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;

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.

. 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.

On the basis of the true data of Ansai Oilfield in Chang qing and Liangjing Oilfield in Jilin, using XIE formula,former Soviet empirical formula and domestic empirical formula, a discussion on the relation between waterflooding recovery and well spacing of fracturing well pattern of low permeable reservoir is made.

Based on the understand of residual oil distribution, the calculation result of reasonable, practical and economical well spacing, the analysis of reasonable well array distance and the effective prediction of well array with small distance, it is believed that the spacing between the injecting and producing wells is too large.

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.

This paper derivates a method for calculating reasonable well spacing density of low permeable reservoirs through economic evaluation considering drilling investment, surface investment and oil sale income, and the interest of the three.