Wellhead Workover Spool Replacement Method

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Solution Overview

Problem

Wellhead workover operations in oil and gas drilling are time-consuming and costly due to the need to change the height of the wellhead, which disrupts the connection to production lines, requiring extensive reconstruction.

Innovation Solution

A method involving a wellhead configuration with a first casing spool, an extended tubing spool, and a production tree with a wing valve, where the extended tubing spool is decoupled and replaced with a combination of a replacement tubing spool and an additional casing spool of equal length, maintaining consistent vertical and radial alignment with the wing valve and production line connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the height of the wellhead is changed by adding a new casing spool, then the wellhead configuration is improved, but the production tree connection is disrupted requiring reconstruction

Engineering Contradiction:

Improvewellhead configurationVSAvoidproduction tree reconstruction

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The extended tubing spool is divided into two separate spools (first tubing spool and second tubing spool) that can be independently installed and removed. This segmentation allows the wellhead configuration to be modified without affecting the production tree, as each spool can be replaced individually while maintaining the overall system connection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The extended tubing spool is extracted as a separate, removable component from the wellhead assembly. By taking out the extended tubing spool as an independent element, the patent enables wellhead configuration changes without disrupting the production tree connection, as the extended functionality is achieved through the removable spool rather than permanent structural modification.

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If the wellhead height is changed, then the wellhead configuration is improved, but the workover time increases to 30 days or more

Engineering Contradiction:

Improvewellhead configurationVSAvoidworkover time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The tubing spool system is segmented into modular units (first tubing spool and second tubing spool) that can be quickly swapped. This segmentation reduces workover time by allowing rapid replacement of individual spools without requiring extensive disassembly or reconstruction of the entire wellhead assembly, cutting the 30-day workover period significantly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The extended tubing spool is pre-installed as a removable component during the initial wellhead assembly. This preliminary action enables future configuration changes to be made by simply replacing the pre-positioned spool rather than performing complex reconstruction operations, thereby reducing subsequent workover time.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the extended tubing spool is replaced with replacement tubing spool and additional casing spool, then the wellhead configuration is improved, but the vertical alignment must be maintained

Engineering Contradiction:

Improvewellhead configurationVSAvoidvertical alignment

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The replacement assembly is segmented into a replacement tubing spool and an additional casing spool, each with standardized connection interfaces. This segmentation allows for modular installation while maintaining precise vertical alignment through standardized threading and coupling mechanisms designed to ensure proper positioning.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The additional casing spool serves multiple functions: it provides the necessary length extension and acts as a precision alignment component with standardized connections. This universal component design ensures that vertical alignment is maintained during replacement operations while allowing configuration flexibility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12258832B2Methods for wellhead workover

Publication Date: 2025.03.25 SAUDI ARABIAN OIL CO

AI summary

The method includes providing a wellhead comprising a first casing spool and an extended tubing spool disposed above the first casing spool, and a production tree comprising a wing valve disposed above the extended tubing spool. The method further includes decoupling the extended tubing spool from the wellhead, coupling a replacement tubing spool and an additional casing spool below the replacement tubing spool to the wellhead replacing the extended tubing spool. A combined length of the replacement tubing spool and the additional casing spool is the same as the length of the extended tubing spool. The method further includes maintaining a consistent vertical length between the first casing spool and the wing valve while replacing the extended tubing spool with the replacement tubing spool and the additional casing spool.