NuVista Energy Ltd. Provides Operational Update

CALGARY, ALBERTA--(Marketwire - Dec. 21, 2011) - NuVista Energy Ltd. ("NuVista") (TSX:NVA) is pleased to provide an operational update for its W5 Spirit River/Notikewin and W6 Wapiti plays.

W5 Spirit River/Notikewin

We continue to experience positive results from the W5 Spirit River/Notikewin drilling program and the successful advancement of this play. The 13-24-45-9 W5M Spirit River horizontal well in the liquids-rich Alder Flats area was previously announced (November 10, 2011) with a gross test rate of 16 MMcf/d at 1300 psi surface flowing pressure. This well has now been tied-in and is on production at a restricted rate of 10 MMcf/d and approximately 300 Bbls/d of associated natural gas liquids (NGL's). The 13-13-45-9 W5M Spirit River horizontal well that was waiting on completion at the time of the Q3 press release has now been completed using multi-stage fracture techniques and has tested at a rate of 7.5 MMcf/d and 650 psi, with approximately 225 Bbls/d of NGL's over a 36 hour period. This well was also brought on production this week. Debottlenecking of pipeline and processing facilities in the Alder Flats area is well underway and production rate restrictions are expected to be removed within the next few weeks for these wells. The latest Alder Flats Spirit River horizontal well at 5-24-45-9 W5M has now been drilled and is waiting on completion. We continue to broaden the geographic footprint of new prospects in this area to bolster the inventory towards our target of 75 locations. Results from this program continue to meet or exceed type curve expectations. Production from the new 2011 horizontal multi-frac wells in this play is averaging 22 MMcf/d raw gross with approximately 650 Bbls/d of NGL's (87% WI) today, up from nil in Q1 2011.

W6 Wapiti Montney and Falher

In the W6 Wapiti area, we continue to advance our five well Montney drilling program announced earlier in 2011. We have been studying the previously announced completion results for the first well in the program at 9-1-68-8 W6M in our North Block of Montney landholdings, and intervention activities on this well are planned in the first quarter of 2012. The second well at 2-1-66-6 W6M in our South Block of Montney landholdings has been drilled successfully and on budget. This well has now been completed and flow tested with very favorable results, confirming our expectations for liquids-rich gas in the large South Block of NuVista's Wapiti Montney landholdings. Flowback from this well was restricted as planned to 4.5 MMcf/d at a surface casing pressure of 3100 psi for much of the multi-day test period in order to manage water and condensate handling logistics and comply with flare permit limitations. The well was temporarily increased to a rate of 10 MMcf/d and the corresponding casing pressure remained high at 2450 - 2600 psi, favorably indicating minimal drawdown at this rate. Early liquids data averaged approximately 50 barrels of free condensate (C5+) per MMcf of raw gas production. This represents a C5+ flow of 500 Bbls/d at 10 MMcf/d. H₂S levels were low as expected at 0.6% - 0.8%. Raw gas sampling and analysis continues, but all early indications indicate that this well should at least equal the liquids ratios seen in the North Block, meaning approximately 80 - 100 barrels of C2+ per MMcf of raw gas flow (when access to a deep cut facility is available), or 800 - 1,000 Bbls/d of C2+ when initial well flow rates are 10 MMcf/d of raw gas. We remain very encouraged from these preliminary results indicating that this well has the potential to meet or exceed our type curve expectations for the area. The well is being tied-in and is expected to be brought on production in the first quarter of 2012. With the significant step-out in distance between our South Block lands and the more drilled North Block area, this is a pivotal step in proving the liquids-rich productive capability of our large South Block Montney landholdings. NuVista holds a total of 155 net sections of land in the North and South Montney blocks, at close to 100% working interest.

The third well in the program, in our North Block, is currently drilling on schedule within the Montney reservoir with rig release anticipated in early January 2012, with the multi-stage fracture completion to follow. It is anticipated that the fourth well in the Montney program will follow shortly thereafter. Depending on spring breakup timing, we expect to have drilled all five of the five well program by early Q2 2012, and to have completion results on four, with the fifth well completion likely after spring breakup.

The Wapiti Montney compression and dehydration project, which is being executed to service North Block production is proceeding on budget and schedule for startup in early or late Q2 2012 with the dependency mainly being on spring break-up timing.

The previously announced Wapiti Falher well which tested at 14.9 MMcf/d at 2600 psi surface flowing pressure has now been tied-in and is on production at a restricted gross rate of 3 MMcf/d. Infrastructure debottlenecking and compression installation are ongoing to bring the well to its full potential on or near the end of Q1 2012.

NuVista production as we exit 2011 is averaging the midpoint of our previously articulated guidance range for the first half of 2012, 24,500 - 25,500 Boe/d, with more behind-pipe gas and liquids to be added as the debottlenecking projects outlined above are brought to fruition in the coming weeks and months. As our drilling programs in the W6 Montney and Falher and the W5 Spirit River/Notikewin plays continue, we expect to provide the next operational update in conjunction with our year end 2011 financial and operating results press release in early March 2012.

ADVISORY REGARDING OIL AND GAS INFORMATION

This news release contains the terms barrels of oil equivalent ("Boe") and thousand cubic feet equivalent ("Mcfe"). Natural gas is converted to a Boe using six thousand cubic feet of gas to one barrel of oil. In certain circumstances natural gas liquid volumes have been converted to a Mcfe on the basis of one barrel of natural gas liquids to six thousand cubic feet of gas. Boes and Mcfes may be misleading, particularly if used in isolation. The foregoing conversion ratios are based on an energy equivalency conversion method primarily applicable at the burner tip and does not represent a value equivalency at the wellhead.

ADVISORY REGARDING FORWARD-LOOKING INFORMATION AND STATEMENTS

This press release contains forward-looking statements and forward-looking information (collectively, "forward-looking statements") within the meaning of applicable securities laws. The use of any of the words "will", "expects", "believe", "plans", "potential" and similar expressions are intended to identify forward-looking statements. More particularly and without limitation, this press release contains forward looking statements, including management's assessment of: NuVista's future strategy, plans, opportunities and operations; forecast production; production mix; drilling, development, completion and tie-in plans and results; NuVista's planned capital budget and plans regarding infrastructure improvements and/or expansions, the timing thereof and the results therefrom; the anticipated potential of NuVista's asset base. This press release also contains test results for various wells. Actual production could differ materially from these results.

By their nature, forward-looking statements are based upon certain assumptions and are subject to numerous risks and uncertainties, some of which are beyond NuVista's control, including the impact of general economic conditions, industry conditions, current and future commodity prices, currency and interest rates, anticipated production rates, borrowing, operating and other costs and funds from operations, the timing, allocation and amount of capital expenditures and the results therefrom, anticipated reserves and the imprecision of reserve estimates, the performance of existing and future wells, the success obtained in drilling new wells, the sufficiency of budgeted capital expenditures in carrying out planned activities, competition from other industry participants, availability of qualified personnel or services and drilling and related equipment, stock market volatility, effects of regulation by governmental agencies including changes in environmental regulations, tax laws and royalties; the ability to access sufficient capital from internal sources and bank and equity markets; and including, without limitation, those risks considered under "Risk Factors" in our Annual Information Form. Readers are cautioned that the assumptions used in the preparation of such information, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, undue reliance should not be placed on forward-looking statements. NuVista's actual results, performance or achievement could differ materially from those expressed in, or implied by, these forward-looking statements, or if any of them do so, what benefits NuVista will derive therefrom. NuVista disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.