NEWSROOM

    TORONTO, July 31 /CNW/ - Pacific Rubiales Energy Corp. (TSX: PEG)
announced today that its fully owned subsidiary, Meta Petroleum, has executed
an agreement with Ecopetrol S.A., the national oil company of Colombia, to
jointly develop the Alicante Block in the Llanos Orientales Basin of Colombia.
    Under this agreement Ecopetrol will farm out 55% of its working interest
rights in the Alicante Block to Pacific Rubiales. The Alicante Block, which is
located 20 kilometres east of the City of Villavicencio was awarded by the
National Hydrocarbons Agency of Colombia (ANH) to Ecopetrol in 2006. Alicante
is also located next to the Apiay Block, close to existing infrastructure.
    Working commitments under this agreement include seismic acquisition
during the third quarter of 2008 and drilling one exploratory well in the
second half of 2009.
    The block has a total area of 38,684 hectares and is part of the wider
strategy that the two companies are executing for the development of heavy
crudes in Colombia. This agreement requires the formal approval of the ANH.
    Ronald Pantin, CEO of Pacific Rubiales Energy, stated "We are delighted
to develop the Alicante Block with Ecopetrol. This agreement reinforces our
commitment to the development of heavy crude oil potential in the Colombian
Llanos."

    Pacific Rubiales, a Canadian-based company and producer of natural gas
and heavy crude oil, owns 100 percent of Meta Petroleum Limited, a Colombian
oil operator which operates the Rubiales and Piriri oil fields 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
21,000 barrels of oil equivalent per day, with working interests in the
Rubiales, Piriri and Quifa concessions and the Caguan, Dindal, Rio Seco, Puli
B, La Creciente, Moriche, Guama, Arauca, Tacacho and Jagueyes blocks in
Colombia and blocks 135, 137 and 138 in Peru.

    All monetary amounts in U.S. dollars unless otherwise stated. This news
release contains certain "forward-looking statements" and "forward-looking
information" under applicable Canadian securities laws concerning the
business, operations and financial performance and condition of Pacific
Rubiales Energy Corp. Forward-looking statements and forward-looking
information include, but are not limited to, statements with respect to
estimated production and reserve life of the various oil and gas projects of
Pacific Rubiales; the estimation of oil and gas reserves; the realization of
oil and gas reserve estimates; the timing and amount of estimated future
production; costs of production; success of exploration activities; and
currency exchange rate fluctuations. Except for statements of historical fact
relating to the companies, certain information contained herein constitutes
forward-looking statements. Forward-looking statements are frequently
characterized by words such as "plan," "expect," "project," "intend,"
"believe," "anticipate", "estimate" and other similar words, or statements
that certain events or conditions "may" or "will" occur. Forward-looking
statements are based on the opinions and estimates of management at the date
the statements are made, and are based on a number of assumptions and subject
to a variety of risks and uncertainties and other factors that could cause
actual events or results to differ materially from those projected in the
forward-looking statements. Many of these assumptions are based on factors and
events that are not within the control of Pacific Rubiales and there is no
assurance they will prove to be correct. Factors that could cause actual
results to vary materially from results anticipated by such forward-looking
statements include changes in market conditions, risks relating to
international operations, fluctuating oil and gas prices and currency exchange
rates, changes in project parameters, the possibility of project cost overruns
or unanticipated costs and expenses, labour disputes and other risks of the
oil and gas industry, failure of plant, equipment or processes to operate as
anticipated, the business of Petro Rubiales and Pacific Stratus not being
integrated successfully or such integration proving more difficult, time
consuming or costly than expected as well as those risk factors discussed or
referred to in the annual Management's Discussion and Analysis and Annual
Information Form for Pacific Rubiales filed with the securities regulatory
authorities in all provinces of Canada and available at www.sedar.com.
Although Pacific Rubiales has attempted to identify important factors that
could cause actual actions, events or results to differ materially from those
described in forward-looking statements, there may be other factors that cause
actions, events or results not to be anticipated, estimated or intended. There
can be no assurance that forward-looking statements will prove to be accurate,
as actual results and future events could differ materially from those
anticipated in such statements. Pacific Rubiales undertakes no obligation to
update forward-looking statements if circumstances or management's estimates
or opinions should change except as required by applicable securities laws.
The reader is cautioned not to place undue reliance on forward-looking
statements. Statements concerning oil and gas reserve estimates may also be
deemed to constitute forward-looking statements to the extent they involve
estimates of the oil and gas that will be encountered if the property is
developed.
    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.

    %SEDAR: 00007953E