The well discussed in this paper has a history of sand production and has exhibit long cyclic slugging behavior with a frequency of several days and reduced average production. The lower completion has a 2000-ft gap between the mule shoe and the packer that is exposed to the larger diameter of 7-in. liner. It is not fully understood whether the slugging is caused by the gap at the lower completion or by sand transportation or both.
Dynamic wellbore modelling with sand particle transport is essential to model the abovementioned complex slugging behavior. A stepwise approach was adopted to allow systematic evaluation of this complex slugging phenomenon. Initially, a lumped inflow with no sand transportation was assumed. In the next stage, sand transportation was included with zonal inflow details added. Several sensitivities on sand particle sizes, particle density, zonal productivity index, etc. were carried out, all of which were aimed at reproducing the long cyclic slugging behavior observed in the field.
Transient simulations successfully produced the slugging behavior observed in the field. Cyclic slugging was seen to be caused by the flow dynamics generated by particles of small to medium size. Some of the key findings were complete blockage by porous sand stationary bed at the lower completion gap (with subsequent pressure buildup), transition from stationary bed to moving bed, rate-dependent velocity of a slow-moving particle bed (eventually producing to surface), and fresh sand particle production from the reservoir at increased drawdown. Measured data from the sand detector confirmed the production of sand, particularly around the same period as predicted by simulation.
Potential slug mitigation solutions were established that should help to achieve higher and stable production. One solution was to achieve higher flow velocity and therefore enable sand transportation as a continuous moving bed (i.e., no blockage), such as reducing the gap size at the lower completion section together with either tubing size reduction or electric submersible pump (ESP) installation. The other solution was to implement an appropriate sand control/sand consolidation method.
Sand production is a common flow assurance issue and sometimes can result in unstable flow behavior causing reduced production. This work is the first attempt to implement particle transport modelling in transient multiphase flow simulation to successfully address a slugging issue in a real well. The analysis helped in understanding the mechanism causing the slugging and arriving at a potential mitigation solution. Further, it provides a step-by-step workflow and a template to address such problems.
Electrical-submersible-pump (ESP) technology is a proven artificial-lift method for shallow, low-pressure reservoirs such as those found in the West Sak viscous oil field in Alaska. This study examines how subsea processing (SSP) can develop into an important enabling technology for future ultradeepwater-field developments and long-distance tiebacks. Unconventional production patterns in the Permian Basin are leading producers to replace electrical submersible pumps (ESPs) with gas lift, which had been little used there. The sharp downturn in the offshore oil business has sparked interest in using subsea pumps to add production. If those conversations turn into orders, it may convert this rarely used option into a commonly used tool for extending the life of offshore fields.
PipeFractionalFlow, a spinoff startup from the University of Texas at Austin, uses new theories and equations to make modeling complex multiphase flow more affordable. A model recently developed offers operators an “independent and unbiased” way to validate the system and select candidate wells. Slug flow has made the life of an unconventional production engineer a bit complicated, but a new downhole technology may smooth things right out by solving some big artificial lift problems for the shale sector. This paper presents the results of a comprehensive multiphase-flow study that investigated the relationship between the principal stresses and lateral direction in hydraulically fractured horizontal wells. This work experimentally investigates the behavior of an intermittent multiphase liquid/gas flow that takes place upstream of an electrical submersible pump (ESP).
This paper presents the data collected by an ultrasound downhole scanner, demonstrating a novel method for diagnosing multilateral wells. Electrical-submersible-pump (ESP) technology is a proven artificial-lift method for shallow, low-pressure reservoirs such as those found in the West Sak viscous oil field in Alaska. The green light comes 4 years after the privately-held firm filed its development and production plan. Liberty Island would consist of gravel, stretch 9 acres, and sit just a few miles offshore. Major oil discoveries by Armstrong Oil & Gas and ConocoPhillips have compelled the US Department of the Interior to reassess its estimate of undiscovered, technically recoverable resources in parts of Alaska.
Installing an inappropriate or poorly specified ESP leads to lost production, short runlives, and ultimately higher production costs. With the growth in ESP-produced unconventional wells, appropriate ESP design becomes more challenging due to divergent HP and head requirement at initial production versus the depleted well at end of life. ESP design is typically performed by the ESP vendors (often with less than complete design data), reviewed by the production engineer, and then equipment selected and installed. The "Why?" and the "How?" of the design What well, production & facilities information is required to ensure a successful design Function and operation of each ESP component and how it impacts the application design Calculations and data that make up an effective ESP design ESP application design by hand and using software Single operating point and dual operating point designs Gas handling approaches with ESPs – functional limits Reviewing ESP designs – how to read the report ESP equipment specifications This course will empower Production Engineers to understand the correct equipment sizing for a well and enable the engineer to quality check the design report provided by the vendor. Upon completion of this course, participants will be able to perform a design and read a design report, comment on its applicability to the well’s operation, and know if the specified equipment will meet the well requirements.
Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. An artificial lift system that is powered by injected fluid (usually water), that powers a pump similar to the rotating pump used in electrical submersible pumps.
Proper sizing and selection of an electrical submersible pump (ESP) system is essential to efficient and cost-effective performance. Selection and sizing of proper ESP equipment for a particular application should be based on a nine-step design procedure. This nine-step procedure helps the engineer design the appropriate submersible pumping system for a particular well. Each of the nine steps is explained below, including gas calculations and variable-speed operations. Specific examples are worked through in ESP design. The design of a submersible pumping unit, under most conditions, is not a difficult task, especially if reliable data are available.