The original reservoir pressure is obtained by extrapolating the middle-time semilog straight line to （）.

The original reservoir pressure is obtained by extrapolating the middle-time semilog straight line to （）.
A.（tp-Δt）/Δt=1
B.（tp+Δt）/tp=1
C.（tp-Δt）/tp=1
D.（tp+Δt）/Δt=1
正确答案：（tp+Δt）/Δt=1