scholarly journals New correlations for predicting two-phase electrical submersible pump performance under downhole conditions using field data

Author(s):  
Thuy Chu ◽  
Tan C. Nguyen ◽  
Jihoon Wang ◽  
Duc Vuong

AbstractElectrical Submersible Pump (ESP) is one of the major Artificial Lift methods that is reliable and effective for pumping high volume of fluids from wellbores. However, ESP is not recommended for applications with high gas liquid ratio. The presence of free gas inside the pump causes pump performance degradation which may lead to problems or even failure during operations. Thus, it is important to investigate effect of free gas on ESP performance under downhole conditions. At present, existing models or correlations are based on/verified with experimental data. This study is one of the first attempts to develop correlations for predicting two-phase gas–liquid pump performance under downhole conditions by using field data and laboratory data. Field data from three oil producing wells provided by Strata Production Company and Perdure Petroleum LLC. as well as experimental data obtained from experimental facility at Production and Drilling Research Project—New Mexico Tech were used in this study. Actual two-phase pump differential pressure per stage is obtained from experiments or estimated from field data and was normalized using pump performance curve. The values are compared to pump performance curve to study the relationships between pump performance and free gas percentage at pump intake. Correlations to predict ESP performance in two-phase flow under downhole and experimental conditions was derived from the results using regression technique. The correlation developed from field data presented in this study can be used to predict two-phase ESP performance under downhole conditions and under high gas fraction. The results from the experimental data confirm the reliability of the developed correlation using field data to predict two-phase ESP performance under downhole conditions. The developed correlation using the laboratory data predicts quite well the two-phase pump performance at the gas fraction of less than 15% while it is no longer reliable when free gas fraction is more than 15%. The findings from this study will help operating companies as well as ESP manufacturers to operate ESPs within the recommended range under downhole conditions. However, it is recommended to use the proposed correlation on reservoirs with conditions similar to those of the three presented wells.

Author(s):  
Diana Marcela Martinez Ricardo ◽  
German Efrain Castañeda Jiménez ◽  
Janito Vaqueiro Ferreira ◽  
Pablo Siqueira Meirelles

Various artificial lifting systems are used in the oil and gas industry. An example is the Electrical Submersible Pump (ESP). When the gas flow is high, ESPs usually fail prematurely because of a lack of information about the two-phase flow during pumping operations. Here, we develop models to estimate the gas flow in a two-phase mixture being pumped through an ESP. Using these models and experimental system response data, the pump operating point can be controlled. The models are based on nonparametric identification using a support vector machine learning algorithm. The learning machine’s hidden parameters are determined with a genetic algorithm. The results obtained with each model are validated and compared in terms of estimation error. The models are able to successfully identify the gas flow in the liquid-gas mixture transported by an ESP.


2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Lissett Barrios ◽  
Mauricio Gargaglione Prado

Dynamic multiphase flow behavior inside a mixed flow electrical submersible pump (ESP) has been studied experimentally and theoretically for the first time. The overall objectives of this study are to determine the flow patterns and bubble behavior inside the ESP and to predict the operational conditions that cause surging. The theoretical study includes a mechanistic model for the prediction of the flow behavior inside the pump. The model comprises a one-dimensional force balance to predict occurrence of the stagnant bubbles at the channel intake. This model depends on two important variables, namely the stagnant bubble size and the bubble drag coefficient. The bubble size has been measured and a physically based correlation is presented. A new correlation for the drag coefficient is proposed as a function of rotational speed and Reynolds number. The model enables the prediction of the operational envelope of the ESP, namely the transition to surging.


2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Rinaldo Antonio de Melo Vieira ◽  
Mauricio Gargaglione Prado

The effect of free gas on electrical submersible pump (ESP) performance is well known. At a constant rotational speed and constant liquid flow rate, a small amount of gas causes a mild head reduction when compared to the single phase liquid head. However, at higher gas rates, a drastic reduction in the head is observed. This critical condition, known as the surging point, is a combination of liquid and gas flow rates that cause a maximum in the head performance curve. The first derivative of the head with respect to the liquid flow rate changes sign as the liquid flow rate crosses the surging point. In several works on ESP two-phase flow performance, production conditions to the left of the surging region are described or reported as unstable operational conditions. This paper reviews basic concepts on stability of dynamical systems and shows through simulation that ESP oscillatory behavior may result from two-phase flow conditions. A specific drift flux computation code was developed to simulate the dynamic behavior of ESP wells producing without packers.


Author(s):  
Lissett Barrios ◽  
Mauricio Gargaglione Prado

Dynamic multiphase flow behavior inside a mixed flow Electrical Submersible Pump (ESP) has been studied experimentally and theoretically for the first time. The overall objectives of this study are to determine the flow patterns and bubble behavior inside the ESP and to predict the operational conditions that cause surging. An experimental facility has been designed and constructed to enable flow pattern visualization inside the second stage of a real ESP. Special high speed instrumentation was selected to acquire visual flow dynamics and bubble size measurements inside the impeller channel. Experimental data was acquired utilizing two types of tests (surging test and bubble diameter measurement test) to completely evaluate the pump behavior at different operational conditions. A similarity analysis performed for single-phase flow inside the pump concluded that viscosity effects are negligible compared to the centrifugal field effects for rotational speeds higher than 600 rpm. Therefore, the two-phase flow tests were performed for rotational speeds of 600, 900, 1200, and 1500 rpm. Results showed formation of a large gas pocket at the pump intake during surging conditions.


2003 ◽  
Vol 125 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Hitoshi Fujimoto ◽  
Satoshi Ogawa ◽  
Hirohiko Takuda ◽  
Natsuo Hatta

The pump performance of a small air-lift system for conveying solid particles is investigated experimentally. The total length of the vertical lifting pipe is 3200 mm, and the inner diameter of the pipe is 18 mm. The gas injector is set at a certain point of the pipe. The flows in the lifting pipe are water/solid two-phase mixtures below the gas injection point, and air/water/solid three-phase mixtures above it. The time-averaged characteristics of the flows are examined for various experimental conditions. The effects of particle diameter, particle density, the gas-injection point, and the volume flux of air on the pump performance are studied systematically. The critical boundary at which the particles can be lifted is discussed in detail based upon one-dimensional mixture model.


Author(s):  
Emanuel Marsis ◽  
Sahand Pirouzpanah ◽  
Gerald Morrison

Computational fluid dynamics (CFD) is widely used to simulate fluid flows in turbomachinery. A detailed CFD study was performed to enhance the design of an electrical submersible pump (ESP) manufactured by Baker Hughes. The pump has a special patented impeller design enabling it to handle up to 70% gas volume fraction (GVF). A CFD-based design study was performed on the ESP diffuser (for the first time) to improve the pump’s performance and reduce losses. The CFD model was initially validated using experimental results. Different designs were simulated to reach the optimum design. Many factors affect pump performance, including flow separation losses in the stator (such as the number of blades, the meridional profile of the pump and the shape of the stator blades). In addition, a non-uniform flow while exiting one stage affects the rotor performance of the next stage. Therefore, improving the diffuser design improves the current stage performance as well as the performance of the next rotor. In this study, improved designs show that optimizing the stator design can increase the static pressure of the pump by 4% for single-phase flow, and 23% for two-phase flow in the simulated cases.


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