Submarine Wire-Line Coring Drill Rig Process for Sediment Extraction
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Solution Overview
Problem
Submarine wire-line coring drill rigs face challenges with hole collapse and difficulty in remote operation due to lack of mud protection and the need for precise drill pipe management, which are not addressed by standard drilling procedures for land or offshore rigs.
Innovation Solution
A sediment core-drilling process using a pressure-suction mode with a thin-walled annular cutting blade, seawater suction, and a high-pressure seawater washing pump to minimize disturbance and ensure efficient core extraction, along with a systematic approach for drill pipe management and hole cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If seawater is used as flushing liquid instead of mud, then the submarine wire-line coring drill rig can operate without mud protection equipment, but the hole wall protection ability deteriorates and hole collapse risk increases
Solution Approach 1:
The patent applies beforehand cushioning by using a casing shoe with a protective edge at the leading end to prevent hole wall collapse before it occurs. The casing shoe extends downward from the outer tube drilling tool and provides structural support to the hole wall during the drilling process, cushioning against potential collapse risks inherent in seawater-only flushing operations
2Productivity
If the drilling speed is increased to improve productivity, then the coring efficiency increases, but the disturbance to the sediment core sample increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the drilling speed parameter within a specific range of 20±2 mm/s. This parameter optimization allows the cutting blade to efficiently cut through sediments while minimizing disturbance to the core sample. The inner tube rotation speed is also controlled at 30-150 r/min to achieve the balance between productivity and sample integrity
3Object-affected harmful factors
If the inner tube is kept from rotating during drilling, then the sediment core sample disturbance is reduced, but the drilling force application becomes more difficult
Solution Approach 1:
The patent applies the intermediary principle by introducing a bearing combination at the upper part of the inner tube that acts as a mediator between the rotating outer tube drilling tool and the non-rotating inner tube. This bearing combination allows the outer tube to rotate for effective drilling while preventing rotation of the inner tube, thus protecting the core sample. The bearing combination transmits the necessary forces while maintaining the differential rotation state
4Productivity
If the drill rig is remotely controlled with high automation, then the operation efficiency increases, but the ability to carry out artificial intervention and treatment deteriorates
Solution Approach 1:
The patent applies self-service by designing the drill rig with automated systems that can perform drilling operations, monitor hole wall stability, and adjust parameters without continuous human intervention. The automated wire-line coring system can independently manage the drilling process, reducing the need for artificial intervention while maintaining operational effectiveness through remote control capabilities
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
This process achieves low disturbance and high efficiency in coring, suitable for remote operation, while maintaining safety and reliability by adapting to the unique conditions of submarine wire-line coring.
Implementation Method 1
drawing seawater from the drill pipe by the seawater suction cylinder
Implementation Method 2
switching the reversing valve to allow a water outlet of a pump to communicate with the inner hole of the drill pipe; switching on the pump and the drilling power head; cleaning a bottom of the drilled hole by using the outer tube drilling tool to wipe stairs at the bottom of the drilled hole
Data Source
Figure 1
Figure 2
AI summary
Disclosed is a sediment core-drilling process for a submarine wire-line coring drill rig, including 1) lowering the drill rig; 2) drilling in a pressure-suction mode; 3) drilling in a rotation-pressure-suction mode; 4) cutting sediment cores; 5) recovering a core inner tube; 6) cleaning bottom of hole; 7) punching before adding a drill pipe; 8) lowering another core inner tube; 9) adding the drill pipe; 10) punching after adding the drill pipe; 11) repeating the steps 2)-10) until a given hole depth is reached; 12) recovering the drill pipe and a wire-line coring outer tube drilling tool; 13) recovering the submarine wire-line coring drill rig. The core-drilling process provided herein is suited to working conditions without mud lubrication and mud protection for hole wall. This invention has advantages of low disturbance and high efficiency in coring and is suitable for remote operation.