NEWSROOM

    TORONTO, Aug. 26 /CNW/ - Pacific Rubiales Energy Corp. (TSX: PRE)
announced today the discovery of oil at its Quifa-8 well drilled as an
appraisal well on Prospect "E" at the Quifa Block, located in the Llanos Basin
of Colombia.
    The well found the top of the Basal Sandstones at a depth of 2,263 feet
True Vertical Depth Sub-Sea (TVDSS) (2,955 feet measured depth (MD)). The
preliminary petrophysical evaluation shows a gross sand interval of 116 feet
with a net pay zone of 49.5 feet comprising two reservoir sandstones. The
first interval (2955'- 2999' MD) extends the accumulation of the Quifa-5 field
to the west, with a net-oil pay of 33 feet and average porosity of 31%. A
second, deeper sand interval (3048'-3071'MD) with a petrophysical evaluation
shows a net-oil pay of 16.5 feet with 32% average porosity. This deeper
interval effectively confirms a new discovery within the basal sands. Both
intervals show oil-water contacts at 2,999 feet and 3,071 feet MD,
respectively. The company is presently planning to test both reservoirs, and
complete the well as a vertical oil producer.
    The Quifa-8 well is located 4.2 kilometres southwest of the Quifa-5 well
drilled in November 2008, which showed 33 feet of net pay.
    The Quifa Block is an exploratory block that almost completely surrounds
the Rubiales Field in which the company holds a 60% interest in association
with Ecopetrol S.A. (40%). The Quifa contract gives Pacific Rubiales the right
to develop any discovery until 2031. This block is three times larger than the
Rubiales field and has seven additional prospects that have been identified
with the interpretation of the recently completed seismic campaign.Exploration Update
    ------------------The company converted the Arauca Technical Evaluation Agreement (TEA)
into a new Exploration & Production (E&P) contract with the Agencia Nacional
de Hidrocraburos (ANH). This contract contemplates a 24-month first
exploratory phase with work commitments of two exploratory wells at an
estimated total cost of US$9,000,000. The contract incorporates an area of
173,584 hectares with an estimated resource potential of 297.7 mmbls,
distributed among 16 prospects and leads that have been identified based on
the reprocessing of 2,000 kms of 2D seismic.
    Following an optimization and re-evaluation of its exploration portfolio,
the company has decided to relinquish the Alhucema and Jagueyes E&P contracts
executed with the ANH.
    The Alhucema block is located in the Middle Magdalena Basin, and was
acquired by the company in the acquisition of Kappa Resources in the second
half of 2008. The company decided to relinquish the E&P contract, and not to
continue with phase 4 of the contract, after interpreting new seismic data
acquired in 2009 and re-evaluating the prospectivity and risk of the block.
The company's working interest in the block was 50%, with the remaining 50%
held by Alhucema Resources Corp.
    The Jagueyes block is located in the northern part of the Llanos Basin
and was acquired in the second half of 2007 through an ANH bidding round.
After the processing and evaluation of 112 km(2) of 3D seismic, acquired as
part of phase 1 of the contract, the company decided not to proceed with the
next phase, since no prospective exploratory plays could be identified. The
company's working interest in this block was 100%.
    Relinquishing these properties is part of the company's strategy to
optimize its exploratory efforts and focus its resources on blocks with the
best prospectivity.

    Pacific Rubiales, a Canadian-based company and producer of natural gas
and heavy crude oil, owns 100 percent of Meta Petroleum Corp., a Colombian oil
operator which operates the Quifa block in the Llanos Basin in association
with Ecopetrol S.A., the Colombian national oil company. The company is
focused on identifying opportunities primarily within the eastern Llanos Basin
of Colombia as well as in other areas in Colombia and northern Peru. Pacific
Rubiales has a current net production of approximately 34,000 barrels of oil
equivalent per day, with working interests in 32 blocks in Colombia and Peru.

    Boe may be misleading, particularly if used in isolation. A boe
conversion ratio of 6 mcf: 1 bbl is based on an energy equivalency conversion
method primarily applicable at the burner tip and does not represent a value
equivalency at the wellhead.

    Cautionary Note Concerning Forward-Looking Statements

    This press release contains forward-looking statements. All statements,
other than statements of historical fact, that address activities, events or
developments that the company believes, expects or anticipates will or may
occur in the future (including, without limitation, statements regarding
estimates and/or assumptions in respect of production, revenue, cash flow and
costs, reserve and resource estimates, potential resources and reserves and
the company's exploration and development plans and objectives) are
forward-looking statements. These forward-looking statements reflect the
current expectations or beliefs of the company based on information currently
available to the company. Forward-looking statements are subject to a number
of risks and uncertainties that may cause the actual results of the company to
differ materially from those discussed in the forward-looking statements, and
even if such actual results are realized or substantially realized, there can
be no assurance that they will have the expected consequences to, or effects
on the company. Factors that could cause actual results or events to differ
materially from current expectations include, among other things: uncertainty
of estimates of capital and operating costs, production estimates and
estimated economic return; the possibility that actual circumstances will
differ from the estimates and assumptions; failure to establish estimated
resources or reserves; fluctuations in petroleum prices and currency exchange
rates; inflation; changes in equity markets; political developments in
Colombia or Peru; changes to regulations affecting the company's activities;
uncertainties relating to the availability and costs of financing needed in
the future; the uncertainties involved in interpreting drilling results and
other geological data; and the other risks disclosed under the heading "Risk
Factors" and elsewhere in the company's annual information form dated April 1,
2009 filed on SEDAR at www.sedar.com. Any forward-looking statement speaks
only as of the date on which it is made and, except as may be required by
applicable securities laws, the company disclaims any intent or obligation to
update any forward-looking statement, whether as a result of new information,
future events or results or otherwise. Although the company believes that the
assumptions inherent in the forward-looking statements are reasonable,
forward-looking statements are not guarantees of future performance and
accordingly undue reliance should not be put on such statements due to the
inherent uncertainty therein.

    %SEDAR: 00007953E