Inter-layer connectivity from well test
A possible tip to establish inter-layer reservoir connectivity. It utilises the kh obtained from the derivative plot of the BU:
The horizontal portion of the derivative plot represents infinite-acting-radial-flow and gives kh of the volume of reservoir detected by the pressure transient.
>Now, suppose after this build-up (BU), an additional wellbore interval is open to flow and the BU recorded. If the BU analysis gives the same kh, it is evidence that the pressure transient of this second BU detects the same reservoir volume as before. This would indicate the layers are connected.
We have found this approach useful in appraisal well testing of low quality gas-bearing formations. The results allow deciding if subsequent producer wells need to penetrate all of the reservoir column to recover all reserves.