The relationships between productivity index and producing pressure drop of the producing wells of different producing formation patterns are established through studying the change of oil producing capacity of the producing wel.

According to onsite data and the correlation of sand production rate to oil properties, perforation extent, producing pressure drop and reservoir properties, the favorable values of the parameters controlling sand flow are derived, that is, oil density lower than 0.

The coning of bottom water will happen as soon as the producing pressure drop of a well is higher than the difference of gravity caused by the difference of density between oil and water.

Selection of reasonable drawdown pressure with consideration of deformation effect for low permeability gas reservoir;

udy on reasonable drawdown pressure of oil reservoir with low-permeability deformed media.;

Determining method for resonable drawdown pressure of oil reservoir with edge and bottom water;

An approach to the variations in trigger producing pressure differences under different water-table regimes;

How to determine reasonable producing pressure difference in pumping wells during different development phases

According to this,the formula for calculating producing pressure differences of the interwell fluid units could be established.

The studies of the variation of the fluid productivity index for different microfa-cies with increasing production differential pressure show that fluid productivity index of channel sand decreases faster than that of edge sand with the increas.