Workover Tool String Tubing Cutting and Penetration

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Solution Overview

Problem

Current methods for optimizing hydrocarbon production in depleting wells are expensive and require heavy equipment, posing a need for a less costly yet safe solution to increase hydrocarbon recovery without compromising well safety.

Innovation Solution

A workover tool string with a tubing cutting unit and penetration unit allows for simultaneous cutting and hole creation in the production tubing, enabling fluid circulation and safe replacement of tubing sections, reducing drill rig time and costs while maintaining well control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If heavy equipment such as drill rig is used to insert gas lift valves or velocity string, then well optimization can be achieved, but the cost and equipment complexity increase significantly

Engineering Contradiction:
Improvewell optimization effectivenessVSAvoidequipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The workover tool string is divided into separate functional modules: a penetration unit for creating holes in the production tubing, a tubing cutting unit for cutting the tubing, and a deployment tool for setting plugs. These modular units can be selectively used based on operational needs, reducing the complexity and cost compared to using heavy drill rig equipment for all operations.

Inventive Principle:
Principle #1Segmentation

2Productivity

If drill rig is used for tubing replacement operation, then complete replacement can be performed, but drill rig time and cost increase substantially

Engineering Contradiction:
Improvetubing replacement capabilityVSAvoiddrill rig time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The invention extracts the essential functions needed for tubing replacement from the heavy drill rig system and implements them in a lighter, more efficient workover tool string. The penetration unit creates holes for fluid circulation, the cutting unit separates tubing sections, and the deployment tool sets plugs - all without requiring drill rig equipment, thereby reducing drill rig time and costs.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If production tubing is cut and holes are created separately, then well control can be maintained, but operation time and complexity increase

Engineering Contradiction:
Improvewell controlVSAvoidoperation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention combines the penetration unit and tubing cutting unit into a single integrated workover tool string. The penetration unit creates holes in the production tubing for fluid circulation to maintain well control, while the cutting unit simultaneously or sequentially cuts the tubing. This integration allows both operations to be performed in one deployment, improving efficiency without compromising well control.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3784873B1Workover tool string
Publication Date: 2024.07.24 WELLTEC AS
  • EP3784873B1 patent drawingFigure 1
  • EP3784873B1 patent drawingFigure 2
  • EP3784873B1 patent drawingFigure 3

AI summary

The present invention relates to a workover tool string (1) for cutting into a production tubing (2) of a well completion (100) having a top (3), the well completion comprising a casing (4) into which the production tubing is arranged and a production packer (5) arranged between the casing and the production tubing defining an annulus (6) above the production packer, the workover tool string comprising: a longitudinal axis (7), a first tool string end (8) and a second tool string end (9), the first tool string end being arranged closer to the top when submerged into the well completion, a tubing cutting unit (10) comprising a body (11) and a cutting edge (12) configured to be rotated around the longitudinal axis while being projected in relation to the body for cutting into a wall (14) of the production tubing from within in order to separate a first part (15) of the production tubing closest to the top from a second part (16) of the production tubing, wherein the workover tool string further comprises a tubing penetration unit (20) comprising a projectable penetration element (21) configured to create at least one hole (22) in the wall of the first part for creating a fluid communication between the annulus (6) and an inside (23) of the production tubing in order to obtain well control by circulating fluid there between, the penetration unit being arranged closer to the first tool string end than the tubing cutting unit. The present invention further relates to a downhole system and to a repairing method.