Flow Diverter Choke System for Drilling Cuttings Transport
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Solution Overview
Problem
During drilling operations, excessive drill cuttings in the borehole annulus increase friction on the drill string, risking it to get stuck, and existing mud flow diversion methods either fail to clear cuttings effectively or risk fracturing subsurface formations due to high mud velocity and pressure.
Innovation Solution
A flow diverter system that reduces the pressure and velocity of mud diverted to the borehole annulus by using a series of chokes and an actuation system to control fluid flow, dissipating hydraulic energy and ensuring safe diversion of mud flow, thereby reducing the risk of formation damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mud flow is diverted from the drill string to the annulus to clear cuttings, then cuttings transport is improved, but the risk of fracturing subsurface formations increases due to high mud velocity
Solution Approach 1:
A flow diverter device is introduced as an intermediary component between the drill string and the annulus. This device includes a body with a bore and a diverter element that can be positioned to divert mud flow from the drill string interior to the annulus. The flow diverter acts as a controlled intermediary that manages the diversion process, allowing cuttings clearance while controlling the release of high-velocity mud to prevent formation fracturing.
Solution Approach 2:
The system changes the flow parameters by controlling the diversion of mud from high-velocity internal flow to controlled annular flow. By adjusting the position of the diverter element and controlling the timing and rate of diversion, the system modifies flow velocity and pressure parameters to achieve effective cuttings transport while maintaining safe operating conditions for the formation.
2Productivity
If mud flow rate is increased to ensure proper cuttings transport, then cuttings clearing is improved, but the risk of BHA damage or destruction increases
Solution Approach 1:
The mud flow is segmented into different pathways: flow through the drill string, flow diverted to the annulus, and flow continuing to the BHA. The flow diverter creates separate flow channels, allowing independent control of flow rates to different destinations. This segmentation enables sufficient flow for cuttings clearance while protecting the BHA from excessive flow rates that could cause damage.
Solution Approach 2:
The flow diverter serves as an intermediary that regulates and distributes mud flow between different destinations. It acts as a flow management intermediary that can divert a controlled portion of the mud flow to the annulus for cuttings clearance while ensuring the remaining flow to the BHA remains within safe operational limits, thus protecting BHA components from damage.
3Productivity
If mud flow is diverted to the annulus at high velocity to clear cuttings efficiently, then cuttings lifting is improved, but mud loss through formation fracturing occurs
Solution Approach 1:
The system controls the parameters of diverted mud flow by using the flow diverter to regulate velocity and pressure. By adjusting the diversion parameters, the system maintains sufficient velocity for effective cuttings lifting while preventing excessive velocity that would cause formation fracturing and mud loss. The parameter control ensures optimal balance between clearance efficiency and mud conservation.
Solution Approach 2:
The flow diverter acts as an intermediary flow control device that manages the transition of mud from high-velocity drill string flow to annular flow. It mediates the flow characteristics to achieve effective cuttings transport while controlling the release parameters to prevent formation damage and mud loss, thus reducing substance loss while maintaining productivity.
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
Effectively clears drill cuttings from the annulus while maintaining drilling efficiency and safety by reducing the risk of formation damage through controlled mud flow diversion, ensuring proper cuttings transport and preventing drill string sticking.
Implementation Method 1
A flow diverter system that reduces the pressure and velocity of mud diverted to the borehole annulus by using a series of chokes and an actuation system to control fluid flow, dissipating hydraulic energy
Data Source
AI summary
A flow diverter including a bypass element to divert at least a first portion of drilling fluid from a drill string to the borehole annulus. The first portion of fluid, or bypass flow, may be provided to the borehole annulus to clear cuttings generated by a drill bit of a BHA. The remaining fluid flow, or BHA flow, may be expelled through the bottom of the BHA. The fluid discharged through the BHA may enter the annulus and flow upward with the fluid flow diverted through the flow diverter to aid in clearing cuttings. The flow diverter also includes a choke housing disposed concentrically within a drill collar and containing a plurality of chokes to regulate bypass flow. An actuation system may be coupled to the flow diverter to control opening/closing of the chokes and to measure flow rate of the first portion of fluid and/or the remaining fluid.