Reserves Estimattion without production history

[sanjeevk4u]

Hi friends,
This is my first post on this forum.
I'm working on a gas condensate reservoir having very limited/no production- pressure history. What could be the best methods for reserves estimation under these conditions when no produciton history is available. Would appreciate to know from the people having more experience on gas-condensate reservoirs.

Thanks & regards,
Sanjeev

[vinomarky]

Simple reservoir simulation model

[temr]

Will agree with vinomarky
bit also try to look for analog fields.
For reservoir estimation you do not need mach production data.
but for recovery factor , you need it
normally Rf of gas filed is in the range of 60-80 percent of wet gas
but RF is a economical factor

[Yengineer]

What is limited? You must have drilled a well or two. You must have some liquid/gas samples (preferably downhole). You should also have an idea about the reservoir exteension and thickness from geology or seismics.
What about volumetrics then?
Saturation values can be estimated from logs, or core data if any. Pressures - you can choose to go with normaly pressured reservoirs (0.44psi/ft). You can also consult drilling reports for the fluid density used during drilling - any signs of kick which might indicate overpressure. The RF has to be guestimated.

[i-anuar]

Just to add to the posts above you would have range of volumes from oil down to (min) and spill point (high) with potential gascap unless PVT proves different and area from the maps/seismic. Regarding terminology you would have RESERVES if you confirmed hydrocarbons by drilling (commercial flow better) and have approved development plan which expected to materialise within ~5 years. in rare cases if big company expresses publicly intention to develop field some volumes could be written to reserves. in most other cases it would be resources...

[sanjeevk4u]

Many thanks friends for the valuable informations.
I would like to correct the word I used in my query "RESERVE", assume there is no economic constraints/limit, how would you determine the reserves to be drained (RTBD) from a well in this gas condensate reservoir. This well has very limited production history from this reservoir tested/flowed for two months only in 2009 and since then producing from other reservoir.
I already did volumetric estimates of GIIP but recovery factor has more uncertainties.
Anyways the methods you guys mentioned really helped me enhancing my confidence on methods I applied.

Thanks again,
Sanjeev

[shawn6820]

Essentially four methods are used for reserves estimation: volumetric, material balance, decline curve analysis and reservoir simulation.

If there is no production history or there is no production wells, the best method to estimate reserves is volumetric method. This method has high uncertainty. You can get required data from analogous field.

Hi friends,
This is my first post on this forum.
I'm working on a gas condensate reservoir having very limited/no production- pressure history. What could be the best methods for reserves estimation under these conditions when no produciton history is available. Would appreciate to know from the people having more experience on gas-condensate reservoirs.

Thanks & regards,
Sanjeev