Exhibit 99.1

Operations

North Sea

U.S.

North Sea

Our three producing fields in the U.K. — Alba, Bittern and Enoch — had combined sales totaling 1,053 MBOE for the nine months ended September 30, 2011.

U.S.

Our strategy for our U.S. operations has been to employ a measured approach that seeks to balance U.S. natural gas prices with drilling costs. We plan to continue this disciplined approach, which includes:

2012 Capital Budget

We expect that our total capital expenditure budget for 2012 will be between $175 million and $200 million. We expect to spend approximately $150 million to $175 million of the total 2012 budget in the U.K., primarily on the advancement of our development projects. Capital expenditures for Bacchus will be our initial priority, as we plan to reach first production during the first quarter. Once the three Bacchus wells begin producing and we have consummated the COP Acquisition, we expect to earmark a substantial portion of the cash flows from these assets to complete the necessary development program for the Greater Rochelle area to reach first production in the fourth quarter of 2012. We expect to spend the remainder of our 2012 capital budget in the U.S. to evaluate our Heath Oil Shale pilot wells, to maintain our acreage positions and to fulfill minor drilling commitments. Our 2012 capital expenditure budget is subject to change depending on a number of factors, including the availability and costs of drilling and completion equipment, crews, economic and industry conditions, prevailing and anticipated prices for oil and gas, the availability of sufficient capital resources, drilling success and other normal factors affecting the oil and gas industry.

We intend to fund our 2012 capital expenditures primarily through cash on hand and cash flow generated from operations, including cash flow from the assets to be acquired in the COP Acquisition. The majority of our cash on hand was generated through borrowings under our secured 15.0% senior term loan due 2013 of our principal U.K. subsidiary and the July 2011 offering of our 5.5% Convertible Senior Notes due 2016. The proceeds from the offering of our 5.5% Convertible Notes were originally expected to fund our acquisition of certain Marcellus shale play assets, but the transactions were not consummated and we are currently involved in litigation with the sellers.

Production Update for Quarter Ended December 31, 2011

Our average daily production for the fourth quarter of 2011 is expected to be between 4,000 and 4,500 BOE/d, of which oil and natural gas liquids will comprise approximately 25%.

Average daily production from the assets that we expect to acquire in the COP Acquisition is expected to be between 8,000 and 9,000 BOE/d for the fourth quarter of 2011, of which oil and natural gas liquids will compromise approximately 99%.

Terminated Acquisition of Marcellus Assets

On July 17, 2011, we entered into agreements (the “SM Purchase Agreements”) with SM Energy Company and certain other sellers named therein (collectively, “SM Energy”) for the purchase of oil and gas leases, producing properties, geophysical data, a pipeline and related assets in the Marcellus shale play in Pennsylvania (the “SM Acquisition”) for aggregate consideration of approximately $110 million (the “SM Purchase Price”). We terminated the agreements on December 14, 2011, based on our conclusion that (i) the title defects we identified, after analyzing SM Energy’s responses to the notice of defects and valuation of the defects, exceeded the contractual threshold of 15% of the purchase price for the applicable asset group ($85 million); and (ii) the condition of the pipeline was not in compliance with applicable regulatory standards, which would constitute a material violation of a representation and warranty contained in the applicable SM Purchase Agreement.

SM Energy filed a lawsuit against us in Texas state court on December 20, 2011 alleging that we breached the SM Purchase Agreements by terminating them and refusing to close on the transactions. Specifically, SM Energy has alleged, among other things, that most of our asserted title defects are without merit and, in any event, would not exceed 15% of the applicable purchase price. SM Energy seeks the award of unspecified actual damages, including costs and reasonable attorney’s fees, and specific performance. On January 17, 2012, we filed an answer and counterclaim denying the allegations and seeking the return of our $6 million deposit, which we believe we are entitled to recover pursuant to the terms of the SM Purchase Agreements, as well as for the damages that we suffered as a result of SM Energy’s misrepresentations. SM Energy has requested that the matters under dispute be submitted to arbitration. We intend to contest the case vigorously.

Summary Reserve Data

The following table presents summary data with respect to our historical estimated net proved oil and natural gas reserves and our estimated net proved plus probable (“2P”) oil and natural gas reserves, each as of December 31, 2011; the estimated net proved oil and natural gas reserves and the estimated net 2P oil and natural gas reserves to be acquired in the COP Acquisition, each as of December 31, 2011; and our estimated net proved oil and natural gas reserves and our estimated net 2P oil and natural gas reserves, each as of December 31, 2011 on a pro forma basis giving effect to the COP Acquisition.

The reserve estimates are based on evaluations prepared by our internal reserve engineers, and, for the properties to be acquired in the COP Acquisition other than Alba, derived from information provided by COP. The reserve estimates have been audited by Netherland, Sewell & Associates, Inc. The estimates of the present value of future net revenues before income taxes presented below are based on our internal estimates.

These reserve estimates were prepared in accordance with the SEC’s rules regarding oil and natural gas reserve reporting. The SEC defines “proved” reserves as those quantities of oil and gas, which by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible — from a given date

forward, from known reservoirs, under existing economic condition, operating methods and governmental regulations. The SEC defines “probable” reserves as those additional reserves that are less certain to be recovered than proved reserves but which, together with proved reserves, are as likely as not to be recovered. Probable reserves are by definition less certain to be recovered than proved reserves.

Pro Forma Summary Production and Operating Data

The following table presents pro forma production results and operating costs for the year ended December 31, 2010 and the nine months ended September 30, 2011. The unaudited pro forma information was prepared as if our COP Acquisition had occurred on January 1, 2010.

PV-10

Our calculations of PV-10 and standardized measure for our properties as of December 31, 2011, and PV-10 and standardized measure for the properties we expect to acquire in the COP Acquisition as of December 31, 2011, are based on estimates of proved reserves prepared by our internal reserve engineers, which have been audited by Netherland, Sewell & Associates, Inc. The following table provides a reconciliation of the standardized measure of discounted future net cash flows to PV-10 as of December 31, 2011.

Cautionary Note Regarding Forward-Looking Statements

The information set forth in this Exhibit 99.1 includes “forward-looking statements” intended to qualify for the safe harbors from liability established by the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933 (the “Securities Act”) and Section 21E of the Exchange Act. These forward-looking statements include statements that express a belief, expectation, or intention, as well as those that are not statements of historical fact, and may include projections and estimates concerning the timing and success of specific projects and our future production, revenues, income and capital spending. The Company’s forward-looking statements are generally accompanied by words such as “estimate,” “project,” “predict,” “believe,” “expect,” “anticipate,” “potential,” “plan,” “goal” or other words that convey the uncertainty of future events or outcomes. You should not to rely on them unduly.

The Company has based these forward-looking statements on our current expectations and assumptions about future events. While management considers these expectations and assumptions to be reasonable, they are inherently subject to significant business, economic, competitive, regulatory and other risks, contingencies and uncertainties, most of which are difficult to predict and many of which are beyond the Company’s control. These risks, contingencies and uncertainties, which may not be exhaustive, relate to, among other matters, the following:

Any of these factors, or any combination of these factors, could materially affect our future financial condition or results of operations and the ultimate accuracy of a forward-looking statement. The forward-looking statements are not guarantees of the Company’s future performance, and the Company’s actual results and future developments may differ materially from those projected in the forward-looking statements. In addition, any or all of the Company’s forward-looking statements included in this Exhibit 99.1 may turn out to be incorrect. They can be affected by inaccurate assumptions we might make or by known or unknown risks and uncertainties, including those mentioned in “Risk Factors” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2010. These forward-looking statements speak only as of the date hereof. Except as required by law, the Company undertakes no obligation to update publicly or release any revisions to these forward-looking statements to reflect events or circumstances after the date hereof. These cautionary statements qualify all forward-looking statements attributable to the Company or persons acting on its behalf.