抽油泵柱塞和泵筒环隙漏失研究进展及方向

准确预测抽油泵柱塞与泵筒环隙漏失量,对抽油泵间隙的选择至关重要。间隙选择过大,会使抽油泵漏失量增加,严重影响其泵效和油井产量; 间隙过小,虽然漏失减小,但加剧了柱塞与泵筒的摩擦,影响柱塞和抽油泵的使用寿命。基于国内外对抽油泵柱塞和泵筒环隙漏失方程的研究,分析了理论推导法、试验推导法、数值模拟法3种漏失模型的推导方法,阐述了抽油泵柱塞和泵筒环隙漏失量的研究进展。研究结果表明:当间隙<0.127 mm时,柱塞偏心对漏失量影响较小; 当间隙>0.127 mm时,偏心对漏失量影响较大; 剪切漏失量在总的漏失量中所占比重较大,剪切漏失与压差漏失异向时,会出现负漏失。指出了抽油泵柱塞-泵筒环隙漏失方程的发展方向:从试验角度确定剪切漏失和压差漏失的方向; 同时要对特殊抽油泵的间隙漏失模型开展研究。为更好地指导油井的生产,应结合泵效的其他相关影响因素,借助大数据处理分析,获得最佳的泵效。

Research Progress and Direction of Plunger-barrel Annular Leakage for Rod Pump

It is very important to predict accurately the amount of leakage between plunger and pump barrel.Too large clearance selection will aggravate the oil pump leakage and seriously affect the pump efficiency and oil well production.When the clearance is too small,although the leakage decreases,it will increase the friction between plunger and barrel,and affect the service life of plunger and pump.For this reason,based on the investigation and summary of the leakage equation of plunger and annular gap of pump barrel at home and abroad,three kinds of leakage model derivation methods,including theoretical derivation method,experimental derivation method and numerical simulation method,were comprehensively analyzed and the research progress of the leakage amount of plunger and annular gap of pump barrel was expounded.The results show that:(1)When the gap is<0.127 mm,eccentricity of the plunger has a smaller impact on the leakage.When clearance>0.127 mm,eccentricity has a major impact on the leakage.(2)Shear leakage accounts for a large proportion of the total leakage,and negative leakage occurs when shear leakage and pressure difference leakage are in different directions.On the basis of the above research,the development direction of plunger-pump barrel annular gap leakage equation was pointed out.At the same time,the clearance loss model of special oil pump should be studied.Finally,so as to better guide the production of oil wells,the best pump efficiency should be obtained by big data processing and analysis combined with other relevant factors of pump efficiency.