A concept of economic recovery is presented,and on the basis of a relationship between oilfield investment and economic limit density of well pattern and an available equation,a practical model of economic recovery is established from the economics law of input output balance.

A new method of calculating rational well spacing density in late stage of high water cut;

Analysis on Reasonable Economic Well Spacing Density of Wangchang Oilfield;

Preliminary study of well spacing density for Yuedong heavy oil reservoir;

. Coinputation of economical well density using a trial method;

Based on net present value principle with geological and economic parameters affecting limit well density, a calculation method of economy limit well density was introduced in the paper.

Determination of economic limit for well pattern density of oilfield;

By means of the analysis for the fluid and development characteristics of low permeability oil reservoirs,we have found out the major problems existing as the low well pattern density,less precise development sequence classification,less injection-to-production-well ratio.

Reasonable well pattern density is pivotal decision-making parameter at oilfield development first stage.

Having entered into the later period of high water cut in Gaotaizi reservoir, pressure difference between blocks is bigger, oil-to-water-well ratio is higher and pattern density is lower.