NEWSROOM

    TORONTO, July 27 /CNW/ - Pacific Rubiales Energy Corp. (TSX: PRE)
announced today the discovery of oil at its I-9 ST-2 well, drilled on Prospect
"I" at the Quifa Block (refer to press release dated July 2, 2009), located in
the Llanos Basin of Colombia.
    The I-9 ST-2 well found the top of the basal sandstones at a depth of
2,038 feet true vertical depth sub-sea (TVDSS) (3,162 feet measured depth
(MD)) and the oil-water contact at 2,081 feet TVDSS (3,222 feet MD), resulting
in a vertical oil column of 41 feet gross at the well. Preliminary
petrophysical evaluation of the data at the well indicates a net pay zone of
18 feet with porosities over 30%. The well was drilled at an angle of
43degrees and reached a final depth of 3,563 feet MD in the Quifa Block. The
company is presently planning to test the well with perforations at
3175'-3190' (15 feet) and complete it as a producer. The results of this well,
located on Prospect "I", confirm the continuation of the Rubiales field into
the Quifa Block to the southwest.
    Ronald Pantin, the company's Chief Executive Officer, stated: "This well
not only extends the known reservoir but also builds on our knowledge of the
area. We are very pleased with the results which strengthen our confidence in
the production potential of the other prospects in Quifa."

    Quifa Block exploration plans 2009The company is now preparing the logistics to drill four additional wells
    on the Quifa Block for the remainder of 2009:

    -   Quifa-9, an exploratory well on Prospect "D" by the end of August;
    -   Quifa-8, an appraisal well for Quifa 5 on Prospect "E" during
        September;
    -   Quifa-7, an exploratory well on Prospect "H" during October; and
    -   Quifa-6, an exploratory well on Prospect "A" during November.(Please refer to detailed map of Prospects in the Quifa Block within the
company's Exploration Plan (July 2009) located on the company's web site:
    http://pacificrubiales.com/investor_information/investor_presentations)

    The Quifa Block is an exploratory block that almost completely surrounds
the Rubiales Field in which the company holds a 60% working 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 six additional prospects that
have been identified with the interpretation of the recently completed seismic
campaign.

    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 34 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