关键词: 多油砂体, 组合油层, 注水开发, 压力恢复曲线, 计算公式

Abstract: In the water injection stage,some new spectacles can be observed,because the water-flooding effects are very different in relative sandy bodies.The solving approach based on superposition principles may lose some needed information,so that a new method is presented.The water-invaded sandy bodies have to split up in the middle positions among injectors and producers,and the bounded conditions to be set up.The multiphase flows in gas-oil and water-oil sand bodies were changed into enlarged single-phase flows.The observed information and enlarged results are all put into the boundary and initial conditions.A set of analytical formulas may be obtained by solving a partial differential equation,and many kinds of pressure build-up curves can be plotted on the basis of diverse parameter combinations.This work not only could be used to enriching our knowledges for interpretations but also indicates the application of "third segments",which is very favorable for discovering remainingoil in the ineffective oily sandy bodies by using water-flooding.

Key words: multiple oily sandy bodies, composed reservoirs, water injection, pressure build-up curves, formulas