Dear Newbie,

Thanks, for the reply. I was able to generate the Log WOR vs Np in OFM but like you said I takes some trick OFM Syntax. In the end I gave up and used Excel, but I used Watercut vs Np and it worked.

What I did here was generate a forward Np forecast extrapolating the watercut trend (just used slope and intecept funtions) to determine the linear Watercut extrapolation.

I then fixed the total fluids liquid rate and then selected an oil exponential decline rate and summed up the production month by month (Np) and since I new the Np vs Watercut relationship I could calculate the watercut profile at each monthly production. I then overlayed that watercut profile from the monthly production against the Np vs Watercut extrapolation and simply adjusted the oil decline rate until I had an overlay.

The key here is to fix the total liquids rate, then if you have linear extrapolation on the Watercut vs Np curve then the oil decline must be exponential.

It would great if you could post an OFM tutorial and I'll see if your method works in OFM 2009 and let you know.

Thanks

Rgrds
Chee Koh Peh