Press Release                                          Natural Gas Systems, Inc.


Natural Gas Systems Announces Name Change to Evolution Petroleum Corporation
Thursday July 13, 7:30 am ET

HOUSTON, July 13 /PRNewswire-FirstCall/ -- NATURAL GAS SYSTEMS, INC. (OTC
Bulletin Board: NGSY - News) today announced that it has changed its name to
Evolution Petroleum Corporation to better reflect the business model
successfully applied since the founding of its predecessor company in 2003.
Evolution Petroleum acquires mature oil and gas fields in order to apply
technology and capital to substantially restore production and profitability.
The technologies employed and being developed include carbon dioxide enhanced
oil recovery and a proprietary artificial lift process.

As previously reported in June 2006, Evolution Petroleum received approximately
$50 million in cash and a 25% reversionary working interest in connection with
the sale of its 100% working interest (80% net revenue interest) in the
Company's Delhi Field Holt Bryant Unit and a 75% working interest (60% revenue
interest) in certain remaining depths in the Delhi Field outside of the Holt
Bryant Unit. The purchaser, the leading operator of carbon dioxide enhanced oil
recovery projects along the Gulf Coast, has financially committed to install a
carbon dioxide enhanced oil recovery project in the Holt Bryant Unit in
accordance with specified minimum annual capital expenditures. The reservoirs
targeted for CO2 injection have cumulatively produced approximately 190 million
barrels of oil from conventional primary and pressure maintenance techniques, an
amount believed to be approximately half of the estimated original oil in place.
Following the sale, Evolution Petroleum retained a 4.8% royalty interest in the
Unit, a reversionary working interest in the Unit and a 25% working interest
(20% net revenue interest) outside of the Unit in certain depths of the Delhi
Field.

Evolution Petroleum Corporation (http://www.evolutionpetroleum.com), formerly
Natural Gas Systems, Inc., acquires and develops mature oil and gas resources in
order to apply conventional and specialized technology to accelerate production
and develop incremental reserves. The Company currently owns interests in a
planned enhanced oil recovery project in the 13,636 acre Delhi Field in
northeast Louisiana and a 100% working interest in other 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 successfully
identify and acquire new properties, complete transactions, successfully apply
technology applications in the re-development of oil and gas fields, realize
future production volumes, realize success in our drilling, development and
recovery activities, 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