Inverse problem to pressure convolution, performed as a fully or semi-automated search for initial pressure for every well and Unit-rate Transient Responses (UTR) for wells and cross-well intervals in order to fit the sandface pressure response (usually recalculated from PDG data using wellbore flow model for depth adjustment ) to total sandface flow rate variation history (usually recalculated from daily allocations based on surface well tests).
The basic element of deconvolution is the pressure Unit-rate Transient Response (UTR) which is a sandface pressure response to the total sandface unit-rate production. Multiwell deconvolution (MDCV) specifies two types of UTR: Drawdown Transient Response (DTR) and Cross-well Transient Response (CTR). The Drawdown Transient Response (DTR) is the sandface pressure response of a given well to its total sandface unit-rate production in absence of the other wells. It is equivalent to conventional Drawdown Test with sandface unit-rate production.
The Cross-well Transient Response (CTR) is the sandface pressure response of a given well to the total sandface unit-rate production of the offset well in absence of the other wells.
It is equivalent to the Pressure Interference Test with the unit-rate production in disturbing well.
The pressure convolution principle itself has some limitations and may not be adequate for some practical cases. For example, changing reservoir conditions, high compressibility – everything which breaks linearity of diffusion equations. There are some workarounds on these cases but the best practice is to check the validity of pressure convolution (and therefore the applicability of MDCV) on the simple synthetic 2-well Dynamic Flow Model (DFM) with the typical for the given case reservoir-fluid-production conditions.
MDCV can be performed in two options: Radial Deconvolution (| Hint |
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