Expandable Packer for Emergency Underwater Well Killing
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Solution Overview
Problem
Current methods for well killing, such as gradual squeezing of viscoelastic materials and inflatable cementer units, are ineffective for emergency killing of underwater flowing wells due to inability to introduce kill fluids against fluid flow and secure at target depths, especially when conventional preventers fail.
Innovation Solution
A device comprising a pipe with a tank containing cementing composition and an expandable element, where the tank is fixed to the pipe, and a piston separates the internal volume into two portions, allowing the cementing composition to be pumped into the expandable element, which is made of flexible material, enabling it to fill the well section and withstand fluid flow pressure, with a system for maintaining pressure until the composition hardens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional inflatable cementer units are used to isolate well sections, then temporary isolation can be achieved, but the device cannot introduce kill fluid against fluid flow or secure at target depth in flowing wells
Solution Approach 1:
The device places a packer in the well ahead of time, before the well flow becomes unmanageable. The packer is positioned and secured in advance, creating a sealed zone that can later receive kill fluid even when the well is flowing uncontrollably. This preliminary positioning allows the system to handle flowing wells that conventional methods cannot address.
Solution Approach 2:
The packer acts as an intermediary element between the kill fluid injection system and the wellbore. It creates an isolated zone that mediates the introduction of kill fluid against the flowing well fluids, enabling pressure control and fluid diversion without direct confrontation with the full flow force.
2Reliability
If gradual squeezing of viscoelastic material and cement slurry is performed to kill wells, then killing can be achieved under benign conditions, but the method cannot be used for underwater flowing wells when preventer fails
Solution Approach 1:
The packer is deployed in advance into the wellbore and positioned at the desired depth before the emergency killing operation begins. This preliminary placement creates a sealed isolation zone that allows subsequent injection of killing fluids even in emergency underwater conditions where conventional preventers have failed.
Solution Approach 2:
The packer utilizes flexible elements that can conform to the wellbore geometry and create effective seals under varying pressure conditions. These flexible components allow the device to adapt to the wellbore shape and maintain isolation effectiveness in the challenging environment of underwater flowing wells.
3Reliability
If expandable tubular elements are used for borehole isolation, then temporary isolation is possible, but expansion causes considerable increase in expulsive force preventing fixation at target depth
Solution Approach 1:
The packer is lowered and positioned in the wellbore before any expansion or cementing operations occur. This preliminary positioning allows the system to establish the isolation zone first, then apply expansion forces locally without generating significant expulsive forces that would prevent depth fixation.
Solution Approach 2:
The isolation function is divided into separate components: the packer for mechanical isolation and positioning, and the cementing/squeezing operation for permanent sealing. This segmentation allows each component to perform its function optimally without interfering with the other, avoiding the expulsive force problem of simultaneous expansion and cementing.
4Reliability
If kill fluid is introduced into flowing well at necessary depth, then well killing can be achieved, but the fluid flow generates considerable expulsive force preventing proper introduction and fixation
Solution Approach 1:
The packer is positioned in the wellbore before kill fluid introduction begins. This creates a sealed zone that confines the kill fluid at the target depth, allowing injection against the flowing well fluids without the fluid being expelled by the wellbore flow. The preliminary sealing enables controlled kill fluid placement even in flowing conditions.
Solution Approach 2:
The packer serves as an intermediary that creates an isolated chamber between the kill fluid injection point and the flowing wellbore environment. This intermediary sealed zone allows kill fluid to be introduced and held in place against the expulsive forces of the flowing well, enabling effective well killing operations.
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
Enables emergency killing of underwater flowing wells by overcoming fluid flow pressure and ensuring the cementing composition remains in place, reducing material and operational costs while providing reliable well isolation.
Implementation Method 1
a piston (6) separating the internal volume of the tank (3) into two portions, the first volume (31) being filled with the cementing composition (4) and connected to the pipe (1) for injecting the cementing composition into the expandable element (2)
Implementation Method 2
an expandable element (2), made of a flexible material, with a possibility of filling its internal volume with the cementing composition (4) from the tank (3)
Implementation Method 3
The viscoelastic material in the well is cured until it gels and acquires its structural strength
Data Source
AI summary
The invention relates to oil-and-gas industry and can be used in emergency killing of wells. The method of emergency killing of a well of underwater head position comprises a cementing composition squeezing, wherein depth of the well section to be cemented is defined basing on the well condition and pressure in it, an injector, fixed on the tank with cementing composition and placed inside a bag made of some flexible material, is bottomed and inserted into the wellhead, the bag being filled with cementing composition which is squeezed into the bag through the injector from the tank, and providing for a firm contact of outer surface of the bag with inner surface of the well, the injector being kept at a target depth by means of the weight of the whole structure filled with the cementing composition, pressure in the bag being maintained till the cementing composition hardening.