WO2002046568A1

WO2002046568A1 - Rotary directional drilling device comprising deflecting means with slides

Info

Publication number: WO2002046568A1
Application number: PCT/FR2001/003683
Authority: WO
Inventors: Claude Mabile
Original assignee: Institut Francais Du Petrole
Priority date: 2000-12-07
Filing date: 2001-11-22
Publication date: 2002-06-13
Also published as: AU2002222017A1; FR2817905A1; FR2817905B1

Abstract

The invention concerns a directional drilling device comprising a shaft (5) driven in rotation, a drilling bit (3) driven in rotation by the shaft, a tubular body (7) coaxial with the shaft, at least two roller bearings (8, 9), co-operating between the body and the shaft, deflecting means including at least a sealed chamber consisting of at least two slide rails capable of moving in the slots provided in a mandrel arranged in the annular space included between the shaft (5) and the body (7).

Description

ROTARY DIRECTIONAL DRILLING DEVICE

COMPRISING A SLIDE BENDING MEANS

The present invention relates to the field of directional drilling, for example

for drilling oil exploration or exploitation wells, onshore or

offshore, mining or geothermal sources. In particular, the

device of the present invention applies to rotary drilling, that is to say to the

technique which consists in turning the destructive tool of the rock by

through the lining of drill pipes and a setting means

rotation located on the surface drilling rig, e.g. rotation table

or motorized injection head ("power swivel"). However, the invention does not exclude

not the use of a downhole motor (turbine or volumetric motor) placed in

the drill string.

We know, in the profession of driller, techniques to control

the trajectory of a drilled well. A first technique is to use a motor

bottom which rotates the drilling tool thanks to the energy taken from

the drilling fluid in circulation. Thus, drilling can progress without requiring rotation of all of the drill rods, but by sliding

longitudinal (sliding) as a function of the forward speed. In the neighborhood

of the drilling tool, an elbow fitting (bent sub), which can also be

integrated in the bottom motor (bent housing), shifts the axis of rotation of the tool by relative to the main longitudinal axis of the drill string, in particular

that of drill collars. This offset causes a trajectory to be carried out

deviated to drilling. The orientation of the elbow fitting in space allows

control the direction.

But such a technique has drawbacks for the operation of

drilling itself, in particular in that it requires stopping the rotation of the drilling string, which is detrimental to the speed of execution, the

quality and safety of the well, especially in the case of heavily drilling

deviated, or horizontal.

Also known, in particular from document EP-0209318 B1, are

diverted drilling means operational in rotary drilling. This document, here cited

in reference, uses the principle of a tubular element located close to the tool

drilling, concentric outside the drilling string at the end of

which is fixed the destructive tool of the rock. Said tubular element is

free to rotate around the lining thanks to rolling bearings and

can be kept substantially fixed in rotation relative to the ground, by

example by spring leaves. Between the internal rotary shaft and the inside of

the tubular element, flexion means of the rotating shaft are placed

by cushions inflated by a pressurized fluid.

The object of the present invention is to describe another device for bending the rotary shaft, presenting other advantages, for example ease

construction, better temperature resistance, miniaturization, etc. Thus, the present invention relates to a directional drilling device

comprising a shaft driven in rotation, a drilling tool driven in

rotation by said shaft, a tubular body coaxial with said shaft, at least two

rolling bearings which cooperate between the body and the shaft, means of

bending of the shaft placed between said bearings. According to the invention, the means of

bending comprise at least one sealed chamber constituted by at least

two slides which can move in slots provided in a

mandrel arranged in the annular space between the shaft and the body. The mandrel can be a cylinder coaxial with the shaft and the mandrel

cylindrical may have at least three longitudinal slots on its surface

external.

The cylindrical mandrel can be linked to the shaft by rolling bearings.

The cylindrical mandrel can be secured to the shaft so as to rotate

with him.

The cylindrical mandrel may be integral with the body and comprise at

minus three longitudinal slots on its internal surface.

Side plates can perform hydraulic seals

between the ends of the slides, the mandrel and the body.

Means for distributing a pressurized fluid can send the

pressurized fluid in at least one specific chamber. The pressurized fluid can be obtained by a pump driven by the

shaft rotation.

The device according to the invention can comprise means

that locate the device in space, locate the position of the

body relative to the longitudinal axis, control means which

send a signal to pressurize at least one chamber.

The device can also include means of transmission and

reception of a signal between the ground surface and the device, the signal

representing the location data of the device, a command

bending, or a measurement related to a drilling parameter.

The means of transmission and reception can communicate with

local electronic means disposed in said body.

The rolling bearing close to the drilling tool can be a ball joint,

the other bearing providing axial guidance.

The present invention will be better understood and its advantages

will appear more clearly on reading the description of the examples,

in no way limiting, illustrated by the attached figures below, among

which:

- Figure 1 schematically shows the principle of the device according to

the invention, Figures 2A and 2B schematically show a section

transverse bending means of the device according to the invention,

FIG. 2C shows another embodiment of bending means,

FIG. 3 shows a schematic longitudinal section of the bending means,

Figure 4 shows schematically the means of fluid distribution

hydraulic,

Figure 5 shows another variant of the present invention.

Figure 1 shows in section a deviation control device 1

of a borehole. This device 1 is fixed to the end of a drill string 2,

made up of stems and drill collars. A drilling tool 3 is screwed at the end of a shaft 5 integrally connected to the drilling string 2 by means of

connection 6. Tool 3 drills a well 4 by rotation, which rotation is

transmitted by the shaft 5 of the device 1 and the rotation of the whole of the

drill string 2.

The deflection device 1 comprises an external body 7 cooperating with

the shaft 5 by means of connections and bearings 8 and 9 at its two ends. The bearings 8 are of the ball joint type to allow the offset of

the drilling tool. The bearing 9 can also be a ball joint, but is

preferably non-swiveling, which is favorable for obtaining a design

as miniaturized as possible. Blades 10 act as anti- rotation, so that the body 7 is substantially fixed in rotation relative to

at the well. Other equivalent means may be used, telescopic pads

which are anchored on the wall, for example.

The deflection device 1 comprises means 11 for bending the shaft

turning 5. These means cooperate with the inside of the body 7 and the outside of

the rotating shaft 5 to apply a transverse force on the shaft 5 so

to deform it (illustrated by the dot representation in Figure 1) by

bending. The consequence of this deformation of the shaft is that the axis of the tool 3

is offset by an angle α relative to the main direction 12 of the well. according to

the orientation of the bending plane with respect to the fixed space, the trajectory of the

well can be steered.

A set of location sensors provides real-time

the coordinates of the well, which authorizes the sending of an order

corresponding to obtain or not a bending of the shaft, as well as

the orientation of the possible bending plane. These sensors are preferably

installed in a non-rotating body like body 7.

FIG. 2A represents a cross section at the level of the means

bending 11. The rotary shaft 5 is traversed longitudinally by a conduit

13 allowing the circulation of the drilling fluid. A mandrel 14, concentric

to the rotary shaft, has slots 15 distributed regularly over the circumference of said mandrel. Here, six slots have been shown spaced 60

degrees. Pallets or slides 16 are placed in the slots 15. This layout of six bedrooms 17a to 17f. Cross plates (not

shown in these figures) close these chambers at both ends of the

mandrel 14. Of course, sealing means, according to techniques

known to those skilled in the art, close these chambers by sealing

slides or pallets 16 on the internal surface 18 of the body 7, slides

or pallets 16 in the slots 15, the two ends of the pallets or slides

16 with the transverse closing plates at the end of the mandrel.

The principle of the invention is therefore apparent in FIGS. 2A and 2B where

the presence of a pressurized fluid in a chamber has been shown, by

example 17A, which gives a resulting radial force on the shaft 5 and therefore

a bending force corresponding to the deflection d shown in FIG. 2B. The

FIG. 2B illustrates the displacement of the mandrel 14 linked to that of the shaft 5. The

movement of the slots 15 therefore also causes that of the pallets or

slides 16 in said slots so that the slides 16 remain at

contact with the inner surface 18. The depth of the slots 15 is such that it

allows the radial play of the pallets or slides 16 as a function of the displacement

d. Return means 50 are arranged at the bottom of the slots for applying the

slides against the wall 18. FIG. 2C shows another form of the slides. In case the

displacement of the shaft 5 is low in the body 7, it is possible to use

slides of cylindrical section 51. The principle of construction and operation is exactly the same as that described from FIGS. 2A

and 2B.

FIG. 3 schematically shows the bending means 11 in section

longitudinal. The end plates 20 provide the seals with the

two sides of the pallets or slides 16, the surface 18, and the ends of the

mandrel 14. In an exemplary embodiment, these disc-shaped plates have a central bore so as to allow play 21 with the shaft 5 which

must move under the effect of hydraulic pressure in at least one of the

rooms 17a-17f. The reference p represents the depth of the slots 15.

We can make the parallel with the construction of vane pumps

variable flow which are also constituted by the cooperation of pallets,

a mandrel and slots to provide hydraulic chambers of

variable volumes depending on the offset of the pallet holder mandrel. These

pumps operate by accepting a certain leakage rate between the chambers

high and low pressure. The hydraulic regulation of this device

also includes means for draining and regulating the pressure.

FIG. 4 represents the hydraulic distribution to the bending means 11

shown schematically in this figure by a set of chambers 30 to which are

connected a set of oil inlet pipes 31 and a set of exhaust pipes 32. The references 33 and 34 represent the means of

oil distribution allowing high pressure to be sent to a room,

or a first set of rooms, and to purge the room, or the whole of chambers, diametrically opposite to the first set. The means of

distribution are connected to a pump 35 drawing oil into a tank

36 in which the purges 37 and 38 collect the oil at low pressure. A flow regulator 39 can be added to the circuit. Advantageously, the pump

hydraulic 35 is driven by the rotation of the shaft 5 relative to the part

exterior 7. Energy can also be used, directly or indirectly

drilling fluid circulating in the shaft 5.

There are several alternative embodiments of the present invention, depending on whether the flexing means 11 are linked with the rotation of the rotating shaft.

5 or are linked to the external body 7.

In the variant where the mandrel 14 does not rotate with the shaft 5,

rolling bearings must be inserted between the mandrel 14 and the shaft 5.

Thus, the chuck, pallet or slide assembly is substantially fixed by

relation to the body 7. There is no significant slip in this variant

pallets with respect to the internal surface 18, the only displacement being the

consequence of the radial displacement of the axis of the mandrel which causes the

sliding of the pallets in the slots, as well as a small displacement

lateral. In this variant, the closure plates 20 (FIG. 3) are

practically immobile compared to chambers 17a-17f, therefore the conduits

hydraulic fluid supply and drain can be directly

drilled in the plates 20 opposite each of the chambers. The current

variant is illustrated in Figure 3 where rolling bearings have been represented and referenced 40. In this variant, one can have another mode

embodiment (according to the representation of FIG. 5): the mandrel 14 is

integral with the body 7 (they can also be, in principle, one and

same part), the pallets or slides 16 resting directly on the shaft

turning 5. This construction theoretically simplifies the mechanism since

there is no need for rolling between the bending means and the rotating shaft.

However, the wear resistance of the pallets 16 is crucial and difficult to achieve. Sure

FIG. 5, the arrows 41 leading to the chambers represent the conduits

hydraulic fluid supply.

In the second variant, the construction of the mandrel assembly,

pallets or slides is similar to that of FIGS. 2A, 2B or 2C, but the mandrel is integrally connected (or forms an integral part) to the rotating shaft 5.

We are thus in the configuration of a vane pump (or motor) with

'mobile rotor. In this variant, the side closure plates 20

(equivalent to the housing of a vane pump) include the distribution means allowing the pressurization of chambers having the position

desired to obtain the determined direction of the bending force. An example

distribution can be a perforated plate with inlet ports (the other

plate being perforated with exhaust ports) distributed regularly over a

circle, said plate being stationary relative to the outer body 7. The

position of body 7 is identified in space, which makes it possible to identify the

inlet ports which must communicate high pressure to the chamber placed in front to apply the bending force in the desired direction. This

distribution principle means that at each turn, all the rooms pass

from low pressure to high pressure, when a diversion order has been

sent.

Taking into account the known general dimensions of drilling devices

directional, it is estimated that a displacement d of about 1 centimeter makes it possible to

control the direction of drilling.

The following advantages of the invention can be described by

compared to the prior art:

- the order can be finer because it is possible to have more

three pressure chambers, for example at least six;

- the order is more flexible thanks to the distribution means which

have fast response times; - the temperature limitation is that of the distributors and not

pillows ;

- the number of rooms makes up for any failure

one of the distributors;

- the construction method is well suited to a reduced annular space

between the tree and the outer body.

- sealing are known and solvable problems with

industrial solutions for vane pumps. The device includes sensors to identify the position of the

device in space, as well as the electronic means necessary for

coding of information sent to the ground surface using a system of

known transmission, for example what is called MWD.

Claims

1) Directional drilling device comprising a shaft (5) driven in

rotation, a drilling tool (3) driven in rotation by said shaft,

a tubular body (7) coaxial with said shaft, at least two bearings of

bearing (8, 9) which cooperate between said body and said shaft,

bending means (11) of said shaft placed between said bearings,

characterized in that said bending means comprise at least

a sealed chamber (17a-17f) consisting of at least two

slides (16) which can move in slots (15) provided

in a mandrel (14) disposed in the annular space between

said shaft (5) and said body (7).

2) Device according to claim 1, wherein said mandrel (14) is

a cylinder coaxial with said shaft and in that said cylindrical mandrel

has at least three longitudinal slots (15) on its surface

external.

3) Device according to claim 2, wherein said mandrel

cylindrical is connected to said shaft by rolling bearings (40). 4) Device according to claim 2, wherein said mandrel

cylindrical (14) is integral with said shaft (5) so as to rotate with

him.

5) Device according to claim 1, wherein said mandrel

cylindrical is integral with said body (7) and comprises at least three

longitudinal slots (15) on its internal surface.

6) Device according to one of the preceding claims, wherein

side plates (20) provide hydraulic seals between

the ends of the slides (16), the mandrel (14) and the body (7).

7) Device according to one of the preceding claims, wherein the distribution means (33) of a pressurized fluid send the

pressurized fluid in at least one specific chamber.

8) Device according to claim 7, wherein the pressurized fluid

is obtained by a pump (35) driven by the rotation of said shaft.

9) Device according to one of the preceding claims, which comprises

electronic means which locate said device in space,

identify the position of the body relative to the longitudinal axis,

control means which send a signal to put under

, pressure at least one room.

10) Device according to claim 9, which comprises means for transmitting and receiving a signal between the surface of the ground and

said device, said signal representing location data of the device, a flexion command, or a measurement linked to a

drilling parameter.

ll) Device according to claim 10, wherein said means for

transmission and reception communicate with means

local electronics disposed in said body (7).

12) Device according to one of the preceding claims, in which

said rolling bearing (8) close to the drilling tool is a ball joint, the other bearing (9) providing axial guidance.