Underbalanced Drilling System with Continuous Circulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional drilling methods often damage hydrocarbon reservoirs with natural fractures due to drilling fluid entering the fractures, and they require acid cleaning and face challenges in maintaining a precise balance of fluid circulation during wellbore drilling, leading to potential well kicks and collapses.
Innovation Solution
An underbalanced drilling system utilizing a drill string with multiple drill collars and a hydraulic workover unit that maintains a continuous circulation of drilling fluid, preventing fluid entry into natural fractures, and uses real-time telemetry to manage wellbore parameters, allowing for precise control of fluid density and pressure to avoid damage and maintain well integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional drilling methods are used, then drilling fluid enters natural fractures, but this damages hydrocarbon reservoirs
Solution Approach 1:
The patent changes the pressure parameter by maintaining underbalanced drilling conditions where the wellbore pressure is kept lower than the formation pressure. This prevents drilling fluid from entering natural fractures while still allowing effective drilling operations, thereby protecting reservoir integrity without sacrificing drilling effectiveness
Solution Approach 2:
The system employs real-time monitoring and control of wellbore pressure and fluid circulation parameters. Telemetry systems provide continuous feedback on drilling conditions, allowing operators to adjust parameters to maintain the underbalanced state and prevent fracture entry, thus resolving the contradiction between drilling fluid circulation and reservoir protection
2Ease of operation
If drilling fluid circulation is interrupted to couple new drill collars, then drill collar replacement is possible, but wellbore density changes and may cause kicks or collapses
Solution Approach 1:
The patent implements a continuous circulation system that maintains drilling fluid flow throughout the wellbore even during drill collar replacement operations. The system uses a workover unit with hydraulic control to lower new collars while fluid circulation continues uninterrupted, preventing wellbore pressure changes that could cause kicks or collapses, thus enabling both easy operation and maintained stability
Solution Approach 2:
The workover unit acts as an intermediary device that facilitates drill collar replacement without interrupting fluid circulation. It provides a mechanical interface between the surface equipment and the drill string, allowing collar changes while the continuous fluid flow maintains wellbore stability, resolving the contradiction between operational ease and wellbore reliability
3Reliability
If underbalanced drilling is used to prevent fluid entry into fractures, then reservoir damage is avoided, but precise balance of fluid circulation must be maintained
Solution Approach 1:
The workover unit is designed as a multi-functional device that combines drilling, well control, and fluid circulation management capabilities. It can perform multiple operations including drill collar replacement, pressure control, and continuous fluid circulation, thereby managing the complexity of underbalanced drilling through a single versatile platform rather than multiple separate systems
Solution Approach 2:
The system incorporates automated telemetry and control mechanisms that continuously monitor wellbore conditions and automatically adjust circulation parameters to maintain the underbalanced state. This self-regulating capability reduces the operational complexity of maintaining precise fluid balance while ensuring continuous reservoir protection
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 system effectively drills underbalanced wells without damaging natural fractures, prevents fluid entry into fractures, maintains well integrity, and ensures continuous fluid circulation during drill collar changes, reducing the risk of well kicks and collapses.
Implementation Method 1
a pump is operable to pump drilling fluid into a channel of the drill string through an upper supply conduit coupled with an upper end of a top drill collar of the drill string
Implementation Method 2
the continuous circulation component operable to provide continuous circulation of the drilling fluid while a new drill collar is coupled to the drill string to maintain a wellbore density at a predetermined density
Implementation Method 3
a telemetry component operable to transmit data in real-time between a bottomhole assembly and a controller at the surface
Data Source
AI summary
An underbalanced drilling system is provided. A bottomhole assembly includes a drill bit drilling a wellbore in a formation underbalanced. The bottomhole assembly includes a telemetry sub. A telemetry component transmits signals in real-time between the telemetry sub of the bottomhole assembly and a controller on the surface. A drill string is coupled with the bottomhole assembly, and the drill string includes a plurality of drill collars. The drill collars form a channel through which drilling fluid flows from the surface to the bottomhole assembly. The drill string is inserted into the wellbore by a hydraulic work over unit. A continuous circulation component provides continuous circulation of the drilling fluid while a new drill collar is coupled to the drill string. The continuous circulation component substantially maintains a wellbore density at a predetermined density.