Ejector Pump Drill Bit Pressure Control

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Solution Overview

Problem

Existing drill bit pumps fail to effectively limit fluid pressure against the drilling surface, risking fracture opening and leakage of drilling fluid into rock formations, and are often integrated into the drill bit, limiting drill bit selection and adaptability.

Innovation Solution

A pump positioned between the drill bit and drill string, directing the entire fluid flow through ejector nozzles directed away from the drill bit, creating a pressure drop and ensuring fluid circulation for cleaning, with bores connecting the annulus to the drill bit nozzles to maintain pressure within safe limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If drilling fluid is pumped at high pressure to clean the drill bit, then hole cleaning efficiency is improved, but fluid pressure against the drilling surface increases causing risk of fracture opening and leakage

Engineering Contradiction:

Improvehole cleaning efficiencyVSAvoidfluid pressure against drilling surface

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The fluid flow is segmented into two separate paths: one path directs fluid through ejector nozzles away from the drill bit for pressure relief, while another path directs fluid through bores to the drill bit nozzles for cleaning. This segmentation allows the system to achieve both high cleaning efficiency and pressure limitation simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The ejector pump acts as an intermediary device between the drill string and drill bit. It receives high-pressure fluid from the drill string, creates a pressure drop, and then delivers fluid to the drill bit nozzles through bores. This intermediary mechanism enables pressure reduction while maintaining effective cleaning flow.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If a pump is integrated into the drill bit to improve cleaning, then hole cleaning is enhanced, but drill bit selection and adaptability are limited

Engineering Contradiction:

Improvehole cleaningVSAvoiddrill bit selection

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The pump is extracted from the drill bit and repositioned in the drill string above the drill bit. This extraction allows the drill bit to remain a standard, interchangeable component while the pump provides enhanced cleaning functionality. The drill bit can now be selected based on geological conditions without being constrained by integrated pump designs.

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If high pressure is used to flush cuttings up the annulus, then hole cleaning is improved, but the risk of breaking open fractures in the rock increases

Engineering Contradiction:

Improvehole cleaningVSAvoidrisk of fracture opening

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Instead of directing high-pressure fluid directly at the drill bit and drilling surface, the system inverts the approach by using ejector nozzles to direct high-pressure fluid away from the drill bit. This creates a pressure drop that limits the pressure acting on the drilling surface, thereby reducing the risk of fracture opening while maintaining effective hole cleaning through the alternative flow path.

Inventive Principle:

Principle #13The other way round (Inversion)

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 solution effectively limits pressure on the drilling surface, ensuring efficient hole cleaning and preventing fracture opening, while allowing for standard coupling and adaptable drill bit selection.

Implementation Method 1

directing the entire fluid flow of the drill string to at least one ejector nozzle which has its outlet directed away from the drill bit in an annulus between the drill string and the borehole

Methodology Applied

Scientific EffectPressure drop: Pressure Drop

Implementation Method 2

directing a side flow from the internal bore of the drill string to ejector pumps placed externally on the drill bit

Methodology Applied

Scientific EffectJet effect: Jet

Implementation Method 3

at least one bore extending between the annulus on the outlet side of the ejector nozzle to the nozzles of the drill bit

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS9376874B2Pump positioned at a drill bit

Publication Date: 2016.06.28 ING NILS REIMERS AS

AI summary

An ejector or jet pump is provided for use in the drilling of wells to prevent the total fluid pressure at the bottom of the borehole from reaching a level which constitutes a risk of cracking the rock or sediment being drilled, thus resulting in leakage and circulation failure. The pump is placed between the drill bit and the drill string and provided with nozzles directed in such a way that low pressure is established externally at the drill bit. The pump is operated by the drilling fluid which is supplied in the normal way through the drill string. The pressure difference across the pump is used to draw a secondary flow of drilling fluid from the borehole through internal bores in the pump to the nozzles in the drill bit. This fluid flow provides necessary cleaning of the drill bit and drilling surface.