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
initial formation pressure at zero time | |
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 | |
| |
A speed of -th well total sandface flow rate variation |
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing / Pressure Testing
[ Well & Reservoir Surveillance ] [ Pressure Diffusion ] [ Pressure drawdown ]