It is the key study how to make sure the pressure distribution of liquid in the pump barrel and to study the pump valve-ball's movement to improve the systematic efficiency.

对有杆抽油泵泵阀运动规律的研究和确定抽油泵泵阀筒内液体压力的分布是提高抽油机井系统效率研究的关键性课题。

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The bending of pump barrel will not happen as low part fixed pumping piston going downward that only happens when it works in heavy oil well.

而泵筒下部固定泵柱塞上行时，泵筒不会发生弯曲，只是其柱塞在稠油井中下行时泵筒才会发生纵向弯曲。

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Sweet light crude oil yields the most gallons of gasoline per barrel of oil and since it has low viscosity and low density, it is comparatively inexpensive to pump, transport, and refine.

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Light, sweet crudes are cheaper to pump, transport, and distill and produce more gasoline per barrel than other types of crudes so it generally goes for more dollars per barrel than others.

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