specialist and dual esp completions
Production from wells with a single ESP can be limited by factors including amount of horsepower attainable downhole, maximum available ESP flow rate, high workover costs, casing corrosion considerations and limited control of production zones. Zenith specialise in engineering multiple ESP completions which overcome these constraints.
Each Zenith specialist completion system is designed to suit the specific requirements of the operator, based on their well parameters and production objectives. Systems include unique features which address problems inherent in alternative equipment, addressing the following constraints that can occur with standard ESP deployment:
- Reduce downtime and lifetime intervention costs
- Increase draw-down in constrained well geometries
- Improve zone management and contribution: two wells in one
- Casing Protect
- Parallel
- Dual Back Up
- Dual Boost
- Dual Zone
- Downloads
CASING PROTECTION ESP SYSTEM
For casing integrity issues and corrosive fluids. 
The ESP system is housed in a pod which is stabbed into a lower packer. The pod and packer isolate the upper casing from the well fluid, protecting it from corrosive well fluids. The pod enables the ESP to produce from below the packer by routing well fluid directly into the intake of the pump via the sealed pod unit. The pod has a penetrator system incorporated in the pod hanger to allow the ESP cable to exit through a pressure-tight connection. Multiple pods may be deployed to provide redundancy in the event of ESP failure.
SYSTEM BENEFITS
- Protect casing from corrosive well fluids
- Protect ESPs during deployment
PARALLEL ESP SYSTEM
For wells with high productivity indexes.
The parallel system uses two electrical submersible pumps to maximise flow rate where a single ESP would not be capable of handling the well potential rate due to casing size, pump rate or power supply constraints. Production from two ESPs is combined at the Y-block in the upper ESP bypass assembly. The bypass assembly suspends the lower ESP on its bypass tubing. Each ESP can produce to the surface independently at a reduced rate in the event that a pump should prematurely fail. This allows continued production, albeit at a lower rate, until workover is feasible.
SYSTEM BENEFITS
- Achieve maximum flow rates
DUAL BACK-UP ESP SYSTEM
For wells with high workover costs.
In the event of ESP failure, a back-up ESP already deployed in the well can be immediately turned on to maintain production. The second ESP is suspended below the upper ESP with a bypass assembly. Bypass tubing provides a production path for the lower ESP. Normally the upper ESP is run first to prevent temperature effecting backup system runlife. The lower ESP can be appropriately sized to accommodate changes in well performance such as decreasing reservoir pressure or increasing water cut.
Replace the Y-Block with the Zenith Auto Flow-Through (AFT) tool for automatic switching between upper and lower ESPs. The AFT also prevents circulation from upper to lower ESP and vice-versa, and protects pumps from descending solids on shut-down.
SYSTEM BENEFITS
- Minimise lifetime intervention costs
- Reduce downtime and deferred production when ESP failure occurs
DUAL BOOST ESP SYSTEM
For wells with lower productivity indexes.
Two ESPs are combined in series, sharing the number of stages and required horsepower. Pods are used to configure two ESPs in series, the lower ESP boosting the intake pressure of the ESP above it. The configuration enables two smaller ESPs to perform the job where a single large ESP would normally be infeasible due to casing size, horsepower or shaft strength limitations.
If a single pump will not produce to surface then a third ESP can be included in the completion as a redundancy measure for the failed pump. The Zenith Auto Flow Valve ensures lower pumps can be run without having to produce through the upper pump stages. The valve opens and closes automatically depending on which ESP is running.
SYSTEM BENEFITS
- Achieve maximum draw-down
DUAL ZONE ESP SYSTEM
For multiple zone wells requiring zonal control.
Dual zone completions enable production from multiple zone wells. A dedicated ESP for each zone gives independent control of draw-down allowing improved zone management, improved water management, preventing cross-flow between zones, and enabling individual production well tests on each zone independently. If used effectively during field planning, these systems can decrease number of wells required.
Dual zone systems are available in two configurations:
COMMINGLING SYSTEMS
Combines production from dedicated ESPs for upper and lower zones.
DUAL CONCENTRIC SYSTEMS
Dedicated ESPs for upper and lower zones that isolate zone contribution to surface production facilities.
SYSTEM BENEFITS
- Enables simultaneous production of incompatible fluids from separate zones
- Prevents water coning, maintaining well asset viability
- Allows simultaneous production and injection through a single well bore
- Reduces topside separator capacity requirement
- Drill fewer wells
- Test zones independently
- Reduced deferment: the second ESP provides back-up should one system fail
DUAL ZONE BACK-UP ESP SYSTEM
For high workover cost wells requiring access.
In the event of an ESP failure, a back-up ESP already deployed in the well can be immediately turned on to maintain production. The second ESP is suspended below the upper ESP with a bypass assembly. The bypass tubing provides a production path for the lower ESP with the third leg allowing wireline access for logging operations.
Normally the upper ESP is run first to prevent temperature effecting the backup system runlife. The lower ESP can be appropriately sized to accommodate changes in well performance such as decreasing reservoir pressure or increasing water cut.
SYSTEM BENEFITS
- Back-up ESP with access below the pumps
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SPECIALIST COMPLETIONS: GENERIC & BESPOKE SYSTEM DESIGN
In addition to the introductory brochures listed above, detailed information and specifications are available in our online e-catalogue.
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