Downhole Joint Seal and Weld Structure for Corrosion and Pressure

Solution Overview

Problem

Existing downhole tools face challenges in achieving both high yield strength and NACE/ISO compliance, particularly in corrosive environments and under extreme pressures and temperatures.

Innovation Solution

The development of tubular joints that incorporate a crack compliant seal and a high yield strength weld at the joint, with the crack compliant seal having a compliant seal hardness value less than or equal to the member hardness values and the high yield strength weld having a yield strength of at least 50 ksi.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high yield strength weld is used at the joint, then the joint can withstand greater collapse and burst pressures, but the joint may lack corrosion resistance and NACE/ISO compliance in harsh environments

Engineering Contradiction:

Improveyield strengthVSAvoidcorrosion resistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The joint is segmented into two distinct components: a high yield strength weld providing mechanical strength and a separate crack compliant seal providing corrosion resistance. This segmentation allows each component to optimize its specific function without compromising the other, resolving the contradiction between strength and reliability in corrosive environments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The joint employs a composite structure combining dissimilar materials: a high strength weld material for mechanical support and a crack compliant seal material for corrosion protection. This composite approach enables the joint to simultaneously achieve high yield strength (at least 50 ksi) and NACE/ISO compliance by leveraging the complementary properties of different materials.

Inventive Principle:

Principle #40Composite materials

2Reliability

If crack compliant seal is used at the joint, then the joint maintains corrosion resistance, but the joint may not provide sufficient mechanical strength to withstand extreme pressures

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidyield strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The joint is segmented into two distinct components: a high yield strength weld providing mechanical strength and a separate crack compliant seal providing corrosion resistance. This segmentation allows each component to optimize its specific function without compromising the other, resolving the contradiction between strength and reliability in corrosive environments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The joint employs a composite structure combining dissimilar materials: a high strength weld material for mechanical support and a crack compliant seal material for corrosion protection. This composite approach enables the joint to simultaneously achieve high yield strength (at least 50 ksi) and NACE/ISO compliance by leveraging the complementary properties of different materials.

Inventive Principle:

Principle #40Composite materials

3Strength

If geometric mechanical joining methods are used, then the joint provides mechanical connection, but the joint cannot achieve simultaneous anchoring and sealing without additional sealing elements

Engineering Contradiction:

Improvemechanical connectionVSAvoidnumber of components

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The invention merges the mechanical connection function and sealing function into a single integrated joint structure. The high yield strength weld provides both the mechanical anchoring and the sealing barrier, eliminating the need for separate sealing elements such as elastomeric inserts or plastic seals. This consolidation reduces device complexity while maintaining both mechanical strength and sealing capability.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12326203B2Downhole tool with crack compliant seal and mechanical strengthening feature at a joint thereof

Publication Date: 2025.06.10 HALLIBURTON ENERGY SERVICES INC

AI summary

Provided is a downhole tool, a well system and a method. The downhole tool, in one aspect, includes a first member, the first member having a first member hardness value (HV1), and a second member, the second member having a second member hardness value (HV2), the first and second members positioned proximate one another forming an overlapping space therebetween. The downhole tool according to this aspect, further includes a mechanical strengthening feature located between the first member and the second member, the mechanical strengthening feature configured to increase an engineering rating of the overlapping space, and a crack compliant seal positioned at the overlapping space, the crack compliant seal having a compliant seal hardness value (HVcs) less than or equal to one or more of the (HV1) or the (HV2).