Сравнение технологий ЭЦН для работы с большим содержанием газа в насосе на основе промысловых испытаний Бедрин В.Г. ООО «РН-Пурнефтегаз», Хасанов М.М., Хабибуллин Р.А., Краснов В.А., Пашали А.А. ОАО НК «Роснефть», Литвиненко К.В., Еличев В.А. ООО «РН-УфаНИПИнефть», Прадо М. Университет Талса Авторское право 2008 г., Общество инженеров-нефтяников Этот доклад был приготовлен для предъявления в 2008 Российской нефтегазовой технической конференции и выставке состоится в Москве 28-30 октября 2008.Данный доклад был выбран для проведения презентации Программным комитетом SPE по результатам экспертизы информации, содержащейся в представленном авторами резюме. Экспертиза содержания доклада Обществом инженеров-нефтяников не выполнялась, и доклад подлежит внесению исправлений и корректировок авторами. Материал в том виде, в котором он представлен, не обязательно отражает точку зрения Общества инженеров-нефтяников, его должностных лиц или участников. Доклады, представленные на конференциях SPE, подлежат экспертизе со стороны Редакционных Комитетов Общества инженеров-нефтяников. Электронное копирование, распространение или хранение любой части данного доклада в коммерческих целях без предварительного письменного согласия Общества инженеров-нефтяников запрещается. Разрешение на воспроизведение в печатном виде распространяется только на резюме длиной не более 300 слов; при этом копировать иллюстрации не разрешается. Резюме должно содержать явно выраженную ссылку на то, где и кем был представлен данный доклад. Write Librarian, SPE, P.O.Box 833836, Richardson, TX 75083-3836 U.S.A., факс 01-972-952-9435. РезюмеОдним из ограничений эксплуатации электрических погружных центробежных насосов (ЭЦН) является наличие свободного газа в жидкости, перекачиваемой насосом. Увеличение его объемной доли снижает перепад давления, развиваемый насосом, приводит к нестабильной работе, снижению потенциала добычи нефти, преждевременным отказам оборудования.ЭЦН являются основным способом добычи нефти в России и, по мере истощения запасов нефти, применяются во все более сложных геологических условиях. В совокупности с интенсификацией добычи нефти это приводит к эксплуатации ЭЦН на пределе технических возможностей работы со свободным газом. Работа на пределе повышает требования к пониманию процессов, происходящих в ЭЦН, и увеличивает цену ошибки при дизайне оборудования. Критически важной становится информация о величине технического предела различных технологий ЭЦН.Получение информации о техническом пределе является само по себе сложной задачей. В условиях заводов-производителей на испытательных стендах трудно достичь условий, эквивалентных условиям в скважине (высокие температуры и давления, использование реальных пластовых флюидов), и предел, полученный производителем на стенде, может значительно отличаться для реальной скважины. Детальное математическое описание процессов многофазного потока в сложной системе пласт-насос-скважина также довольно сложно и требует больших затрат ресурсов и времени. Выходом является комбинация современных методов инжене...

Monitoring and testing of subsurface equipment is crucial when stepping up artificial lift efficiency. Oil production using electrical submersible pumps (ESP) in RN-Purneftegas was initially complicated by a strong gas influence. The main method to increase ESP performance in wells with a high GOR is using rotary gas separators. Subsurface equipment adjustment for high GOR conditions, including gas separator calibration, is of primary importance, due to a strong influence of the ESP design on well performance. To perform the corresponding calculations, appropriate data is necessary. Currently, there are many tools and measurement devices for oil production monitoring and controlling, however, it is impossible to use its data without a good understanding of all the parts of the "reservoir-well-pump" production chain. The artificial lift team formed under Rosneft's New Technology System program conducted a wide range of field tests. The main goal of such tests was gathering information for parameter analysis and proper timing of ESPs with malfunctions in rotary gas separators. The collected information about real field performance was then used for validation of the accuracy of the lab data for gas separator performance, acquired by Russian State Oil&Gas University. It was concluded that the gas separator performance data obtained in laboratory if combined with correlation for natural separation prediction can be used for total separation efficiency estimation. The test results allowed us to estimate the potential for oil production increase at over 700 tons per day in Purneftegas. Importance of separation efficiency for well performance A number of geological and technical factors such as pump performance acquired in lab tests with a single phase fluid (typically water), or well operation history are used in ESP calibration. However, gas separator performance had not been adequately modeled during previous ESP sizing. The separator was treated as an intake module with constant separation efficiency in most cases.

The goal of present study was to develop and test a new algorithm to selection proper artificial lift method for heavy oil production with sand control. We developed a Matrix of technologies for such oilfields using operating experience worldwide. For selected methods we defined production characteristics using Technology Application Template -a special tool which determines the most profitable artificial lift system based on net present value criteria. Solutions were implemented in North Komsomolskoe field located in Western Siberian basin.Before performing calculations we defined the following: Oilfield characteristics Well parameters Limitations of artificial lift methods Operational expenses for each artificial lift method Recommended methods were tested on vertical wells of North-Komsomolskoe oilfield pilot area and on remote horizontal well in the north part of the field. The highest rate was reached using progressing cavity pump on horizontal well. On vertical wells of pilot low productivity area gaslift and hydraulic jet pump (which are economicaly efficient) have been successfully tested.This paper describes combined analytical and operational approach for complicate field development.

One of limitations of achieving full potential in pumped wells is due to the presence of excessive free gas at pump intake. The presence of free gas at pump intake has several effects on the pump performance. A reduction in the pressure drop developed by the pump is usually observed when pumping multiphase flow mixtures. This performance reduction sometimes may be severe, resulting in unstable pump operation, production losses and may lead to premature equipment failure.Electric submersible centrifugal pumps (ESP) are commonly used in Russia and other parts of the world for oil production. Currently operators are being required to produce wells under non conventional and challenging operational conditions. One of such conditions is the use of ESP in wells with a high free gas liquid ratio that requires the use of special technology. Under those circumstances it is very important to understand more profoundly the processes of ESP operation as any mistake in the equipment design may have severe economical consequences. One of the crucial information needed is the technical limiting operational conditions for different ESP technologies when handling high gas liquid ratio mixtures.Determination of the technical operational envelope is itself a challenge. Experimental work conducted in Universities and industry research centers are very important for an understanding of the problem and advance of the technologies. But it is difficult to recreate in the lab the same conditions that exist in a well bore. Working with actual fluids at high temperatures and pressures are still challenging conditions to be reproduced in the lab. Therefore theoretical models, experimental correlations manufactures technical guidelines need to be verified against the conditions existing in a real oil well.This work presents the conclusions of the use of state of the art engineering methods describing the reservoir-pumpproduction system to analyze the performance of gas handling technologies based on real well field test results. The field tests were conducted under the New Technologies System project of Rosneft Oil Company. Field tests estimated technical limits for ESP gas handling technologies for up to 75% of volumetric gas fraction at pump intake conditions, as well as confirmed the possibility of oil production enhancement with the tests (the NPV for 11 ESP tested was more than 40 mln. rubles in 2007). It is estimated that more than a 100 wells would benefit from ESP gas handling technologies in Purneftegas alone, yielding significant economic impact for the company, increasing oil production by more than 700 tons/day. Review of gas handling approachesTypically, wells with high GLR are produced by natural flow until conditions require an artificial lift system. At this point, gas lift is usually chosen as an artificial lift method unless some of the free gas can be separated and vented allowing the use of a conventional pump. The performance of ESPs under two phase flow conditions depends on factors such as liquid flow rate, amount of f...

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