Vancouver, BC V6J 1X2

Tel 800 828 1866

TSX Symbol: PSH

Bulletin Board: PRRPF August 6, 2004

Mission River August 6th. update

Portrush Petroleum Corporation is pleased to announce an update from the Mission River Oilfield in the Gulf Coast region of Texas, near Corpus Christi, in Refugio County, Texas. Portrush has a 10% working interest in the project. Three wells have been completed and have been connected to the gas sales line. A fourth well has reached total depth, is awaiting completion and a fifth well will commence drilling early next week. The next location will be chosen to build on the success achieved thus far and also help in the overall evaluation of the project. The “Vicksburg age “Massive Sand” formation in this area has produced almost a billion barrels of oil and several TCF of gas since the field was first discovered in the nineteen thirties.

Scanio/Shelton Well No. 3

The well which has several prospective oil and gas horizons was perforated on Thursday August 5th. and was tied into the gas sales line the same day.

The well is flowing 330 MCFD with 1,000# psi FTP on a 8/64” choke.

Note

Bottom hole pressure of this zone is only 1308 psi. This well should

produce in excess of 500 MCFD after the compressor is installed next week.

Scanio/Shelton Well No. 2 & Scanio/Shelton Well No. 4

(on production, gas and condensate)

Both of these wells have been connected to the sales pipeline. The No.2 well has been on production for over a month, the No.4 since July 20th.

Scanio/Shelton Well No. 5

This well reached total depth at 6,515’. Downhole wellbore surveys (“logs and sidewall cores) have been run. Multiple very good shows of oil and gas throughout interval 5,700’ - 6,515’. A decision to complete the well has been taken and 4-1/2” casing has been set. The service rig has been moved on to this location. Because of excessive heat the crew has been allowed the weekend off and the well will be perforated early next week.

Information on the company can be obtained by calling (800) 828 1866 or at

www.portrushpetroleum.com

The company relies on litigation protection for “forward looking statements”.

ON BEHALF OF THE BOARD

/s/

M.Cotter

President

The TSX Venture Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.