NO20161434A1

NO20161434A1 - A hole forming tool

Info

Publication number: NO20161434A1
Application number: NO20161434A
Authority: NO
Inventors: Morten Lerbrekk; Sigurd Goa
Original assignee: Tyrfing Innovation As
Priority date: 2016-09-09
Filing date: 2016-09-09
Publication date: 2018-03-12
Also published as: WO2018048311A1; NO20190372A1; NO347771B1; GB2568432A; GB2568432B; GB201903691D0

Abstract

A hole forming tool (1) with a longitudinal axis (Y-Y) is configured for operation inside an inner casing (5). The tool comprises a plurality of hole forming units (9), connected by transmission means (7; 7', 11) to at least one hydraulic motor (6; 61). The said hole forming units (9) are arranged and configured for forming respective holes (H) through a casing wall (5a), and at least twoof said hole forming units (9) are arranged in the same plane (Pl), substantially perpendicular to the longitudinal axis.A hole forming tool (1) with a longitudinal axis (Y-Y) is configured for operation inside an inner casing (5). The tool comprises a plurality of hole forming units (9) connected by transmission means (7; 7 ', 11) to at least one hydraulic motor (6; 61). The said hole forming units (9) are arranged and configured for forming respective holes (H) through a casing wall (5a), and at least two said hole forming units (9) are arranged in the same plane (Pl), substantially perpendicular to the longitudinal axis.

Description

A hole forming tool

Field of the invention

The invention concerns the field of producing hydrocarbons from a subterranean reservoir. More specifically, the invention concerns a tool for forming a plurality of holes in a tubular, as specified in the preamble to claim 1.

Background of the invention

The prior art includes US 2015/0260020 A1, which describes a multi-directional drilltype device that can be shuttled vertically through well casings of various diameters to add new perforations at the desired spacing and positions along the casings to optimize well performance. The apparatus is especially suited to add perforations to well casings of existing vertical landfill gas (LFG) extraction wells. The apparatus comprises a centralizing skid and includes an electrical motor in a housing that is purged with inert gas and with an output shaft that rotates around a first axis. The motor output shaft drives plural drill assembly modules that have drill bits that rotate around an axis normal to the first axis and which reciprocate into and out of the apparatus. A plurality of individual drill assembly modules may be stacked atop one another, in which case one drill bit is associated with each drill assembly module and each drill assembly module is rotated relative to its adjacent module(s) so that the drill bits are driven in different directions, toward desired points around the cylindrical well pipe.

The prior art also includes US 2066 409, which describes an apparatus configured for being lowered into a well and equipped with a plurality of radial drills with means for rotating the drills and simultaneously moving them outwardly to drill perforations through the surrounding pipe or casing in the well. The drills are powered by a transmission shaft coupled to uphole driving means.

The prior art also includes US 4185 705, which describes a well-perforating tool for drilling holes in a well casing substantially from and at right angles to a vertical well bore within which the casing is disposed. The tool includes an elongate housing for insertion within the casing and having a detachable boot at one end thereof for centralizing the longitudinal axis of the tool within the casing. Two electric motors are disposed within the housing for rotating a flexible drill shaft, and advancing and retracting the flexible drill shaft with respect to the interior wall of the casing. The entire tool is supported by a cable which also includes power supply and signal lines for independently activating the motors from an above-ground control station and ascertaining the depth of drill shaft penetration. In one embodiment, the tool comprises gears and opposing shafts configured for simultaneous drilling of two opposed holes.

The prior art also includes US 4368 786, which describes a downhole drilling apparatus for drilling holes at right angles to a vertical well hole. The apparatus includes a tubular housing capable of being inserted in the well hole and containing at least one elbow tube or guide, and multiple tapered and splined, interlocking drilling segments which are rotatably stacked and nested as a segment string in the guide tube with the bottom one of the drilling segments designed for drilling through the well casing, the cement sheathing and into the production interval, and the top one of the segments cooperating with electric drive means to effect rotation of the nested segments inside the guide. The guide tube extends from the tubular housing wall upwardly and telescopes at the top of the segment string to permit slidable movement of the drive means inside the tubular housing and slidable and rotatable movement of the nested segments inside the guide tube and into the production interval. In a preferred embodiment of the invention a pair of guide tubes and cooperating segment strings is provided in the tubular housing for drilling two transverse drain holes simultaneously.

The prior art also includes US 2008/0135226 A1, which describes a milling assembly which can be delivered downhole on wireline. Once at the desired location, a processor extends centralizing and driving wheels to initially position the assembly. The assembly has a cutter end with one or more mills or cutters that can be selectively radially extended. The entire cutter end can be rotated in an arcuate manner over a predetermined range. One or more cutter can be extended at a time and driven. The wheels are driven either in an uphole or downhole direction at the same time the arcuate motion can take place. Using a processor, different shapes in a surrounding tubular can be made such as windows for laterals, a plurality of openings for production or interior locator surfaces to properly position subsequent equipment with respect to openings already made by the device.

The prior art also includes US 4421 183, which describes an apparatus for penetrating boreholes in oil wells. The apparatus includes a shaft rotatable by power means. First means may be operatively associated with the shaft and a rod to obtain a rotation of the rod by the shaft. Second means obtain a linear movement of the rod at each instant in accordance with a load imposed upon the rod at that instant. The second means may include means providing a slippage between the rotary movements of the shaft and the linear movements of the rod in accordance with the load on the rod. Third means are operatively coupled to the rod and are adaptable in configuration and position in accordance with the configuration of the bore hole to be penetrated. The third means may include an outer casing, a flexible boom movable within the outer casing and resilient means disposed within the flexible boom and movable within the outer casing. Means may rotate the resilient means in accordance with the rotation of the rod. Means may move the flexible boom linearly in accordance with the linear movement of the rod. Fourth means may be coupled to the flexible boom and the resilient means for operation in accordance with the linear movements of the flexible boom and the rotary movements of the resilient means. The fourth means penetrate the bore hole.

The prior art also includes US 1070 336, which describes an apparatus for perforating casings. The apparatus comprises rotary perforating wheels, whereby a plurality of longitudinal perforations may be formed in the casing when the apparatus is moved in one direction.

The prior art also includes US 2013/0319651 A1, which describes a hydro-mechanical slot-type perforator for simultaneously performing at least two slots in a production column. The perforator includes a casing, upper and lower pistons movable within the casing, a cutting unit driven by the pistons and carrying extendable cutting tools, and, optionally, a retractable mechanism fixing the perforator for transportation. The extension is provided by rotatable shackles, or balance beams, or a combination thereof. The lower piston is moved by pressurized fluid supplied through hydraulic channels or a hydraulic system, made in the casing. The shackles rotate around axles being spaced apart, or coincided. The cutting tools can be mounted on the shackles' movable parts, and, when mutually interacted, oppositely extend the cutting tools during countermovement of the pistons. The cutting tools can be mounted in the balance beam's shoulders, or can represent sharp edges thereof.

There is a need for an improved device for making multiple perforations in a wellbore tubular, such as an inner casing, in a controlled and efficient manner.

Summary of the invention

The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a hole forming tool having a longitudinal axis and configured for operation inside a first tubular having a wall, and comprising a plurality of hole forming units, connected by transmission means to at least one hydraulic motor; said hole forming units being arranged and configured for forming respective holes through said wall; at least two of said hole forming units being arranged in the same plane, substantially perpendicular to the longitudinal axis.

In one embodiment, at least two of said hole forming units are arranged in opposite directions in the same plane. The hole forming tool may comprise three or more hole forming units, arranged circumferentially with respect to a housing perimeter. In one embodiment, the hole forming units and hydraulic motor are arranged in a tubular housing, said housing having openings configured to correspond with respective hole forming unit locations.

In one embodiment, the hole forming tool comprises hole forming units arranged in multiple planes substantially perpendicular to the longitudinal axis, and wherein each plane comprises two or more hole forming units. The hole forming units may be operated independently of each other. The hole forming tool may comprise a plurality of hydraulic motors, drivingly connected to hole forming units via drive means, and each motor being connected to a flow manifold via piping.

In one embodiment, the hole forming units are arranged at regular intervals around the tool periphery and hence provide for a self-centralizing tool, without the need for anchors, slips, skids, and the like.

The hole forming units may be drilling tools or milling tools.

The invented tool and method are particularly useful for forming holes in a liner or casing installed in a subterranean wellbore. The invented tool and method provides for forming (e.g. drilling, milling, jetting) multiple penetrations in the liner or casing without damaging the wall (i.e. maintaining the structural integrity) and without damaging other liners or casings.

Brief description of the drawings

These and other characteristics of the invention will become clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached schematic drawings, wherein:

Figure 1 is a part-sectional side view of an embodiment of the invented tool, in operation in a wellbore;

Figure 2 corresponds to figure 1, and illustrates the invented tool having been moved a distance inside the wellbore;

Figure 3 is a part-sectional side view of another embodiment of the invented tool, in operation in a wellbore; and

Figures 4a, 4b and 4c are cross-sectional drawings of the tool housing, illustrating various penetration unit configurations.

Detailed description of a preferential embodiment

The following description will use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, ”upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

Figure 1 illustrates an embodiment of the invented tool 1, in operation in a wellbore W. The wellbore W is formed in a subterranean formation S, and is lined with an outer casing 4, installed in a manner known in the art. An inner casing 5 is installed inside the outer casing, also in a manner known in the art. The annulus A formed by the casings may be filled with cement (not shown).

The tool 1 is conveyed inside the inner casing 5 on a drillpipe 3 extending from an uphole assembly (not shown). The tool comprises a housing 2, inside of which a plurality of penetration units 9 is arranged. The penetration units 9 are arranged in a designated housing 8. The penetration units may be drilling tools or milling tools, or any other tool capable of forming a hole in the casing wall 5a in a controlled manned, without damaging other parts of the wall.

Several penetration units 9 are arranged in the same plane (perpendicular to the tool longitudinal axis Y-Y). In the embodiment illustrated in figure 1, four penetration units 9 are arranged, at regular intervals, in three different planes P1, P2, P3. It should be understood that the invented tool may comprise a plurality of penetration units in fewer or more planes. That is, when assembling the tool for a given application, the number of planes (P1to Pn), and hence the length of the tool, is determined based on the given requirements. The tool is configured such that penetration units 9 within each plane may be operated independently of each other.

Referring also to figure 4a, the penetration units 9 may be extended and retracted (out of and into the tool housing 2) independently of each other. Required control means and sensing means are not illustrated, as such means are known in the art. Figure 4b illustrates an alternative embodiment, in which two penetration units 9 are arranged in the same plane. Figure 4c illustrates yet another embodiment, in which the penetration units 9 are arranged in the same plane. A common feature of these embodiments is that the penetration units are arranged at regular intervals around the tool periphery and hence provide for a self-centralizing tool, without the need for anchors, slips, skids, and the like. The tool may also have a radial dimension such that the distance between the tool body and the inner casing wall is small. A typical tool radial dimension (OD) is 1⁄4” less than the inner casing inner diameter. This gives a 1/8” clearance on all sides. The invention shall not, however, be limited to such dimensions.

Also arranged inside the housing 2 is a hydraulic motor 6, connected via an axial drive shaft 7 (and required gears; not shown) to each of the penetration units 9. The hydraulic motor 6 is powered by fluids, for example pressurized drill fluids via the drillpipe 3, in a manner known in the art.

Arranged on the housing outer and lower side is a magnet 13, configured to collect cuttings and swarf created by the drilling or milling operations.

Figure 2 illustrates how the tool (1) has formed a plurality of holes H in the casing wall 5a, and been relocated to a new location in order to form a new set of holes.

Figure 3 illustrates another embodiment of the invented tool. Here, the penetration units 9 are powered by two smaller hydraulic motors 6’, via an axial drive shaft 7’ and radial drive shafts 11. Each of the motors 6’ are connected to a flow manifold 10 via piping 12. It should be understood that the tool may comprise more than two hydraulic motors 6’.

In operation, the tool 1; 1’ may be activated to form multiple holes in the inner casing wall 5a, thus providing access to the annulus A (for flushing operations, etc.). The perforation units 9 are only extended sufficiently far to penetrate the casing wall 5a, but not as far as to the outer casing 4.

Although the invention has been described in relation to forming holes in a liner or casing installed in a subterranean wellbore, it should be understood that the invention may also have other applications.

Claims

1. A hole forming tool (1) having a longitudinal axis (Y-Y) and configured for operation inside a first tubular (5) having a wall (5a) , and comprising:

- a plurality of hole forming units (9), connected by transmission means (7; 7’, 11) to at least one hydraulic motor (6; 6’);

- said hole forming units (9) being arranged and configured for forming respective holes (H) through said wall (5a);

- at least two of said hole forming units (9) being arranged in the same plane (P1), substantially perpendicular to the longitudinal axis.

2. The hole forming tool of claim 1, wherein at least two of said hole forming units (9) are arranged in opposite directions in the same plane (P1).

3. The hole forming tool of claim 1, comprising three or more hole forming units (9), arranged circumferentially with respect to a housing perimeter.

4. The hole forming tool of any one of claims 1-3, wherein the hole forming units (9) and hydraulic motor are arranged in a tubular housing (2), said housing having openings configured to correspond with respective hole forming unit locations.

5. The hole forming tool of any one of claims 1-4, further comprising hole forming units arranged in multiple planes (P1- Pn) substantially perpendicular to the longitudinal axis, and wherein each plane comprises two or more hole forming units.

6. The hole forming tool of any one of claims 1-5, wherein the hole forming units may be operated independently of each other.

7. The hole forming tool of any one of claims 1-6, further comprising a plurality of hydraulic motors (6’), drivingly connected to hole forming units via drive means (7’, 11), and each motor (6’) is connected to a flow manifold (10) via piping (12).

8. The hole forming tool of any one of claims 1-7, wherein the hole forming units are arranged at regular intervals around the tool periphery and hence provide for a selfcentralizing tool, without the need for anchors, slips, skids, and the like.

9. The hole forming tool of any one of claims 1-8, wherein the hole forming units (9) are drilling tools or milling tools.