Downhole Swellable Sealant Tool for Drilling Mud Loss
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Solution Overview
Problem
During deep well drilling, existing methods face challenges in timely detection and remediation of mud loss due to the difficulty in circulating and controlling the setting time of remedial fluids like cement or swelling materials, which are often cumbersome and hard to manage at great depths.
Innovation Solution
A downhole drilling tool that detects mud loss and automatically releases a swellable sealant agent from a tank near the drill bit, which mixes with water to form a gel-like substance that blocks fractures, effectively stopping mud loss without significant net volume increase, even under varying pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If remedial fluid such as cement or swelling material is introduced from the surface, then the mud loss can be remedied, but it is difficult to control the setting and curing time and the process is cumbersome
Solution Approach 1:
The swellable agent is pre-loaded in a tank at the bottom of the drill string, ready for immediate deployment when mud loss is detected. This eliminates the need to pump large volumes of remedial fluid from the surface and allows precise control of when the remediation action occurs.
Solution Approach 2:
The swellable agent is extracted from the drill string system and placed in a separate tank, allowing it to be deployed independently near the drill bit. This separation enables precise local application of the remedial agent directly at the mud loss site.
2Reliability
If remedial fluid is pumped from surface to stop mud loss, then the loss can be stopped, but the amount of pumped fluid is large (tens of cubic metres) and the process is time-consuming
Solution Approach 1:
The swellable agent is extracted from the bulk drill string system and contained in a localized tank near the drill bit. This allows the remedial agent to be applied locally at the mud loss site rather than requiring large volumes to be pumped through the entire wellbore from the surface.
Solution Approach 2:
The swellable agent is applied locally at the mud loss site through the tank outlet positioned near the drill bit. This localized application ensures the remedial agent is delivered precisely where needed, minimizing the total quantity required compared to surface pumping methods.
3Reliability
If remedial fluid is pumped from surface, then mud loss can be addressed, but the time to circulate and set the remedial agent is excessive at several kilometers depth
Solution Approach 1:
The swellable agent is pre-positioned in the tank at the bottom of the drill string, ready for immediate deployment. When mud loss is detected, the agent can be released instantly and begins working at the mud loss site without the time delay of circulating from the surface through kilometers of wellbore.
Solution Approach 2:
The remediation process is extracted from the surface operation and moved to the bottomhole assembly. This eliminates the circulation time through the entire wellbore and allows the swellable agent to be applied and begin setting at the mud loss site immediately.
4Productivity
If a tank with swellable agent is deployed downhole, then quick response to mud loss is achieved, but the device complexity increases
Solution Approach 1:
The tank assembly is integrated into the bottom of the drill string, combining the functions of drill string termination and remedial agent containment. The diverter sub serves multiple purposes including flow direction and tank support, reducing the need for separate components.
Solution Approach 2:
The tank, diverter sub, and drill string connection are merged into a single integrated assembly. This consolidation reduces the number of separate components and interfaces, simplifying the overall device while maintaining the quick response capability for mud loss remediation.
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 tool rapidly addresses mud loss by deploying the swellable agent close to the loss site, ensuring quick sealing and maintaining drilling efficiency without increasing the overall volume, thus overcoming the limitations of traditional remediation methods.
Implementation Method 1
the reacting fluid will continue to react with water and expand to form a gel-like substance which blocks the cracks and fissures
Implementation Method 2
release a swellable sealant agent from a downhole tank to near the drilling bit and let it mix with water
Data Source
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AI summary
The invention is a mud loss treatment drilling tool (1) comprising - said tool (1) having an upper tooljoint (101U) to a lower end of an above drill pipe string (0), - one or more tank (10) with a through channel (101) for a drilling fluid flow, - a lower tooljoint (101L) connected to a BHA assembly (2, 3) at least comprising a drill bit (3); - said tank (10) arranged for holding a swellable sealant agent (5); - said swellable sealant agent (5) arranged for mixing with water (w) to swell; - said tank (10) provided with an outlet (120) to said through channel (101) for said swellable sealant agent (5), so as for, when an undesired mud loss is detected, for flushing all or part of said swellable sealant agent (5) into said through channel (101), so as for a mixture (5, w) of said swellable agent (5) and said water (w) to start reacting to swell during the time it takes the mixture (5, w) to reach a fracture (f) extending from a well under drilling by said BHA, so as for continuing to swell and block said fracture (f) to stop said undesired mud loss.