Single ESP With Y-Tool And Pump Support
System 03: Y-Tool Completions
- Tailpipe Tubing Connection
- Handling Sub
- Pump Support Block
- Spear
- Handling Sub
- ESP Gauge
- Flush Joint Bypass Tubing
- ESP Motor
- Bypass Tubing Clamp
- MLE Cable
- ESP Seal Protector
- ESP Pump Intake
- ESP Pump
- Discharge Pressure Sub
- Discharge Head
- Pump Sub
- Telescopic Swivel
- Bypass Nipple & Blanking Plug
- Y-Tool
- Top Nipple
- Handling Sub
- Production Tubing Connection
The Pump Support Sub is an optional component of the Y-tool bypass system. It is primarily used when running dual ESP’s or when tailpipe is to be run below the ESP and located into a Polished Bore Receptacle (PBR).
The purpose of the Pump Support Sub is to share any compressive loading between the bypass tubing and the ESP during installation and operation (set down weight), and tensile loading to the bypass tubing upon retrieval of the system.
The pump support also allows the system to be built with the bypass tubing taking all the string weight. The ESP is simply supported by the pump support block ensuring no tensile loading of the string weight is supported by the ESP flangebolts.
An example of when a pump support would be used is as follows. The Y-tool system comprises of 2-7/8” 6.4# L80 F2J tubing with a tensile strength of 67,000lbs and a compressive strength of 28,000lbs.
The tailpipe below the ESP has a perforated joint and a seal assembly with a no-go locator which stabs into a seal bore packer. A set down (slack off) weight is applied to engage the seal assembly seals and land the seal assembly.
Prior to the job, a tubing stress analysis is carried out and shows when the well is flowing the tubing string thermally expands. Due to the restriction of the No-Go locator, the tubing is not free to expand and the compressive force on the tubing string is shown to exceed the compressive strength of the bypass tubing.
The ESP compressive strength is greater than the expected load so a pump support is selected. The ESP weight should always be considered when using a pump support in relation to the tensile capacity of the system for installation.
For instance, 2-7/8” 6.4# L80 F2J tubing has a tensile strength of 67,000lbs without a safety factor. If the ESP weight is 12,000lbs then the available tensile capacity is 67,000lbs minus 12,000lbs which is 55,000lbs without a safety factor.
Another advantage of the pump support is that it acts as a tubing centre shift adapter between the bypass tubing and the tailpipe. The tailpipe below the pump support block is tangentially in line with the bypass tubing shifting the tailpipe towards the well centre. This is a particular advantage when you have a liner.
Without the pump support, the tailpipe can be more difficult to get into the liner, and bending of the tubing can create a forced dog leg that could potentially prevent a long production logging tool string from passing through the dog leg.
The created dog leg severity is increased the closer the ESP is to the liner top. Having a larger tailpipe connection than bypass connection on the pump support eliminates the problems that potentially can be encountered.
