AU2006200195A1 - Stabilizer with front reaming capacity - Google Patents

Description

57016 KMC:PFB P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: OMNI OIL TECHNOLOGIES Actual Inventor: ADEL ALI BASSAL Address for Service: COLLISON CO., 117 King William Street, Adelaide, S.A. 5000 Invention Title: STABILIZER WITH FRONT REAMING CAPACITY The following statement is a full description of this invention, including the best method of performing it known to us:

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0 Stabilizer with Front Reaming Capacity cnFIELD OF THE INVENTION 00oO The present invention relates to a Stabilizer with Front Reamer to be used to stabilize a drilling String during operation. The Stabilizer with Front Reamer of the present invention is directed to an arrangement that will stabilize the drilling string and at the same time gauge the drilled hole to size. The flexibility INO of this invention allows for increasing or decreasing the front hole gauging capacity according to need.

BACKGROUND OF THE INVENTION Both reamers and stabilizers have traditionally been employed in oil well drilling operations for the petroleum industry. Stabilizer with front reaming is to provide two main functions: The first function provided by the described device is to act as a reamer.

Reamer part is to cut formations to enlarge the bore hole to the desired size, which may be the original size of the bit in the case the drill bit wears to be under-gauged. However, even for new bits, reamers are employed to cut formations because the bit does not always drill a true circular bore hole and because of slight lateral shifting inherent in the drilling operation; that shifting leaves ledges and other distortions along the bore. Another need for a reamer is due to the interaction of drilling mud with the earth formation; which leads to formation swelling and hence diameter reduction.

The second function of this device is to keep the drill stem in the centre of the hole, which means the device acts as a stabilizer. Stabilizers are positioned above the drill bit to ensure that the drill bit stabilizer assembly drill a straight hole of the desired diameter. Maintaining the drill stem centered has many benefits. The primary benefit is to minimize unintentional hole-angle directional drilling.

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A stabilizer thereby extends the life of the drill bit by confining the drill string movement into the original hole size.

Ct oO 00 The present invention provides the public with an alternative to existing reamers.

Other objects and advantages of the present invention will become apparent Sfrom the following description, taken in connection with the accompanying IND drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.

SUMMARY OF THE INVENTION Stabilizers and Reamers are traditionally used in oil well drilling. These two tools are common in oil field drilling operations. The current invention relates to a new tool that can perform as a stabilizer for the drill string, and has a leading reamer that reams a wide range of diameters up to nominal bit size.

The front Reamer is designed on a conical body.

Reamers are used to cut formations to enlarge the bore hole to hole nominal size, which in most cases the original bit size, as in some cases the drill bit wears down to be under nominal size. However, even for new bits, reamers are employed to cut formations because the bit does not always drill a true circular bore hole because of slight lateral shifting inherent in the drilling operation; that shifting leaves ledges and other distortions along the bore.

Another need for reamers is due to the interaction of drilling mud with the earth formation; which leads to formation swelling and hence hole diameter reduction.

For the current invention, the reamer part is designed on a conical body which has the advantages of gradual engagement with the earth formation at any required rate depending on the angle of the conical part to ream the drilled hole, and open hole back to nominal size.

Opening the drilled hole back to nominal diameter as above eliminates or reduces the interference between the stabilizer part and the hole formations.

This results in reduction of the required torque to rotate the drill string, and consequently reduces forces, and heat generation due to friction with the well walls.

Therefore according to a first aspect of the present invention there is provided a reamer for use in association with a stabilizing element to the drill stem and a drill bit in drilling a hole in a rock formation, said stabilizer with front reaming having: a body having a through going bore for passage of drilling fluids there through; said body having a conical lower part adapted from connection to a drill string and a generally reamer part of diameter gradually smaller than said upper part, and said stabilizer part including plurality of wear surfaces located on an outer surface thereof that bear against a surrounding drill hole surface and a plurality of spaced apart, axially extending spiral flutes cut into said outer surface; wherein said wear surfaces include two or more stabilizing bands axially spaced along the stabilizer part.

The adoption of two or more bearing points, represented by the wear surfaces, provides for stability in the position of the reamer and thereby the drill assembly. Preferably, stabilizing bands axially spaced along the stabilizer part are separated by a region of reduced diameter By arranging hard reaming carbide inserts along the length of the conical body, the reamer is thus is use, brought to bear against the drilled hole-wall at circumferentially spaced positions. The surface of the reamer rubs against the hole-wall thereby ensuring to ream hole back to gauge.

Preferably, said wear surfaces are all studded with a plurality of hardwearing studs, for example carbide surface studs.

The stabilizer with front reaming of the present invention may be embodied as either a near bit stabilizer reamer in which the reamer part is adjacent the drill bit in use, or alternatively as a string Stabilizer reamer in which the reaming part is spaced along the drilling string from the drill bit.

Preferably, said spaced apart, axially extending spiral flutes cut into said outer surface are cut at a low angle relative to thereby minimize the extent of helical movement in fluid moving along the flutes.

In a particularly preferred embodiment of the present invention the spaced apart axially and spirally extending spiral flutes cut into said outer surface are milled out, and the distance between adjacent axially spaced wear surfaces are arranged such that, around the circumference of the reamer, a wear surface engages the surrounding hole wall at some point.

DESCRIPTION OF DRAWINGS The above and other objects, features, and advantages of the present invention will be apparent from the following accompanying drawings. In the drawings: Figure 1 shows the outer profile of the tool. It shows a conical reaming part and two stabilizing bands.

Figure 2 shows the tool after milling of the spiral flutes and insertion of wear inserts.

Figure 3 shows a three dimensional representation of the final assembled device.

Stabilizers and Reamers are traditionally used in oil well drilling. These two tools are common in oil field drilling operations. The current invention relates to a new tool that can perform as a stabilizer for the drill string, and has a leading reamer that reams a wide range of diameters up to nominal bit size.

The front Reamer is designed on a conical body.

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O Reamers are to cut formations to enlarge the bore hole to hole nominal size, Swhich in most cases the original bit size, as in some cases the drill bit wears Sdown to be under nominal size. However, even for new bits, reamers are 00 employed to cut formations because the bit does not always drill a true circular bore hole because of slight lateral shifting inherent in the drilling operation; t that shifting leaves ledges and other distortions along the bore. Another need for reamers is due to the interaction of drilling mud with the earth formation; which leads to formation swelling and hence hole diameter reduction.

Considering the figures there is illustrated a reamer for use in association with a stabilizing element to the drill stem and a drill bit in drilling a hole in a rock formation, said stabilizer with front reaming having a body with a through going bore for passage of drilling fluids there through; said body having a conical lower part adapted for connection to a drill string and a reamer part of diameter gradually smaller than said upper part. The stabilizer part has a number of wear surfaces located on the outer surface that bear against the surrounding drill hole surface. There are spaced apart, axially extending spiral flutes cut into said outer surface. The wear surfaces include two or more stabilizing bands axially spaced along the stabilizer part.

The adoption of two or more bearing points, represented by the wear surfaces provides for stability in the position of the reamer and thereby the drill assembly. The stabilizing bands, axially spaced along the stabilizer part, are separated by a region of reduced diameter Hard reaming carbide inserts are arranged along the length of the conical body. In use, the reamer is brought to bear against the drilled hole-wall at circumferentially spaced positions. The surface of the reamer rubs against the hole-wall to ream hole the back to gauge.

The wear surfaces are all studded with a of hardwearing studs, for example carbide surface studs.

The spaced apart, axially extending spiral flutes cut into said outer surface are cut at a low angle to thereby minimize the extent of helical movement in fluid moving along the flutes.

In an embodiment, the spaced apart axially and spirally extending spiral flutes cut into said outer surface are milled out, and the distance between adjacent axially spaced wear surfaces are arranged such that, around the circumference of the reamer, a wear surface engages the surrounding hole wall at some point.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognised that departures can be made within the scope of the invention, which is not to be limited to the details described herein but is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus.

Claims (7)

1. A stabilizer-reamer for use in association with a stabilizing element 00 to the drill stem and a drill bit in drilling a hole in a rock formation, said stabilizer-reamer having: Sa body having a through going bore for passage of drilling fluids there through; said body having a conical lower part adapted Sfrom connection to a drill string and a generally reamer part of INO diameter gradually smaller than said upper part, and said stabilizer part including plurality of wear surfaces located on an outer surface thereof that bear against a surrounding drill hole surface and a plurality of spaced apart, axially extending spiral flutes cut into said outer surface; wherein said wear surfaces include two or more stabilizing bands axially spaced along the stabilizer part.

2. A stabilizer-reamer for use in oil well drilling, said stabilizer including an outer surface symmetrical to the axis of rotation; said outer surface being generally parallel to said axis of rotation; said surface also including a plurality of hard carbide inserts or other hard material adapted to slow down wear on the stabilizer outer surface due to continuous rotation of the drill string and the contact with the well walls.

3. A stabilizer-Reamer as in claims 1 and 2 wherein there are right hand spiral grooves, each having an angular width, having a depth of several millimeters depending on the necessary mud flow required.

4. A stabilizer-reamer having a conical section at the bottom of the stabilizer section wherein the surface converges at an angle generally varies according to required reaming capacity.

5. A stabilizer-reamer as in claim 4 wherein hard dome tungsten carbide inserts are arranged circumferentially on the conical part around said axis of rotation.

6. A reaming stabilizer for use in boreholes including a body having respective recesses helically cut around an axis of NO O rotation Ssaid Stabilizer having an outer surface symmetrical to the axis of Srotation, said outer surface having a plurality of tungsten carbide 00 0inserts flush with the surface, said body having a conical part below the said stabilizer that has a Splurality of tungsten carbide domes protruding from the surface adapted to gradually ream the drilled hole.

7. A Stabilizer with front reaming capacity substantially as O hereinbefore described with reference to and as illustrated in the accompanying drawings. Dated this 18t day of January 2006 OMNI OIL TECHNOLOGIES By their Patent Attorneys COLLISON CO