Pacific Rubiales Announces La Creciente-E-1 (LCE-1) Well Reaches Target Zone
May 23, 2008

    TORONTO, May 23 /CNW/ - Pacific Rubiales Energy Corp. (TSX: PEG)
announced today that the La Creciente-E-1 well, located at Prospect "E" in the
Lower Magdalena Basin in Colombia, has reached a Measured Depth (MD) of
11,939 feet and has encountered the top of the Ciénaga de Oro Formation at
11,478 feet MD and the basement at 11,828 feet MD. The Logging While Drilling
resistivity and Gamma ray logs indicate that the target Ciénaga de Oro
Formation consists of shales without reservoir characteristics. The Company
also ran a vertical seismic profile (VSP) in order to understand the
high-amplitude seismic events in the prospect area.
    Data gathered thus far suggests that the structure at prospect E was a
paleo-high during the Ciénaga de Oro deposition and the reservoir sandstones
did not reach the crest of the structure. The acquisition and interpretation
of the VSP will help calibrate the seismic reflections with the well's
stratigraphy and perhaps help locate where these sandstones pinched-out and if
they are within the structure's closing contours and reachable with a deviated
hole from this location.
    The pinch-outs of the Ciénaga de Oro sandstones at prospect E are
independent of the sandstones' manifestation or its presence in the rest of
the company's prospects. As a result, the company's evaluation of the
exploration potential for prospects B, C, F, G, H, I and J at La Creciente
remains unchanged. The company is continuing its review of the distribution of
the sandstones at these prospects.
    While the data from the VSP is being interpreted, the Rig Saxon 133 will
be moved to complete the drilling of LCA-2 st well that was suspended pending
the approval to drill the lower section of the hole with oil-based mud. The
Ministry of the Environment recently granted this approval, allowing the
resumption of drilling activities at this well.

    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.

    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

For further information:
For further information: Jose Francisco Arata, President or Ronald
Pantin, Chief Executive Officer, (416) 362-7735