NEWSROOM

    TORONTO, April 23 /CNW/ - Pacific Rubiales Energy Corp. (TSX: PRE)
announced today that it has discovered oil in the Mirla Negra region with one
well in the Arrendajo Block, located within the Llanos Basin and another in
the Buganviles Block, located within the Upper Magdalena Basin. The company
has also provided an exploration update on the Guasimo and Quifa Blocks.
    Ronald Pantin, the company's Chief Executive Officer, commented: "We are
pleased with the exploration discoveries made on three blocks belonging to our
subsidiary Kappa Resources. The discoveries confirm the potential to grow the
light oil production segment of our business and as a result of these
discoveries, we have three new oil fields to develop."Mirla Negra 1 - Arrendajo Block
    -------------------------------The Mirla Negra 1 well was drilled to a total depth of 6,237 feet
measured depth (MD) in the Arrendajo Block, located in the Llanos Basin of
Colombia. The well reached the top of the reservoir, the Carbonera C-5
Formation at 5,493 feet MD or 4,937 feet true vertical depth sub-sea level.
The reservoir consists of 66 feet MD of net sandstones and the petrophysical
analysis shows 6 feet of net pay with an average porosity of 21%. Well tests
were carried on Carbonera C-5 along the perforated interval 5,506 - 5,510 feet
MD. Early production tests have shown a daily rate of 130 barrels of oil at
34.5 API gravity with a 69% water cut. The Arrendajo Block is an exploratory
contract where Pacific Rubiales holds a 32.5 % working interest.Delta 1 - Buganviles
    --------------------The exploratory well Delta-1 was drilled in the Buganviles Block, located
in the Upper Magdalena Valley in central Colombia. The well reached the top of
the Caballos formation at 5,976 feet and the basement at a depth 6,297 feet.
This reservoir interval consists of 321 feet of limestone and the
petrophysical analysis shows 20 feet MD of net pay within the 312 feet MD of
the upper limestone section. Average porosities range from 3 to 6%; however,
due to the presence of fractures the porosity could potentially double that
amount. The preliminary P50 area estimated for this structure, based on the
post-drill seismic interpretation, is 1,420 acres. The well was completed
perforating a 46 feet interval and preliminary tests have shown a daily
production of 48 barrels per day at 34.5 API gravity oil. The Buganviles Block
is an exploratory contract with Ecopetrol in which Pacific Rubiales holds a
49.375% working interest.Exploration update
    ------------------The exploratory well Lisa-1 located within the Guasimo Block was
completed in January 2009 within the Guadalupe Formation in porous
porcellanites. The petrophysical evaluation of the well indicated a net
reservoir thickness of 150 feet and 24 feet pay, with an average combined
matrix and fracture porosity of 16%. The well initially produced batches of
24.5 API gravity oil and after a fracture work-over the well is producing
today 42 barrels of oil per day. The company has a 100% working interest in
the Guasimo Block.
    As part of the exploration program for 2009, the company is planning to
spud the Quifa-6 exploration well on Prospect "I" located in the Quifa Block
at the end of May 2009. Subsequent to drilling Quifa-6, the company will drill
an appraisal well on the Quifa block to evaluate the extension of the
discovery made on Prospect D in 2008 (Well Rub-147).

    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 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 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 March
31, 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