For the pressure diffusion with constant diffusion coefficients and homogeneous boundary conditions the pressure response  in one well to a complex flowrate history  in the same well honours the convolution equation:

p(t) = p_0 + \int_0^t p_u(t-\tau) \, dq(\tau) = p_0 + \int_0^t p_u(t-\tau) \, \dot q(\tau) \, d\tau 

where

Drawdown Transient Response


a pace of sandface flow rate variation per unit time



In case a well is interfering with the offset wells the pressure in a given well   may respond to the offset wells  and the multi-well form of convolution is going to be:

p_n(t) = p_{n, 0} + \sum_{m=1}^N \int_0^t p_{u,nm}(t-\tau) \, dq_m(\tau) = p_{n, 0} + \sum_{m=1}^N \int_0^t p_{u,nm}(t-\tau) \, \dot q_m(\tau) \, d\tau = p_{n, 0} + \int_0^t p_{u,nn}(t-\tau) \, \dot q_n(\tau) \, d\tau + p_{n, 0} + \sum_{m \neq n}^N \int_0^t p_{u,nm}(t-\tau) \, \dot q_m(\tau) \, d\tau

where

Initial formation pressure at zero time for the -th well

Drawdown Transient Response in the -th well to the unit-rate production




Cross-well Transient Response
in the -th well to the unit-rate production in -th well



A speed of -th well total sandface flow rate variation


See also


See Also


Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing / Pressure Testing

Well & Reservoir Surveillance ] [ Pressure Diffusion ] [ Pressure drawdown ]

Convolution @math ]