Greetings all,

Just wonder if anyone here could share experience in workflow calculating original oil in place for tight reservoir. I am dealing with lacustrine depositional environment so the reservoir is interfingering sand-shale. I have done assessing the fluid contact for the reservoir but as you can imagine its difficult to define single fluid contact, for example I have lowest known oil (LKO) in well #2 but in another well I found water column above that level (they are at the same reservoir defined by stratigrapher), I guess it is common to have localized sand in lacustrine type of reservoir.

I have been told to breakdown the well marker into more fine detail sub-reservoir (FYI, the current marker from top to base is 300ft thickness in average), then calculate the reserve for each individual one. This is a bit tough for me knowing the depositional environment is lacustrine and also very limited 2D line seismic to guide the interpretation and some drilled wells penetrate the reservoir partially only.

Appreciate if anyone could shed some lights on this matter.