Bottom Hole Assembly Mechanical Depth Correlation
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Solution Overview
Problem
Current methods for depth correlation and wellbore circulation during abrasive jetting and fracturing operations with coiled tubing face challenges due to imprecise depth control and the need for multiple trips to adjust sand plugs, which can lead to inefficiencies and risks of tool sticking.
Innovation Solution
A bottom hole assembly (BHA) equipped with a mechanical casing collar locator and a circulation valve allows for precise depth determination and fluid circulation, enabling single-trip operations by engaging with casing collars and controlling fluid flowpaths to perform wellbore operations accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If coiled tubing is used for abrasive jetting and fracturing operations, then intervention speed is improved, but depth control precision deteriorates due to tubing stretching and shrinking
Solution Approach 1:
A mechanical depth correlation device is introduced as an intermediary between the coiled tubing system and the casing collars. This device mechanically engages with the casing collars to provide accurate depth reference points, mediating the depth measurement function and compensating for the tubing's elastic deformation. The mechanical engagement transfers the depth reference from the flexible tubing to the rigid casing structure, resolving the depth control issue while maintaining the speed benefits of coiled tubing.
Solution Approach 2:
The patent replaces electronic or pump-based depth correlation methods with a purely mechanical depth correlation system. The mechanical depth correlation device uses physical engagement with casing collars to determine depth, substituting more complex electronic sensing or pressure-based methods. This mechanical approach provides reliable depth reference despite tubing deformation, enabling accurate depth control during high-speed coiled tubing operations.
2Reliability
If sand plugs are used to separate fracturing stages, then formation isolation is improved, but operational complexity increases due to imprecise plug placement requiring multiple trips
Solution Approach 1:
The mechanical depth correlation device provides real-time feedback on the BHA's depth position by mechanically engaging with known casing collar locations. This feedback enables the operator to monitor and control sand plug placement depth with high precision, ensuring accurate formation isolation. The depth feedback eliminates the need for trial-and-error placement and subsequent remedial operations, reducing operational complexity while maintaining reliable formation isolation.
3Measurement precision
If mechanical depth correlation devices are used during treatment, then depth measurement is improved, but risk of tool sticking increases due to close clearance requirements
Solution Approach 1:
The mechanical depth correlation device is designed and configured before deployment to ensure proper engagement geometry with the casing collars. The engagement features are pre-formed with appropriate clearances and tolerances to allow smooth mechanical interaction without risk of sticking. This preliminary design consideration eliminates the need for tight clearances during operation, maintaining both accurate depth measurement and reliable tool retrieval.
Data Source
AI summary
An embodiment of a method of performing a wellbore operation in an oilfield comprises providing a bottom hole assembly on a conveyance, deploying the bottom hole assembly into the wellbore with the conveyance, determining the depth location of the bottomhole assembly in the wellbore utilizing a mechanical device, moving the bottom hole assembly to a desired location based on the determined depth, circulating a fluid from the oilfield to the bottomhole assembly, and performing at least one wellbore operation while the bottomhole assembly is deployed at the desired location.