Application of ESPCP System in the oil exploitation industry

1.  Introduction to industry

    The Electric Submersible Progressing Cavity Pumping (ESPCP) System is mainly used in the oil exploration industry. It can partially replace the domestic mechanical oil production mode, including China National Petroleum Corporation (CNPC), Sinopec Group and China National Offshore Oil Corporation (CNOOC).There are more than 20,000 oil wells in domestic oil exploration industry and more than 50,000 oil wells abroad. So the market space is very broad. 


2.  Customer introduction

    At present, the domestic customers include Daqing Oilfield, Dagang Oilfield, Jidong Oilfield, Liaohe Oilfield and Changqing Oilfield under CNPC, Shengli Oilfield and northwest petroleum bureau under Sinopec Group, and have carried out preliminary experiments in CNOOC. Foreign markets include Africa, central Asia, Russia and North America.

3.  Performance Introduction

    Aiming at deep well production, the system optimizes the control algorithm of frequency converter and adopts the vector control technology of long-distance and encoder-free to realize the accurate control of the speed and current of submersible motor. The submersible motor adopts the low-speed permanent magnet synchronous motor, which has the characteristics of large starting torque and high efficiency. The pump can be driven directly by motor without reducer, and its structure is simple, safe and reliable. In addition, the intelligent operation is realized by using Downhole sensor and APP remote control, which opens up a forward-looking innovative practice for digital production. The system can be widely used in horizontal wells, low production wells, heavy oil wells, sand wells and inclined wells, reduce energy consumption of single well and save production costs.

4.  Product solutions and Technical principle diagram

    At present, most of the oil wells in China have entered the mid-and late, the mining become more and more difficult. Various new technology and new materials are emerging, but they have not solved the common problem of high energy consumption. Our company uses servo control technology and adopts the solution of direct drive of submersible motor plus intelligent ground control, so that the energy saving rate is higher than 50%, and the oil production has been increased to a certain extent.

     For example:

     Kong59-17H3 is located in an oil field, the reservoir depth is close to 2,000m, which is not applicable for electric heating technology. Because of the high viscosity and poor fluidity of crude oil, the wells can only produce water but no oil. So the daily production water is 26m3/d, the daily production oil is only 0.3 m3/d, and the water content is 98%.Kong59-17H3 has been forced to close, which has been considered to have no exploitation value.

     Product solutions:

         1)  Flow rate required: the daily production is 2~10 m3/d, the Required pump setting depth up to 2000 m.

         2)  Prediction of dynamic fluid level: the reasonable submergence depth of the cavity pumping is generally over 300m, then according to the specific well conditions and other information, the maximum allowable dynamic fluid level is determined to be 1700m.

         3)  Selection of Screw Pump

                     a)  Determination of theoretical displacement

                         The reasonable speed of the submersible screw pump is 80~250 rpm, the output corresponding to the average speed of 150rpm should reach the target liquid production. For submersible screw pump, the rated displacement speed standard is 100 rpm, when the speed is 100rpm, the displacement is as follows:

                         10m3 / (150rpm / 100rpm) = 6.67 m3/d/100rpm.

                         So the theoretical displacement is 6.67 m3/d/100rpm.

                     b)  Calculation of Effective Lift Height      

                        The Effective Lift Height = pump setting depth + oil pressure translates into pressure head + tubing friction loss head – pump suction head.

                         This well requires a maximum lift of 2000m.

                     c)  Optimum Selection of Screw Pump Type

                         According to the above calculation, the effective lifting height and theoretical displacement of screw pump are obtained. So the optimum screw pump model is 6E2000, and its rated displacement is 5.5 m3/d/100 rpm and maximum lifting height is 2000 m, which can meet the design requirements of this well.

                         The pump performance curve is as follows:




4)  Selection of Motor

    According to the minimum driving torque of 130N.m and the motor table below, the preferred motor model is PMMLIFT-M-6.5. its input voltage is 380V, rated current is 15A, rated power is 6.5KW, rated torque is 250N.m. So it can meet the requirement of the screw pump torque.


5.  Product application effect and Problem solving

    This well was constructed in October 2017, replacing the mechanical oil production system with our company’s system. The daily oil output became 3.5m3/d, the water content was reduces to 84%. Outstanding energy saving and consumption reduction, has achieved good economic benefits. As shown in the figure below: 


For details, please visit  Hangzhou Qianjing Technology CO., LTD