 barrel per six thousand cubic feet (1 bbl: 6
mcf) of  barrels of  oil  to natural  gas equivalent  is  based on  an  energy 
equivalency conversion method primarily applicable at the burner tip and  does 
not represent a value equivalency at the wellhead. Given that the value  ratio 
based on  the  current price  of  crude oil  as  compared to  natural  gas  is 
significantly different  from  the  energy equivalency  of  6:1,  utilizing  a 
conversion on a 6:1 basis may be misleading as an indication of value.

The following abbreviations used in this press release, including in the
appendices hereto, have the meanings set forth below:

bbls     barrels                     mcf      thousand cubic feet
bbls/d   barrels per day             mmcf     million cubic feet
                                   mmcf/d   million cubic feet per day
mbbls    thousand barrels            bcf      billion cubic feet
boe      barrels of oil equivalent   bcfe     billion cubic feet of
           of natural gas, on the                   natural gas equivalent on
           basis of 1 barrel of oil                 the basis of 1 barrel of
           or NGLs for 6 thousand                   oil or NGLs to 6 thousand
           cubic feet of natural gas                cubic feet of natural gas
mboe     thousands of barrels of     tcf      trillion cubic feet
           oil equivalent
boe/d    barrels of oil equivalent   tcfe     trillion cubic feet of
           per day                                  natural gas equivalent on
                                                    the basis of 1 barrel of
                                                    oil to 6 thousand cubic
                                                    feet of natural gas
2P       proved plus probable        2C       best estimate contingent
           reserves                                 resources
NGLs     natural gas liquids                 
                                           

Where any disclosure of reserves data and resources is made in this press
release that does not reflect all reserves of Advantage, the reader should
note that the estimates of reserves, future net revenue and resources for
individual properties or groups of properties may not reflect the same
confidence level as estimates of reserves and future net revenue for all
properties, due to the effects of aggregation.

SOURCE Advantage Oil & Gas Ltd.

PDF available at:
http://stream1.newswire.ca/media/2013/05/21/20130521_C8478_DOC_EN_26922.pdf

Contact:

Investor Relations
Toll free: 1-866-393-0393

Advantage Oil & Gas Ltd.
700, 400 -3^rd Avenue SW
Calgary, Alberta
T2P 4H2
Phone: (403) 718-8000
Fax: (403) 718-8300
Web Site:www.advantageog.com
E-mail:ir@advantageog.com