Drill String Scraper Deployment Mechanism for Single-Trip Operations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current drilling and casing scraping methods require multiple trips, leading to increased rig time and costs, as existing systems are not suited for simultaneous drilling and scraping, especially when dealing with undesirable deposits on existing casing.
Innovation Solution
A drilling assembly with integrated retention and release system for scrapers and a ported sub that allows circulation during scraping, enabling the scrapers to be deployed and circulation ports to be opened in a single trip, allowing for high circulation rates and efficient debris removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate trips are used for drilling and casing scraping, then scraping equipment can be deployed, but rig time and costs increase
Solution Approach 1:
The patent combines drilling and casing scraping operations into a single trip by integrating scrapers onto the drill string. The scrapers are positioned to contact the casing during the drilling operation, allowing both functions to be performed simultaneously without requiring separate trips, thereby reducing rig time while maintaining effective scraping capability
Solution Approach 2:
The drill string is designed with multi-functionality, serving both as the drilling tool and as the carrier for casing scraping equipment. The scrapers are attached to the drill string in such a way that the same assembly performs both drilling and scraping functions, eliminating the need for separate specialized equipment trips
2Productivity
If circulation is enabled during scraping, then debris removal efficiency increases, but system complexity increases
Solution Approach 1:
The circulation system is pre-configured and integrated into the drill string assembly before entering the wellbore. The circulation ports and fluid pathways are built into the scraper assembly and drill string, allowing circulation to be activated immediately when needed during the scraping operation without requiring additional complex deployment mechanisms
Solution Approach 2:
The patent utilizes hydraulic circulation through the drill string to remove debris during scraping. Fluid is pumped down through the drill string and annulus, creating a circulation pattern that carries cuttings and debris to the surface. This hydraulic system is integrated into the existing drilling circulation infrastructure, avoiding the need for separate pneumatic or mechanical debris removal systems
Data Source
AI summary
A drilling assembly is tripped in a cased hole to make more open hole. The assembly features retracted scrapers and a closed circulation sub so that the drilling can commence with string pressure delivered to bit nozzles due to the circulation sub being in a closed position. When drilling is done and the bit is to be removed, an object lands on a seat on a sleeve that acts as a piston to break scraper retainers for casing scraping deployment and to open the circulation port. A bypass opens around the seated ball when the sleeve shifts to allow flow around the seated ball for circulation while scraping. Drilling and casing scraping are accomplished in a single trip.