(n). Well Testing. A virtual well used to mathematically create the effect of a flow barrier. The pressure transient behavior both at the well and in the reservoir is identical for the following two cases: (1) a well near a barrier represented by a plane normal to the bedding, or (2) a well producing or injecting at the same rate as the tested well. In the second case, the effect is of a barrier bisecting the space between the two wells. See: bed, injection well, producing well