News Release                                                       July 17, 2006


Evolution Petroleum Corporation Announces Listing on the American Stock Exchange

(Houston, Texas) EVOLUTION PETROLEUM CORPORATION, formerly Natural Gas Systems,
Inc. (OTC:NGSY), is pleased to announce today that its common stock will begin
trading this morning on the American Stock Exchange ("AMEX") under the EPM
ticker symbol. The Company selected J. Streicher & Co. Ltd as its trading
specialist.

Robert Herlin, President and Chief Executive Officer of Evolution Petroleum,
said, "We are very pleased with the listing of our shares on the American Stock
Exchange, and consider this move to be one more major milestone accomplished in
our growth. We believe that being on the AMEX will help us to attract a broader
shareholder base and provide our shareholders with a more liquid and efficient
market in which to trade."

Evolution Petroleum Corporation (www.evolutionpetroleum.com) (AMEX:EPM) acquires
and develops mature oil and gas resources and applies conventional, specialized
or proprietary technology to accelerate production and develop incremental
reserves and shareholder value. The Company currently owns interests in a
planned enhanced oil recovery project in the 13,636 acre Delhi Field in
northeastern Louisiana and a 100% working interest in smaller fields in north
central Louisiana.

Safe Harbor Statement

All statements contained in this press release regarding potential results and
future plans and objectives of the Company are forward-looking statements that
involve various risks and uncertainties. There can be no assurance that such
statements will prove to be accurate and actual results and future events could
differ materially from those anticipated in such statements. The Company
undertakes no obligation to update or review any forward-looking statement,
whether as a result of new information, future events, or otherwise. Important
factors that could cause actual results to differ materially from our
expectations include, but are not limited to, those factors that are disclosed
under the heading "Risk Factors" and elsewhere in our documents filed from time
to time with the United States Securities and Exchange Commission and other
regulatory authorities. Statements regarding our ability to maintain the listing
of our shares on the AMEX, our ability to attract a broader shareholder base and
the enhanced liquidity in our shares as a result of such listing, our ability to
successfully identify and acquire new properties, and our ability to complete
transactions, successfully apply technology applications in the re-development
of oil and gas fields, realize future production volumes, realize success in our
drilling and development activity, prices, future revenues and income and cash
flows and other statements that are not historical facts contain predictions,
estimates and other forward-looking statements. Although the Company believes
that its expectations are based on reasonable assumptions, it can give no
assurance that its goals will be achieved and these statements will prove to be
accurate. Important factors could cause actual results to differ materially from
those included in the forward-looking statements.


For additional information contact:

Investor Contact:            John Liviakis, Liviakis Financial Communications,
                             Inc.
                             (415) 389-4670

Evolution Petroleum Contact: Sterling McDonald, Chief Financial Officer
                             (713) 935-0122