Vancouver, BC V6J 1X2

Tel 800 828 1866

TSX Symbol: PSH

Bulletin Board: PRRPF August 31st, 2004

Mission River August 31st. 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 this twelve well project . Five wells have been completed and all five have been placed on production.

Scanio/Shelton Well No. 1

This well is the fifth well drilled and completed on the project. The productive

zone was perforated on August 28th. The well made oil after recovering load

water. Production is through a 12/64” choke and the well is flowing under its own pressure. The well made 78 barrels of oil and no water over a twenty four hour period. The flowing tubing pressure was between 100 and 200 psi.

The operator has hooked up the well into production equipment on the property

and will continue to test the well. The well which has several prospective oil and gas horizons reached total depth on Thursday August 19, 2004.

Scanio/Shelton Well No. 2 , No. 3, No.4, No.5, (on production, gas and condensate)

All four wells have been placed on production, producing gas, oil and

condensate. An evaluation of the first five wells is underway at present. Results of this evaluation will be available in the coming weeks.

Information on the company can also 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.