任丘油田雾迷山油藏抽油机井系统效率初步探讨

总公司1996年对任丘雾迷山油藏抽油机井进行测试,系统效率高达51%~68%,其结果出乎意料。从影响抽油机系统效率的几大因素入手,分析出任丘雾迷山油藏抽油机井系统效率高的主要原因。任丘雾迷山油藏属裂缝性破酸盐岩油藏(即灰岩油战),由于其裂缝发育、渗透性好、油层厚度大、地层温度高、油气比小、饱和压力低等,使得抽油机井生产呈现如下特点:()大泵径,长冲程,低冲次大排量采油;(2)中浅京挂,小沉没度;(3)抽汲流体为液体单相,泵充满程度高;(4)部分井为连抽"带喷"状态,抽油系活塞底部受力大;(5)井液粘度低,油井不结蜡,摩阻损失小。由于这些特点以及近年来使用的新型节能抽油机,使得抽油机井系统效率大大高于其它油田抽油机井系统效率。

PRELIMINARY INVESTIGATION TO EFFICIENCY OF PUMPING SYSTEM IN WUMISHAN RESERVOIRS OF RENQIU OIL FIELD

Measurement to pumping system in Wumishan reservoirs of Reqiu oil field conducted by CNPC experts showed that the efficiency of this system reaches to 51 % ~68%,the resu1t was unexpected. This paper, by analyzing the main factors influencing the well pumping unit system, finds out the main reasons why the efficiency of the pumping system in Wumishan reservolrs of Renqiu oil field is high. This paper points out: Wumishan reservoirs in Renqiu oil fleld are fractured carbonate reservoirs (limestone reservoirs), in which, frac-ture developed, permeabil1ty is good, oil reservoir is thick, formation temperature is high,gas/oil ratio is low, saturation pressure is low and so on, all these cause the oil producing with well pumping unit possess the following characteristics: (1) produce oil with large pump size, long stroke, low pump speed and high pumping rate ; (2) pump setting depth is rniddle to shallow. submergence is small: (3) swabbing fluids are single phase liquid, full degree of pump is high; (4) some wells are in the state of " pumping accompanied by flowing" forces exerted on the bottorn of pump piston are large (5) viscosity of fluids in well is iow. paraffin does not deposit in well, friction loss is small. All these characteristics and the rlet` type energy savlng weli pumping units used in recent years make the efficiency of pumping systern in thls oll f1eld more hlgher than that in the other oil fields.