GB2470762A

GB2470762A - Method for generating transverse vibrations in a well bore tool.

Info

Publication number: GB2470762A
Application number: GB0909616A
Authority: GB
Inventors: Lance Stephen Davis; Edward Docherty Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-04
Filing date: 2009-06-04
Publication date: 2010-12-08
Also published as: GB0909616D0

Abstract

Transverse vibrations are generated in a wellbore tool by rotating an eccentric weight 1. The rotation is coaxial with the longitudinal axis of the well bore tool 2. The offset mass can be rotated by fluid flow through a turbine, a hydraulic motor system, an electric motor or from a drive at the rig surface. The vibration frequency can be controlled by varying flow rate anddensity of fluid flowing through the tool, the weight and position of the eccentric weight and the blade profile and number of power stages of the turbine. The method is used to encourage movement of well bore solids away from a bottom hole assembly.

Description

Title: Vibration Generator: Down-hole Well-Bore Tool Welibore Tool In the process of drilling a wellbore and subsequently running Tubulars to target depth in well-bores, situations can arise where BHA's (Bottom Hole Assemblies) Drill-string Pipe, Casing or Liners experience difficulty in progressing along a wellbore this can be due to various conditions from welibore tortuosity, ledges, swelling Shale's etc. Some of these difficulties can be overcome by the process of Reaming' this requires axial reciprocation and also where possible rotation of the drill /casing / liner string to be applied, even in this situation cuttings of sand / gravel etc can begin to pack off the string behind a Drill Bit or Reamer Shoe or anywhere along the length of the BHA string and restrict the movement of the string causing the string to be neither reciprocated or rotated.

The invention described below is designed to generate a controlled transverse vibration in the wellbore string to which it is directly connected by threaded connections to reduce the instance of the packing-off of cuttings and sand and other debris and therefore will facilitate easier running of BHA Tubulars into and out of the wellbore for well bore completion.

Description: Vibration Generator

In the development of a well-bore tool which will generate a controllable transverse vibration within a wellbore there is a requirement to define a system which will have a known harmonic vibration or at least a known harmonic which can be controllable, this *....: control is required to be able to apply different magnitudes of generated transverse * S vibration to assist in the axial or rotational movement of a drill-string, casing or liner in the wellbore. S. * . * 550

* Such vibration may be generated by having a system which will rotate coaxially with / * within the well-bore and or drilling, casing / liner string which may be for example * ** powered by drilling fluid which is pumped through the string from the drilling rig at :. . surface to provide a controlled rotational speed of a system which may be e.g. a turbine * of axial flow reaction, impulse, cross-flow, vane type, or balanced positive displacement motors, these motor types are operational from very low to very high rotational speeds by varying the fluid mass flow rate from very low to very high through the weilbore.

The harmonics of the system may also be tuneable to a degree by e.g. varying the number of turbine stages and turbine blade profiles in an axial flow reaction type turbine to vary rotational speed for given variable flow rates and fluid densities. �

It is to be understood that any co-axial or axially offset power transfer system may also be considered for the motive source e. g. and electric motor either by direct or stored energy current or a direct mechanical or hydraulic top drive or rig floor system.

To generate a transverse vibration in a axial rotational system it is required to include an off-set weight of known mass in the rotating element of the axial system, this off-set mass will generate a transverse and rotational imbalance the frequency of which is controllable by varying the rotational velocity of the system or the mass of the off-set element i.e. low rotation speed will produce a low transverse vibration frequency and a high rotational speed will induce a high transverse vibration frequency, the required frequency being determined by actual rotational speed of the axially rotational motor system.

The rotational imbalance or frequency variation may also be tuneable by varying the mass and the radial location of the mass within the confine of the sweep of the rotoric element of the system.

For clarification; the location of the off-set mass (item 5, Fig 1) may be positioned either outboard or inboard of the supporting bearings and either at or near a connection or positioned away from a connection as may be desired to ensure string connection integrity.

The Vibration Generator tool may be positioned in the string either at the top or bottom or anywhere along the entire length of the string and can be used either singly or in as many multiples as required.

Fig 1: Shows a general I sectional arrangement of a down-hole rotational transverse vibration system.

Item I: Turbine Item 2: Well-bore BRA Drill / Casing / Liner string.

Item 3: Turbine co-axial rotating Shaft.

* Item 4: Bearings.

Item 5: Off-set Mass.

Item 6: BHA string connections. **.

* Fig 2 Shows a cross-sectional view identifying where an off-set mass may be radially . : located to generate transverse vibration on an axial rotation of the system.

* Item I: Off-set mass.

* Item 2: Well-bore BHA Drill / Casing I Liner String.

Item 3: Turbine axial rotating Shaft.

Claims

SS 0*5*5 * S S. * . * *5.SS * S. * S * *.S * * S..Claims 1) A method of generating controllable transverse vibration in a well-bore tool.
2) A method of generating controllable transverse vibration in a well bore tool by flowing wellbore fluid or air or foam or gas through a turbine or other hydraulic motor system.
3) A method of generating controllable transverse vibration in a wellbore tool by rotating a coaxial element by a direct electrical or electrical stored energy system e.g. batteries such as lithium-ion' or others.
4) A method of generating controllable transverse vibration in a welibore tool by rotating a co-axial element by direct top drive from the surface rig floor environment.
5) A method of generating controllable transverse vibration in a well-bore tool by co-axially rotating a fluid power driven axial flow reaction motor system.
6) A method of generating controllable transverse vibration in a well-bore tool by co-axially rotating a fluid power driven impulse motor system.
7) A method of generating controllable transverse vibration in a well-bore tool by co-axially rotating a fluid powered hydraulic piston type motor or other positive displacement motor system which is counter balanced for coaxially balanced rotation.
8) A method of generating controllable transverse vibration in a well-bore tool by co-axially rotating a balance vane motor system.
9) A method of generating controllable transverse vibration in a well-bore tool where the transverse vibration frequency is controllable & variable by varying the mass flow rate of a fluid through the tool.S *I..
10) A method of generating controllable transverse vibration in a well-bore tool * where the transverse vibration frequency is controllable & variable by varying the S.. radial off-set & weight of an off-set mass connected to the co-axial rotating : **. element of the system. *
* 11) A method of generating transverse vibration in a well-bore tool where the transverse vibration frequency is tune-able' by varying e.g. the blade profile of L: * an axial flow reaction turbine.
* 12) A method of generating transverse vibration in a well-bore tool where the transverse vibration frequency is tune-able' by varying e.g. the number of power stages of an axial flow reaction turbine.
13) A method of generating transverse controllable vibration in a well-bore tool where the transverse vibration frequency is variable by controlling the volumetric flow rate and or density of a fluid though the down-hole tool system.
14) A method of using generated transverse controllable vibration in a well-bore tool to encourage movement of well-bore solids away from settling around and in the vicinity of the vibration generating tool and other tools in the BHA of the well-bore.
15) A welibore vibration generating tool which is threadably connected to other welibore BHA connections.S S.... * . S. * S * S.. * * . S I.. SSS