Volumetric calculations for shale gas

I am interested to know if the currnet volumetric calculator tools available are capable of accurately computing reserves and recoverable reserves in shale gas reservoirs.

What is proven to be the best volumetrics tool for calcualting recoverable reserves in shale gas?

Thank you

Paul

Paul,

Interesting question! I know our workflows ae just being formalised as this is a relatively new problem. I believe the main problem lies in the fact that most static modeling (and dynamic) packages relly on GRV (contacts & structure) and some rock properties (N/G, POR, Sat, recovery factor related mostly to permeability) to estimate the recoverable reserves for hydrocarbons. For unconventionals contacts are no longer important, GRV can be irrelevant (very extensive 'reservoirs'), porosity is off the scale and permeability relies on what one does to the wells (fracking). Packages will need to be able to model large extensive fields while maintaining resolution around the well. Apart from that temperature starts playing an important role. I have also not seen a good 3D modeling suite that can incorporate all this and also allows one to model fractures accurately.

In the end I believe volumes and reserves for unconventionals cannot be estimated using static models, but require complex dynamic models. Often flow is fast at first, but may decline very fast as one basically is working with two permeabilities: one for the fractures and one for the shales itself.

To answer your question... I can not suggest a tool (I know off) that handles shale gas reservoirs in such a way that is currently used/proven for conventionals.

Thanks O.

Do you think there is a reason that a tool has not been developed? for example do the traditional software vendors which develop these tools not see a commercial market, or are geologists and reservoir engineers happy making do with existing tools and applying approximate constraints to estimated recovery volumes, drainage area and so on?

Regards

Paul

Well, I think the main reason is that a standard guideline/best practice has not been formulated yet. There are guidelines for reserve booking (this tool uses them: http://www.exprodat.com/Software/TGUA/) but for more 'geologically' sensible estimations still a lot of work needs to be done. The current tools do allow one to experiment and are quite flexibel in how to calculate volumes and simulate flow, so for the time being the are sufficient I think.

O.

Without wanting to pressure you to state your preference....
what would be your current tool of choice?

Regards

Paul

Paul,

Sorry for the delay in my response and possibly for creating some comfusion. When I stated "The current tools do allow one to experiment..." I was talking about current conventional static modeling tools. In that sense I prefer Petrel as it gives the user a lot of flexibility in calculating volumes and modeling properties/fractures. There are also some plug-ins more focused on unconventioanls, but I have no seen them used here.

Hope that helps.