Experimental Analysis and Application of All-Metal Conical Progressive Cavity Pump

Chen Xiaochun （Sinopec Xinjiang Xinchun Petroleum Development Co.，Ltd.）

Abstract： The stator and rotorof all-metal progressive cavity pump adopt a clearance fit，and fluids of diferent viscosities require different clearances to achieve optimal production status.In this paper，anew type of allmetal conical progressive cavity pumpoil production system was developed.The stator and rotorof the progressive cavity pump adopts aconical structure，achieving a two-way adjustment of the stator and rotor clearance through a surface rotationalifting assembly.Theabove-ground protection assembly can compensate the tubing length variationand preventthe tubing from tripping.The balancing assemblycan keep the stator and rotor clearance stable in the production process.Then，a 2O m test well was constructed to analyze the influence of rotor position on the operating characteristicsof the pump，showing that whenthe rotor position is reduced to6mm，the volumetric efficiencies corresponding to 5 MPa and 1O MPa working pressure differences are 98.2% and 75.4% respectively， while the pump efficiency reaches its highest level，which is 49. 6% and 38.9 % respectively. As the rotor position further decreases，the volumetric eficiency increases slowly，the friction between the stator and rotor intensifies， and the mechanical eficiency sharply decreases.When therotor position is greater than 1O mm，as the rotor position increases，the mechanical efficiency corresponding to a working pressure difference of 5 MPa is about 50% 1 （204号 55% ，and there is a downward trend. Considering all factors，the rotor position should be greater than 10mm （204号 during operation.Finally，the all-metalconical progressivecavity pump was applied in thermal recoveryheavyoil wellof Xinchun oilfield.The field application results show that compared tooil production with pumping unit in offset well， the all-metal conical progressive cavity pump increases production time by 52. 1% and liquid production by 15.2% ，reduces daily average power consumption by 64.3% and power consumption per ton of liquid by 52.7%.Compared tooil production with pumping unit in the same well，the daily average liquid production is increased by 39. 4% ， the daily average power consumption is decreased by 66. 6% ， and the power consumption per ton of liquid is decreased by 76. 1% . The research results show that the oil production system meets the requirementsof efficient lifting of oilfields，and especiallyhas goodadaptabilityto thermal recoveryheavy oil wells.

Keywords： all-metal conical progressive cavity pump ； stator and rotator clearance； viscosity; thermal recovery of heavy oil；volumetric efficiency；mechanical efficiency

0 引言

螺杆泵在稠油、高含砂以及高气油比油井采油有明显的优势。随着特、超稠油油藏的开发动用，注蒸汽热采工艺已经得到广泛应用，在生产时井筒温度能达到 350^∘C 以上。常规螺杆泵定子橡胶在高温、高压、原油和外界力的作用下会产生老化，缩短螺杆泵寿命。其中原油温度对定子橡胶的老化影响最大[1-2]

法国PCM和TOTAL公司于1990年中期开始研制全金属螺杆泵，于2007年注册并生产PCMVul-cainTM系列全金属螺杆泵。国内于1998年由大庆油田宋志超[申请了“金属定子螺杆泵”专利。2000年辽河油田车天之[4申请了“全金属螺杆泵”专利。全金属螺杆泵可以适应稠油热采井的高温环境。加拿大Joslyn油田2006年首次采用蒸汽辅助重力泄油金属螺杆泵采油[。全金属螺杆泵定转子采用间隙配合，不同的流体黏度适合不同的定转子间隙，但是间隙调节困难，而且容易卡泵，所以一直未大规模应用。

近些年，对全金属螺杆泵的研究主要集中在泵的工作特性方面。熊建新等研究了全金属螺杆泵的压差、转速，油液黏度对泵容积效率和总效率的影响。陈舟圣等通过试验分析不同转速、不同压头、不同黏度度条件下全金属螺杆泵特性。李增亮等[8-9]通过有限元模拟全金属螺杆泵在不同黏度下的泵效随配合间隙的变化规律，给出了各种黏度下的间隙优选图，稠油热采（低黏度）时，配合间隙在 0. 10～0.30mm 之间选取，稠油冷采（高黏度）时在 0.30～0.50mm 之间选取；并在模拟的基础上，试制全金属螺杆泵样机，对泵特性进行试验分析。……