What's New in Artificial Lift
may 2011 / Defining Technology for Exploration, Drilling and Production / worldoil.com
INTELLIGENT WELLS AND FIELDS What’s new in artificial lift NOCs growing and evolving Deepwater drilling advances ® Excerpts are from an article that originally appeared in World Oil MAY 2011 issue, pgs 73-83. Posted with permission.
PRODUCTION TECHNOLOGY What’s new in artificial lift
Recent developments cations in the tubing along with pressure system run life. Additionally, having the are introduced in beam/ and temperature. Also, a three-in-one backup option helps to minimize deferred rod pumping, electrical plunger combines increased efficiency, production and also allows for improved submersible pumping, gas pressure actuation for sandy conditions, workover scheduling. and improved lubrication. Also present- Many countries impose regulations lift, gas well dewatering and ed is a high-pressure, cold-weather lubri- requiring independent production of flu- artificial lift monitoring. cator developed to comply with the same ids from different producing zones. The standards and requirements as other dual ESP system provides a means to wellhead components. comply with such regulations by produc- ŝŝ JAMES F. LEA, PL Tech LLC; and HERALD To monitor artificial lift system perfor- ing multiple zones either independently W. WINKLER, Texas Tech University mance, a proprietary interpretation tech- or simultaneously. This is achieved by nique provides real-time flowrate without running either one or both of the ESPs the need to retrofit additional hardware in in the dual ESP system. For multizone Presented here are 18 recent technolo- the field, with the exception of downhole production applications, the system gy developments in artificial lift equipment ESP gauges and SCADA. Also discussed uses two ESPs, one of which is housed and software associated with artificial lift. is a flexible ESP monitoring, surveillance in a pod that includes a tailpipe string New offerings related to beam and rod and production optimization tool. Anoth- and seal assembly and is located in a seal pumping include an improved downhole er company has combined computerized bore packer situated between perforated separator for placement in the near-verti- analysis of dynamometer records with zones. The pod-and-packer configura- cal section of a horizontal well producing powerful portable computers, advanced tion isolates the producing zones. An gas and some liquids. An improvement in modeling software and wireless data ac- upper ESP, which is installed above the materials is discussed for a device to pre- quisition to allow visualization of rod pod, includes a bypass and produces the vent pump sanding, as well as a pump de- pump operation in real time. upper zone. Fluids from each zone are signed for sandy wells, and an adjustable Finally, a novel pumping system is pre- produced independently to the surface threaded polished rod is presented that sented that combines the advantages of through the use of two tubing strings in- allows for safer and simpler spacing of the beam pumping and ESP systems. stalled concentrically. downhole sucker rod pump. Both pumps are fully instrumented, Among ESP-related advances, a dual ELECTRICAL SUBMERSIBLE and they also measure operational and ESP system provides either a backup in PUMPING production parameters for each pump the case of primary pump failure or an The push by E&P companies into and zone. The arrangement allows each improved solution for multizone pro- increasingly challenging production en- ESP to be sized and operated optimally duction. Enhanced modeling software vironments worldwide has created an for its zone. A dual concentric tree pre- is presented that assists in the design of expanding market for electrical submers- vents the commingling of production at ESP and gas lift systems. A number of ible pumps that provide additional func- surface. Additionally, it is possible to shut improvements in one supplier’s pump tionality, as well as tools to increase the down one zone without affecting produc- stage portfolio are discussed, as well as an functionality of existing ESPs. tion from another. elevated-temperature ESP for SAGD ap- Dual ESP system. Schlumberger’s Modeling software update. In 2010, plications and an ESP deployment system dual ESP system features a variable con- Schlumberger updated its Avocet Well that allows pulling and replacement with- figuration that provides additional func- and Surface Modeler software with the out a workover rig. tionality, specifically for ESP backup and release of its WSM 2010.1 software pack- Gas lift-related advances discussed are multizone production requirements. The age, which provides a comprehensive de- a valve plug that dissolves in saltwater, company has installed more than 100 sign solution for ESP and gas lift systems. to eliminate the need to remove dummy dual ESP systems in a wide variety of ap- The 2010 release includes an intuitive valves in new gas lift systems, and two plications, including on- and offshore, for workflow that allows users to navigate new check systems for 1½-in.-OD gas both backup and multizone ESP applica- through the application design in a logical lift valves and for use on a recently intro- tions, Fig. 4. and concise manner. duced mandrel. The backup functionality allows op- Enhanced reporting features allow Within the topic of gas well dewater- erators to minimize time-consuming and for the reformatting and improvement ing, a new instrumented plunger deter- costly workovers in the event of a primary of all reports, as well as improved report mines location by sensing the collar lo- ESP failure, while also extending the ESP loading times and customization options
World Oil / may 2011 73 PRODUCTION TECHNOLOGY
also includes additions for surface power proved hydraulic efficiency, as well as gas- Fig. 4. Schlumberger dual ESP system in backup (left) and multizone configurations. source calculations and added support for and abrasives-handling capacities, unlike user-specified inflow performance rela- radial flow stages that are normally used tionship curves. for similar production rates. The ESP design module provides a All REDA pumps with new stages comprehensive well performance analy- are assembled in compression factory- sis solution for a complete ESP system shimmed design. This feature ensures that design. The software uses fluids, well and the pump shafts are precisely matched reservoir data to predict the inflow and at the factory to enable the axial thrust outflow performance of an ESP design. It transfer directly to the high-load protec- sizes and analyzes an entire ESP system, tor bearing, eliminating time-consuming with the goal to optimize pump design and error-prone field shimming proce- and greatly increase run life for increased dures. Combined with Maximus motors production. The software package also and factory-shimmed Maximus protec- provides a comprehensive selection of tors, factory shimming of pumps reduces fluid models and correlations to match ESP installation time requirements by at measured well data. An extended set of least 60%, while also protecting the qual- empirical and mechanistic flow correla- ity and integrity of the system by eliminat- tions is also available, allowing users to ing human and weather-related factors. match field performance. Installation and reliability im- GAS LIFT provements. Recently, Schlumberger New components and modeling soft- revamped its ESP volume stage portfolio ware continue to increase both the ef- and released a number of new stages that fectiveness of the gas lift method and its increase hydraulic efficiency and lift capa- applicability to a widening variety of arti- bility in its REDA line of ESPs. The com- ficial lift applications. pany’s new stage development process Modeling software update. Already uses computational fluid dynamics mod- discussed in the context of its ESP design eling and prototype performance verifi- module, Schlumberger’s updated Avo- cation to optimize internal stage geom- cet Well and Surface Modeler software etry and flow profiles in order to produce (WSM 2010.1) also has new features maximum possible efficiency and lift. specifically for gas lift systems. These Higher hydraulic efficiency directly include improved calculations for test results in reduced motor horsepower rack opening pressure, deepest injection requirements and total power consump- point (DIP) and minimum valve spac- tion for an application, allowing for sig- ing. The default design module has been nificant savings to the total cost of own- changed from the injection-pressure- ership of an ESP system. operated (IPO) surface close to the IPO Among the latest ESP stage devel- minimum/maximum design. Addition- opments is the D1050N stage, which ally, the new software package includes is now the smallest and most efficient improved DIP plot interactivity, with mixed-flow geometry stage in the REDA data modification and additional vari- line for wells with approximately 1,000- ables added for sensitivity analysis and for content and plots. The application bpd production rates, Fig. 5. Wider vane case comparisons. database has also been changed, provid- openings and smoother flow patters allow The gas lift design module is intended ing trouble-free installation and smooth the mixed-flow geometry to provide im- to help operators optimize gas injection operation with Windows Vista and Win- depth, minimize downtime through con- dows 7 32-bit and 64-bit operating sys- Fig. 5. Schlumberger D1050N mixed-flow tinuous gas lift operation, and maximize tems. Other changes include improved geometry ESP stage. production through best-suited gas lift viewing in Vista and Windows 7 operat- equipment selection. The software defines ing systems with updated color schemes the wellbore schematic and accurately siz- and fonts, and a revamped help system es all downhole components. A compre- and tutorials. hensive database of components includes For ESPs, the software has been greatly the most recent gas lift equipment. enhanced, with an updated equipment da- tabase including new pumps and variable MONITORING PERFORMANCE speed drives (VSDs). Users will experi- Operators are increasingly demanding ence an easier definition and better mod- real-time data and analysis to help them eling of pressure loss and heat transfer optimize their use of pumping systems, for shrouds and pods. The 2010 release driving suppliers to offer more advanced
74 may 2011 / WorldOil.com PRODUCTION TECHNOLOGY
JAMES F. LEA teaches courses diagnostic tools for artificial lift. making another means of flowrate deter- in artificial lift and production Real-time flowrates. In 2010, mination necessary. for Petroskills. He holds BS and MS degrees in mechanical Schlumberger introduced a proprietary When downhole measurements are engineering from the University interpretation technique to provide real- used, it is possible to plot flowrate, flow of Arkansas and a PhD from time flowrate data without the need to pressures and reservoir pressure accu- Southern Methodist University. He worked for Sun Oil as a retrofit additional hardware in the field, rately, which allows engineers to see pro- research engineer from 1970 to 1975, taught at with the exception of downhole ESP duction changes as small as about 10 bpd. the University of Arkansas from 1975 to 1978, was team leader of production optimization gauges and a SCADA system, which in Enhanced superposition analysis can be and artificial lift atA moco EPTG from 1979 many cases is already available. Through used to monitor real-time reservoir pres- to 1999 and was chairman of Texas Tech the use of this real-time flowrate data, sure based on flowing pressure, reducing University’s petroleum engineering department back allocation can be improved. the need for frequent buildups. from 1999 to 2006. Real-time flowrate data represents To accommodate the advances pro- HERALD W. WINKLER is a step-change in measurement over the vided by this new real-time flowrate former chairman and now a professor emeritus and once-a-month testing with manual data technique, the company’s LiftWatcher research associate in Texas entry that is typical in wells that are not real-time surveillance service now hosts Tech University’s petroleum equipped with dedicated multiphase data from rod pumps, progressive cavity engineering department located in Lubbock, Texas. meters. The granularity provided is par- pumps and vortex flowmeters, as well as He also works as a consultant ticularly important in wells where pro- the previously supported ESPs and hy- to the oil and gas industry in artificial lift, duction fluctuates rapidly. Furthermore, draulic production systems. This over- specializing in gas lift. many reservoirs produce at flowrates haul allows operators to have a better in- below the threshold required to achieve sight into the entire infrastructure rather reasonable accuracy with test separators, than just portions of it.
Article copyright © 2011 by Gulf Publishing Company. All rights reserved. Printed in U.S.A. World Oil / maY 2011 75 Not to be distributed in electronic or printed form, or posted on a website, without express written permission of copyright holder.