 The pressure began to decline rapidly towards the turn of century.In 1895 the pressure was at 164 psi, in 1897 it was 191 psi, in 1898 173 psi.As the pressure decreased to around 150 psi, oil began to move into the upper part of the field, but since the natural gas had been released and pressure dropped between 130 psi, there was no way to pump out the remaining oil in the field.