Simple Approach to Design Capillary Pressure Curves for Dynamic Models

ADNOC "Fast-Track" approach has been designed to assist simulation reservoir engineers to initialization their dynamic model in very short time period, which contributes in achieving:

• Minimum volumetric gaps between static and dynamic models in term of fluids-in-place. i.e. (encouraged fluids saturation matched laterally and vertically between static and dynamic models with gaps below 1.0 %).
• Better match with initial water saturation logs data. (included horizontal wells profiles).
• Better description of hydrocarbon column thickness and top of transition zone i.e. (more flexibility to adjust shape of the Drainage Pc's curves to boost or cut-down water/gas movability to obtain better history match).
• Reduce computer timing and CPU’s while contribute in dynamic model stability.
• More realistic physics i.e. (better representation of the height of the liquid rises in a capillary tubes).

Its known that simulation tools are using Drainage Pc's curves just to distribute oil/water saturation's in 3D dynamic model, while fluids displacement calculation are performed by Inhibitions Pc's curves after initialization.

The following plots are showing (A) the log water saturation profile for a model, which reported with low water cut production historically and no water production measured during the production tests from deep perforations nearby FWL's depth intervals. (B) is showing the proposed Sw_pc curves that were used to initialize dynamic model, which it would slow-down water movement in the dynamic model while honoring capillarity tubes concept.

Having as such drainage Pc's curves shall thinner the definition of the transition zone and slow-down water movement without needs to tuning Kr's curves shapes and/or using unsupported Swct's values.

Of curse those Pc's curves should not be used to replace SCAL measured data, however it can be implemented in case of luck of SCAL data, or inaccurate measurement or just to speed-up modeling work until construct better relationships between permeability-porosity and RRT's to achieve better trends of Sw_log vs Height above FWL's depths.