Lean gas injection in a fractured reservoir: Compared performance of nitrogen and methane injection

A laboratory technique has been developed to perform. natural gas/oil gravity drainage experiments under reservoir conditions, in one or three dimensions, that is on cores having or not the lateral faces open to flow. As an application to the EKOFISK reservoir, a series of experiments has been performed on outerop cores (limestone, chalk) of various permeabilities and capillary hold-up heights, in order to compare the efficiency of methane or nitrogen injection.