Electrical Submersible Pump Installations Research Articles

Permanent Magnet Motors Help Reduce Carbon Footprint in Artificial Lift Systems

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 209736, “Carbon-Footprint Reduction Using Permanent Magnet Motors in Artificial Lift Systems,” by Luis F. Ararat, Ronald F. Herrera, and Sergio A. Parra, SierraCol Energy, et al. The paper has not been peer reviewed. _ Permanent-magnet-motor (PMM) technology was evaluated and implemented in the different artificial lift systems in the Llanos Norte (LLN) and La Cira Infantas (LCI) fields in Colombia, aiming to find a more-efficient motor to generate energy consumption savings and reduce carbon footprint. The complete paper shares technical details of the evaluation of tests performed in the field to validate the implementation of PMM technology in the artificial lift systems, the calculation of reduction of tons of carbon dioxide (CO2), and the main challenges in its application as an energy-efficient solution for future projects. Field Background The Llanos Orientales basin has 482 installed electrical-submersible-pump (ESP) and 24 sucker-rod-pump (SRP) wells at the time of writing, at an average depth of 7,450 ft true vertical depth (TVD). LCI, the other field under study, is Colombia’s first producing field and has three different artificial lift systems to produce its wells: 215 progressive-cavity-pump (PCP) installations, 691 SRP installations, and 257 ESP installations. The average depth of the field is 3,500 ft TVD. Background for PMM Technology in the Operator’s Energy Fields In 2016, the first attempt to implement PMM technology for ESP equipment in the LLN and LCI fields was made. The project began in November of the same year with a trial test in LLN with the installation of PMMs in two ESP wells. During the next 2 years, the testing conditions were adjusted, resulting in an energy-savings average of 15%, which validated its large-scale implementation, with more than 250 installations in LCI and LLN. Given the results obtained with ESP installations, the implementation of PMMs was considered for the PCP systems on the surface. The trial test began in 2019 by installing PMMs in two PCP wells in LCI, resulting in a 35% energy savings. The promising results spurred large-scale implementation in PCP initial completions since 2021. At the time of the paper’s writing, 12 wells have been installed. The field trial for SRP systems ran from 2020 to 2021, seeing the installation of five wells in LCI with an average energy savings of 18%. Applications of PMM Technology in Artificial Lift Systems ESP PMM. The ESP PMM features permanent magnets mounted in the rotor. The rotor flux is supplied by the magnets and therefore does not require an electrical power supply to generate this magnetic field. Permanent magnets installed in the motor rotor provide key advantages: - By only using energy to generate the magnetic field in the stator, less energy is required for PPM operation. - Slippage in magnetic flux between rotor and stator is zero. - High efficiency (90–93%) over a wider operating range is achieved. - Higher power density is seen than in conventional rotors. - Electrical losses are reduced, a lower operating current is used, and less heat generation is experienced.

SAGD ESP Installations in Canada

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 110103, "Pushing the Boundaries of Artificial-Lift Applications: SAGD ESP Installations in Canada," by F. Gaviria, SPE, Suncor, and R. Santos, SPE, O. Rivas, SPE, and Y. Luy, Schlumberger, originally prepared for the 2007 SPE Annual Technical Conference and Exhibition, Anaheim, California, 11–14 November. The paper has not been peer reviewed. The need for high-temperature electrical-submersible-pump (ESP) systems is growing as the oil industry matures. Canada's nonconventional oil reserves are estimated at more than 1 trillion bbl and Suncor's heavy-oil reserves in northern Alberta, Canada, are estimated to have a potential production of 14 billion bbl of crude oil, but the traditional mining methods of recovery do not make them all economically reachable. It is estimated that less than one-fifth of the oil-sands resource is mineable. To deal with this, Suncor has turned to in-situ steam-assisted gravity-drainage (SAGD) operations as a key part of its plans to increase bitumen supply to its upgraders. Heavy-Oil and Oil-Sands Resources The Canadian petroleum industry is facing dwindling light-crude-oil reserves. However, at the same time, an abundance of established heavy-oil and bitumen deposits remains virtually untapped. According to government statistics, Canada's oil sands contain nearly 175 billion bbl of crude-oil reserves that can be processed with today's technology, thus putting the oil sands second only to Saudi Arabia in crude-oil reserves. It is thought that further technological improvements would allow the recovery of more than 350 billion bbl of bitumen. The Alberta Energy and Utilities Board estimates annual bitumen production in Canada will more than double from 1.1 million B/D (December 2005) to 2.6 million B/D by 2014. Currently, bitumen and synthetic-oil production represents approximately 50% of Canada's total crude output. Three major deposits of bitumen, also called oil sands, are found in the province of Alberta, Canada. These deposits are the Athabasca, Peace River, and Cold Lake oil sands. Despite the technical challenges of producing and processing bitumen, several factors have made investments in oil sands very attractive, given world oil prices. There are no "finding costs" because the oil sands are well delineated, there is ready access to the largest market in the world (the US) by established pipelines, and new technology has reduced operating cost by at least a factor of two. Surface Mining The Athabasca oil-sand deposits occur from the surface to a depth of 750 m true vertical depth. Surface-mining exploitation at depths of up to 100 m historically has been the technique commonly used by several producers in the area. This form of exploitation and development goes back to 1967 when Suncor Energy (Great Canadian Oil Sands then) started the construction of the first oil-sands commercial-mining and -production operation. Since then, more than 3 billion bbl has been produced. This successful story has required the development and improvement of technology such as truck-and-shovel cold-water extraction, slurry pipelining, mechanical separation, and the potential recovery of byproducts.

Two-Phase Flow Modeling of Inducers

Inducers, which are classified as axial flow pumps with helical path blades, are used within rotary gas separators commonly used in electrical submersible pump installations. A two-phase flow model has been developed to study the inducer performance, focusing on head generation. The proposed model is based on a meridional flow solution technique and utilizes a two-fluid approach. The model indicates that head degradation due to gas presence is a function of flow pattern. The effect of flow pattern diminishes when the void fraction is greater than 15 percent since the centrifugal force dominates the interfacial drag force. In this case, the two-phase flow can be approximated as a homogeneous mixture. The model also suggests that a liquid displacement correction is needed when phase segregation occurs inside the inducer. The new model significantly improves the ability to predict separation efficiency of a rotary gas separator over existing models. Hydrocarbon-air and water-air experimental data were gathered to validate the new model.

Numerical Simulation of the Gas-Liquid Flow in a Rotary Gas Separator

The presence of free gas at the pump intake adversely affects the performance of an electrical submersible pump (ESP) system, often resulting in low efficiency and causing operational problems. One method of reducing the amount of free gas that the pump has to process is to install a rotary gas separator. The gas-liquid flow associated with the down hole installation of a rotary separator has been investigated to address its overall phase segregation performance. A mathematical model was developed to investigate factors contributing to gas-liquid separation and to determine the efficiency of the separator. The drift-flux approach was used to formulate this complex two-phase flow problem. The turbulent diffusivity was modeled by a two-layer mixing-length model and the relative velocity between phases was formulated based on published correlations for flows with similar characteristics. The well-known numerical procedure of Patankar-Spalding for single-phase flow computations was extended to this two-phase flow situation. Special discretization techniques were developed to obtain consistent results. Special under relaxation procedures were also developed to keep the gas void fraction in the interval [0, 1]. Predicted mixture velocity vectors and gas void fraction distribution for the two-phase flow inside the centrifuge are presented. The model’s predictions are compared to data gathered on a field scale experimental facility to support its invaluable capabilities as a design tool for ESP installations.