ESP Cable Arrangement for Narrow Annular Gap Installation
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Solution Overview
Problem
Current methods for routing power and signal cables to Electrical Submersible Pumps (ESPs) face challenges such as complex and costly installation, reliance on downhole valves, and limitations in using both internal and external cabling options, particularly in vertical Christmas trees and existing wells, which restricts efficient first-time installation and replacement of ESP units.
Innovation Solution
A novel cable arrangement featuring an upper suspension element, a lower connector, and a docking station adapted for attachment to the production tubing, with a cable design that includes a ring-shaped configuration with a central void and distributed lines, allowing for a larger cross-section of power and signal lines, and incorporating flexible sleeves and spring elements to fit within the narrow gap between the pump unit and production tubing, enabling easier installation and reduced risk of damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If internal cabling method is used with coiled tubing, then the pump unit can be suspended and powered, but the installation becomes complex and costly, and the system requires downhole valves for closing the well
Solution Approach 1:
The patent extracts the cable routing from the production tubing interior to the exterior annulus space. The cable assembly is routed through the wellhead and Christmas tree without penetrating the production tubing, eliminating the need for complex internal cabling systems and downhole valve dependencies.
Solution Approach 2:
The cable assembly serves multiple functions: it provides electrical power, signals, and hydraulic fluid delivery through an integrated multi-conductor design. The single cable assembly replaces multiple separate systems, simplifying installation and reducing the need for specialized completion modifications.
2Adaptability or versatility
If external cabling method is used with penetration through production tubing, then the cable can be routed outside the tubing, but the completion system requires special features and the Christmas tree must be replaced
Solution Approach 1:
The cable assembly integrates multiple functions (power, signal, hydraulic) into a single multi-conductor cable that can be routed through standard wellhead and Christmas tree penetrations, making the system compatible with existing completions without requiring specialized modifications or tree replacements.
Solution Approach 2:
The cable assembly is divided into modular sections with distinct functional segments (power conductors, signal conductors, hydraulic channels), allowing flexible configuration and routing through standard infrastructure while maintaining adaptability to different well configurations.
3Productivity
If conventional cable design is used, then the cable structure is simple, but the cable cannot accommodate larger cross-section of power and signal lines needed for higher pump capacity
Solution Approach 1:
The cable assembly employs a nested multi-layer structure where multiple conductors and hydraulic channels are concentrically arranged around a central axis. Power conductors, signal conductors, and hydraulic flow channels are nested within each other, maximizing the utilization of the available annular space between the pump and production tubing while accommodating larger cross-sections for higher power and signal capacity.
Solution Approach 2:
The cable transitions from a traditional linear arrangement to a three-dimensional annular configuration that utilizes the radial space between the pump outer diameter and production tubing inner diameter. This dimensional optimization allows larger cable cross-sections to fit within the constrained annular gap, supporting higher pump capacities without increasing the pump diameter.
4Area of stationary object
If the cable is routed in the narrow gap between pump unit and production tubing, then space is utilized efficiently, but the cable is at risk of damage from pump rotation and well operations
Solution Approach 1:
The cable assembly utilizes composite construction with multiple protective layers including corrosion-resistant outer jackets, mechanically strong aramid fiber reinforcement, and electrically conductive shielding. The hydraulic channels are protected by corrosion-resistant linings, and the overall assembly is designed to withstand the harsh downhole environment, pump rotation forces, and mechanical stresses from well operations.
Solution Approach 2:
The cable assembly incorporates pre-installed protective features including corrosion-resistant coatings, mechanical reinforcement layers, and flexible joints that accommodate movement and rotation. The hydraulic channels are designed with expansion joints and flexible connections that prevent damage during pump installation, rotation, and operation, cushioning against mechanical stresses before they can cause failure.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A cable arrangement for feeding power and signals to downhole equipment, such as an electrically submersible pump (6), within an oil or gas well, comprising an upper suspension element (15), a lower connector (22), a docking station (11') for the downhole equipment coupled to said connector (22), and a cable (8a), comprising lines for power and signal. The cable extends between, and is coupled to, the upper suspension element (15) and the lower connector (22). The docking station (11') is adapted for attachment to the inner surface of a production tubing (5), that a narrow gap is formed between the production tubing (5) and the downhole equipment (6). The cable (8) is shaped to fit inside the gap by having a first dimension in the radial direction of the gap, which is smaller than the gap and a second dimension in the tangential direction of the gap, which is substantially larger than the first dimension.