When oilfield development is in medium-later period, gas will occur in fluid flow due to the draw down of reservoir pressure.

当油田开发到中后期，由于地层压力的下降，实际上往往有气相参与流动。

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Graduate, create, say to be one summary of study and life for less than four year, four year in everybody youthful time draw down the intact period.

毕业创作可以说是四年学习生活的一个总结，为每个人的四年青春岁月划下完整的句点。

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