LWD Wet Connection Vibration Isolation
Solution Overview
Problem
Existing logging while drilling (LWD) and measurement while drilling (MWD) tools face challenges with electrical connections due to downhole vibrations and shock, requiring precise length matching and complex spring-loaded designs that are prone to failure.
Innovation Solution
A spring-loaded cable connects upper and lower assemblies with pressure bulkheads, encapsulated by a pressure housing that provides multiple layers of protection, including double sealing and rotational freedom, to maintain reliable electrical connections despite vibrations and shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spring loaded connectors are used to compensate for vibration and shock, then connection reliability is improved, but device complexity increases
Solution Approach 1:
The connector is divided into separate functional components: spring loaded contacts for electrical connection, pressure bulkheads for pressure isolation, and a pressure housing for encapsulation. This segmentation allows each component to perform its specific function independently, maintaining connection reliability while managing complexity through modular design
Solution Approach 2:
The pressure housing encapsulates the spring loaded cable and pressure bulkheads, creating a nested structure where the pressure housing protects the internal components from downhole pressures and vibrations. This nesting approach provides multiple layers of protection while organizing complexity into a compact, hierarchical arrangement
2Manufacturing precision
If precise length matching of collars is required, then connection precision is improved, but ease of operation deteriorates
Solution Approach 1:
The design changes the critical parameter from collar length matching to collar OD (outer diameter) matching. By requiring only that the collar ODs match within standard tolerances rather than precise length matching, the system maintains connection precision while significantly improving ease of operation and field assembly
3Reliability
If pressure protection is added to protect electrical contacts, then reliability is improved, but device complexity increases
Solution Approach 1:
The pressure bulkheads act as intermediary components between the electrical contacts and the downhole pressure environment. These bulkheads isolate the electrical contacts from direct pressure exposure while allowing the pressure housing to provide structural protection, thereby protecting reliability without requiring the entire connector to be overly complex
Solution Approach 2:
The pressure housing serves as a protective shell that encapsulates the spring loaded cable and pressure bulkheads. This housing provides pressure protection and vibration isolation while maintaining a relatively simple cylindrical structure that doesn't significantly increase overall device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a simple, reliable assembly with higher collar length deviation tolerance, isolating electrical contacts from shock and vibration, and achieving signal transfer quality comparable to wireline connections.
Implementation Method 1
The longitudinal vibrations and shock accelerations can reach hundreds g with spikes above 1000 g. The spring loaded cable operably connecting an upper assembly and a lower assembly... isolating electrical contacts from shock and vibration
Data Source
AI summary
Electrical wet connection (EWC) with multiple power and communication lines for connecting Logging While Drilling tools (LWD) and/or Measurement While Drilling tools (MWD) is described. The contacts between the modules may be made by, for example, using pressure bulkheads to ensure protection of the tools if the pressure protection is reduced or lost. The contacts may be locked together in a convenient manner to eliminate downhole vibrations and/or shocks. The may make the signal transmission quality approaching, as good as, or even better than wireline tools. The connection may be sealed from the well muds under high pressure and this protection may be enhanced such as by doubling or even tripling for extreme reliability in difficult environments. The designs described herein may advantageously allow for a large amount in collar lengths to be compensated and/or provide two degrees of freedom-rotational and/or may be longitudinal for ready connection on the well site.