NEWSROOM

TORONTO, April 26 /CNW/ - Pacific Rubiales Energy Corp. (TSX: PRE; BVC: PREC) announced today the final results of the first phase of its exploration campaign from late 2007 through to April 2010, on its Quifa and Rubiales Blocks, located in the Llanos Basin, Colombia. These results have led to a declaration of commerciality for the Quifa southwest area and the Rubiales southwest area, an important event for the company as it has focused significant effort and capital to bring these areas into production.

Mr. Ronald Pantin, Chief Executive Officer of Pacific Rubiales, commented: "The closing of this first phase is a key milestone in our strategy to continuously grow our resources, prove new reserves and rapidly bring new areas into our existing production infrastructure. The success of the exploration campaign within Quifa in particular, leading to over 40,000 ha of declared commerciality, is also very significant since it demonstrates the long term viability of the Rubiales region and the Llanos Basin. I commend our technical team for their commitment to this campaign, their execution ability and the results that we have seen thus far."

The Quifa and Rubiales exploration campaign to date has included the acquisition of 323 km of 2D seismic profiles and the drilling of a total of 35 wells on both blocks: 23 wells on the Quifa Block - consisting of 7 exploratory, 6 stratigraphic and 10 appraisal wells; and 12 wells on the Rubiales Block, consisting of 3 exploratory and 9 appraisal wells. In total the exploration campaign had a success rate of 83%.

As a result of this extensive campaign, a number of oil discoveries and incorporations have been carried out. Discoveries in Prospects "D", "E" and "H" in the Quifa Block incorporated a total of 83 mmbo of certified 2P (P1 + P2) gross reserves, while in the Rubiales Block, the discoveries in the northwest and southwest areas added 80 mmbo of certified 2P (P1+P2) gross reserves, for a total of 163 mmbo 2P reserves incorporated during the exploration campaign in both blocks. These reserves were certified by Petrotech Engineering under NI 51-101 (refer to press release dated March 15, 2010). These discoveries allowed the Company to request from Ecopetrol the approval of commerciality for the Quifa southwest area and the Rubiales southwest area (please refer to the company's investor presentation for a detailed map of these areas, located on the company's website at www.pacificrubiales.com). The commerciality for Quifa southwest was approved by Ecopetrol, on April 19th, 2010. The commerciality for the area of northwest Rubiales has been submitted to Ecopetrol and is pending for approval.

In addition, in the northern Quifa area, 3 wells, including one exploratory and two stratigraphic wells drilled on Prospects "A", "F" and "Q", confirmed the presence of a hydrocarbon column on the top of the basal sandstones incorporating a total of 251 mmbo of certified gross resources. The following table summarizes the distribution of the certified resources as reported by Petrotech Engineering:

Estimate                                     Low        Best        High
    Prospect A                                   ---        ----        ----
    ----------
    Area, acres                                6,741       7,931       9,121
    Petroleum Originally in Place, Mbbl      163,594     213,848     282,814
    Recovery factor, %                            18          18          18
    Recoverable Oil Resources, Mbbl           29,447      38,493      50,906

    Prospect F
    ----------
    Area, acres                               12,037      14,161      16,285
    Petroleum Originally in Place, Mbbl      658,062     860,212   1,137,630
    Recovery factor, %                            18          18          18
    Recoverable Oil Resources, Mbbl          118,451     154,838     204,773

    Prospect Q
    ----------
    Area, acres                                6,694       7,875       9,056
    Petroleum Originally in Place, Mbbl      245,391     320,773     442,222
    Recovery factor, %                            18          18          18
    Recoverable Oil Resources, Mbbl           44,170      57,739      76,360

    Total Recoverable Oil Resources, Mbbl    197,068     251,070     332,039

The company is now preparing a request for an additional exploration period in Quifa, to continue the exploration campaign on the prospects that found oil to the northern part of the block. The second phase of the exploration campaign will include the drilling of appraisal wells as well as shooting more 2D seismic in the Quifa block. A total of $43.4 million has been budgeted for Quifa exploration in 2010, in addition to $65.5 million for the construction of production facilities.

QUIFA BLOCK EXPLORATION TO DATE

The exploration campaign in the Quifa block started in 2007 with the acquisition of 323 km of 2D seismic information. The seismic surveys optimized the subsurface image and the geologic interpretation of the block contributing to a redefinition of its exploration prospectivity. The results of the seismic interpretation allowed the company to identify 18 exploratory prospects on the Quifa block, named with the letters "A" through "R". Based on this evaluation, the Company drilled the Rub-147 exploratory well on Prospect "D" in the Rubiales area and the Quifa-5 exploratory well on Prospect "E" during the last quarter of 2008. Both wells resulted in oil discoveries.

As a result of these two discoveries, the company developed an aggressive drilling campaign to evaluate the prospects already identified. 22 additional wells, including six exploratory, ten appraisal and six stratigraphic wells were then drilled between the second half of 2009 and the first quarter of 2010. The exploratory wells Quifa-7, Quifa-9 and Quifa-I9-ST2, drilled on Prospects "H", "D" and "I", respectively, found oil on the Basal Sandstones and incorporated new reserves to the southwestern region of the Quifa block. The Quifa-6 exploratory well and the Quifa-22X, Quifa-24X and Quifa-26X stratigraphic wells also found oil in the same stratigraphic unit and confirmed the presence of hydrocarbons in the northern region of the Quifa block.

The appraisal drilling campaign included the Quifa-13 well on Prospect "D", Quifa-8, Quifa-12, Quifa-14, Quifa-17 and Quifa-18 wells on Prospect "E" and the Quifa-10, Quifa-11, Quifa-31 and Quifa-32 wells on Prospect "H". These appraisal wells successfully confirmed the extension of the discovered reservoirs made on Prospects "D", "E", "H" and "I" in southwest Quifa.

Also, the extensive production tests carried out in these wells confirmed the production potential of this area, similar to that of the adjacent Rubiales field. The exploration campaign on southwest Quifa incorporated 83 mmbo of certified proved and probable (P1+P2) gross reserves. Additionally, the Quifa-15 and Quifa-16 exploratory wells, drilled in Prospects "B" and "C" , and the Quifa-23X, Quifa-33X and Quifa-34X stratigraphic wells, drilled in Prospects "G", "C" and "M", located to the eastern and northern border of the block respectively, were unsuccessful and subsequently abandoned.

The petrophysical evaluation of all the wells indicated a net pay zone varying from 16 to 49.5 feet, averaging 24 feet, and with average porosities of 31%. The wells in southwest Quifa (Prospects "D", "E", and "H") were completed as producers, and the initial production tests indicated an average daily rate of 300 bopd of 13.4 degree API oil, slightly higher than the 12.5 degree API produced at the Rubiales oil field. A summary of the results of the 23 drilled wells in Quifa is shown below:

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                                   Top of
                                    basal
                                    sands     OWC                     Average
                                   (TVDSS) (TVDSS)  Net   Average       Water
    Prospect  Wells  Classification (feet)  (feet)  Pay  Porosity  Saturation
    -------------------------------------------------------------------------
    A      QUIFA 6   Exploratory    -2732   -2758    16      0.30         0.5
    -------------------------------------------------------------------------
    B      QUIFA 15  Exploratory    -2063       -   Dry      0.31           0
    -------------------------------------------------------------------------
           QUIFA 16  Exploratory    -2009       -   Dry      0.30           1
    C     -------------------------------------------------------------------
           QUIFA 33  Stratigraphic  -1855       -   Dry      0.29           1
    -------------------------------------------------------------------------
    D      QUIFA 9   Exploratory    -2304   -2333    17      0.32        0.53
          -------------------------------------------------------------------
           QUIFA 13  Appraisal      -2300   -2330    19      0.29        0.57
    -------------------------------------------------------------------------
           QUIFA 5   Exploratory    -2248   -2310    33      0.31        0.41
          -------------------------------------------------------------------
           QUIFA 8   Appraisal      -2263   -2379  49.5      0.32        0.47
          -------------------------------------------------------------------
           QUIFA 12  Appraisal      -2255   -2310    40      0.33        0.32
    E     -------------------------------------------------------------------
           QUIFA 14  Appraisal      -2245   -2315    33      0.32        0.54
          -------------------------------------------------------------------
           QUIFA 17  Appraisal      -2269   -2300    18      0.31         0.5
          -------------------------------------------------------------------
           QUIFA 18  Appraisal      -2257   -2315    49      0.33        0.41
    -------------------------------------------------------------------------
    F      QUIFA 26X Stratigraphic  -2594   -2659    41      0.29        0.46
    -------------------------------------------------------------------------
    G      QUIFA 23  Stratigraphic  -2786       -   Dry      0.28           1
    -------------------------------------------------------------------------
           QUIFA 7   Exploratory    -2206   -2245    24      0.30        0.46
          -------------------------------------------------------------------
           QUIFA 10  Appraisal      -2229   -2273    20      0.32        0.48
          -------------------------------------------------------------------
    H      QUIFA 11  Appraisal      -2207   -2243    12      0.32        0.46
          -------------------------------------------------------------------
           QUIFA 31  Appraisal      -2194   -2230    26      0.29        0.43
          -------------------------------------------------------------------
           QUIFA 32  Appraisal      -2188   -2234    25      0.32        0.49
    -------------------------------------------------------------------------
    I      I-09st2   Exploratory    -2038   -2081    22      0.30        0.62
    -------------------------------------------------------------------------
    L      QUIFA 22X Stratigraphic  -2459   -2465     6      0.30        0.62
    -------------------------------------------------------------------------
    M      QUIFA 34X Stratigraphic  -2178       -   Dry      0.30           1
    -------------------------------------------------------------------------
    Q      QUIFA 24X Stratigraphic  -2665   -2712    22      0.32        0.49
    -------------------------------------------------------------------------

The extended production tests of 13 wells in the southwest part of Quifa supported the formal request for the commercial development for the area. This request was submitted on February 9, 2010, and has now been approved by Ecopetrol.

COMMERCIALITY ZONE AND QUIFA CONTRACT

The commerciality zone has an approximate area of 40,000 ha, and a development plan is being developed in order to reach the target of 30,000 bopd by the end of 2010 and 60,000 bopd by the end of 2011 for the whole of the Quifa block. The Quifa Contract, which continues until 2031, establishes that capital costs and operational expenses must be borne 70% by the company and 30% by Ecopetrol, and distribution of production after payment of royalties will be 60% to the company and 40% to Ecopetrol.

RUBIALES BLOCK

After the successful discovery results of the Rub-147 exploratory well, exploration activity was focused on an appraisal drilling campaign to the southwest and northwest borders of the Rubiales field, which included a total of 10 appraisal wells. The Rub-150, Rub-220, Rub-221, Rub-222 and Rub-224 wells confirmed the extension of the reservoir to the southwest of the Rubiales Block, while the Rub-251, Rub-366, Rub-357 and Rub-372 wells supported the continuity of Quifa Prospect "D" into the Rub-147 well discovery to the northeast. The well Rub-148 extended the reservoir to the east of the Rubiales-Piriri field and the well Rub-310, drilled in the northeastern part of the Rubiales-Piriri field, resulted dry. Extended production tests of 10 wells supported the request to extend the commercial area of the Rubiales field to the southwest, incorporating 22.2 mmbo of gross oil reserves for the southwest area. The results of the drilled wells in the northwest part of the field incorporated 57.8 mmbo of gross oil reserves, for a total of 80.0 mmbo of gross oil reserves incorporated for the field. The commerciality of the northwestern part of Rubiales has been submitted to Ecopetrol for approval.

A summary of the drilling results for the 12 Rubiales wells is shown below:

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                                   Top of
                                    basal
                                    sands     OWC                     Average
                                   (TVDSS) (TVDSS)  Net   Average       Water
    Prospect  Wells  Classification (feet)  (feet)  Pay  Porosity  Saturation
    -------------------------------------------------------------------------
    C         Rub-310  Exploratory  -1977       -   Dry      0.29        0.46
    -------------------------------------------------------------------------
              RUB-147  Exploratory  -2291   -2347    35      0.30        0.47
             ----------------------------------------------------------------
              RUB-251  Appraisal    -2271   -2371    31      0.30        0.49
             ----------------------------------------------------------------
    D         RUB-357  Appraisal    -2311   -2374    40      0.31        0.38
             ----------------------------------------------------------------
              RUB-366  Appraisal    -2301   -2337    31      0.30        0.35
             ----------------------------------------------------------------
              RUB-372  Appraisal    -2348   -2402     8      0.31        0.68
    -------------------------------------------------------------------------
              Rub-150  Appraisal    -2026   -2092    23      0.32        0.54
             ----------------------------------------------------------------
              Rub-220  Appraisal    -2160   -2214    38      0.31        0.24
    Rubiales ----------------------------------------------------------------
    Southwest Rub-221  Appraisal    -2129   -2194    20      0.30         0.6
             ----------------------------------------------------------------
              Rub-222  Appraisal    -2079   -2142    33      0.28        0.39
             ----------------------------------------------------------------
              Rub-224  Appraisal    -2057   -2112    22      0.30        0.54
    -------------------------------------------------------------------------
    Rubiales  Rub-148  Exploratory  -1842   -1873    24      0.31        0.37
    East
    -------------------------------------------------------------------------

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/Piriri and Quifa Block in the Llanos Basin in association with Ecopetrol S.A., the Colombian national oil company. Also, through its affiliate Pacific Stratus Energy Corp., 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 over 55,000 barrels of oil equivalent per day (after royalties), with working interests in 32 blocks in Colombia and Peru.

Information in this press release expressed in barrels of oil equivalent (boes) is derived by converting natural gas to oil in the ratio of six thousand cubic feet (mcf) of natural gas to one barrel (bbl) of oil. 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 12, 2010 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.