BACKGROUND Field of the invention This invention concerns an activating tool for fast activation of equipment in a well.

Related and prior art

For retrieving oil and gas, wells through geological formations are used. The wells are lined with steel pipes that are cemented to the formations. A well can extendo from a few hundred meters to several thousand meters below the surface or a seabed, and it can have horizontal side branches.

The mixture of oil, condensate, gas, water, salts, other chemicals and debris from the formations exposes the steel pipes of the well for considerable corrosion, wear5 and tear. Hence, it is customary to insert production piping into the well through the casing.

Equipment to monitor corrosion, wear and tear, composition of production flow from different side branches, plugs, valves, etc., is set in the well for differento purposes at different times. When a side branch produces to little hydro carbons, it may for instance be desirable to shut it off.

In some instances, it is desirable to shut off all or parts of the well, or there is a need for turning on or off measuring tools in one or more sections. In such circum-5 stances, it is generally desirable to make the interruption of normal operations as short as possible.

It is known to suspend a tool from a wire with (e-line) or without (slickline) electrical power supply in order to open or close valves. It is also known to use coiled tubingo or pipe shaped strings having tools at their ends to activate/deactivate equipment in the well. A tool at the end of a steel pipe is suitable for use in lesser depths, because the rigidity of the steel tubing can be used to rotate elements of the equipment, e.g. for opening or closing valves. A wire cannot be used for rotation in the same manner. Also, in deeper wells, steel tubing cannot be used for precise activation of tools or equipment. In many cases, a tractor is used where steel tubing or wire are unsuitable.

In some cases, it is desirable to activate valves or other equipment to close or open a section in the well, or to perform measurements in the section. Using conventional equipment, a long time is required to localize each single well tool, activate or deactivate it, and continue to the next. This in turn leads to relatively long interrupts in normal operations for all or parts of the well. With interrupts of a shorter duration, it may for example be possible to perform a greater number of measurements in a given section during a year, such that the reliability of e.g. estimates of future production may be improved.

The problem to be solved is to provide robust equipment which can activate or deactivate equipment or tools in a well in a simple manner.

SUMMARY OF THE INVENTION

This problem is solved according to the present invention by a tool for activating equipment in a tool, distinguished by an inner cylinder disposed axially slidably and biased in an outer housing, at least one friction block retained by the inner cylinder and adapted to be radially biased against an inner wall in the well, at least one latching dog retained in the inner cylinder and biased radially outwards, which latching dog is adapted to activate equipment in the well, a locking sleeve fixed to the outer housing and disposed such that it covers the latching dogs in a first position and does not cover the latching dogs in a second position.

The tool can be attached to e.g. a wire, and be moved downwards in the well by attaching a weight to it in a customary manner. When the tool is at a predetermined location in the well, the outer housing is pulled upwards while the inner cylinder is retained by the friction blocks. Thereby, a sleeve is pulled away from the latching dogs, and is prevented from slipping back by a locking pin. The latching dogs are designed and retained such that they can activate equipment being passed by the tool when the latching dogs are in their outer position. The tool can be retrieved without operating equipment in the well, and the latching dogs can be turned 180° to deactivate equipment when the tool is moved through the well in the opposite direction of the direction used during activation.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is disclosed in greater detail with reference to the accompanying drawings, where similar reference numerals refer to similar elements, and where:

Figure 1 shows an activating tool in its locked state, and

Figure 2 shows the activating tool from figure 1 in an armed state.

DETAILED DESCRIPTION

Figure 1 shows the main elements in an activating tool according to the invention. An inner cylinder 120 is inserted into an outer housing, and is retained within the housing by a spring 160, which in figure 1 is disposed around a part of the cylinder 120, and engages a rear shoulder on the cylinder 120 extending radially outwards and a front shoulder on the outer housing extending radially inwards. It is noted that the cylinder 120 in another embodiment can be hollow.

The outer housing has in one of its ends an end piece 110 where the tool can be attached to a wire. The end piece 110 also has a collar for a fishing tool if an emergency retrieval should become necessary. The other end of the housing forms a sleeve 150, which in figure 1 covers and depresses radially biased latching dogs 130.

Radially biased friction blocks 121 are retained in the cylinder 120, and are forced against the surrounding pipe wall when the tool is inserted into a well bore. This gives a friction force proportional to the radial biasing force. This friction force acts directly on the cylinder 120, and not through the outer housing.

In figure 1 , a radially biased locking pin 140 engages an inner surface of the sleeve 150. In use, the activating tool is attached to a cable or wire, and sufficient weight is supplied to overcome the friction force from the clutching elements 121 , typically several hundred kg. When the activating tool as shown in figure 1 is run into a well bore in this manner, the latching dogs 130 are locked to the body of the tool by the sleeve 150. The latching dogs will, when in this position, not engage tools or equipment in the well.

At a predetermined location the tool is stopped, and the wire is used to pull the end 110 against the spring force from the spring 160. During this pull, the cylinder 120 is retained in the well by the friction force against the walls of the well, such that the outer housing can be moved relative to the inner cylinder 120 until the locking pin 140 is pushed outwards into a locking groove in the sleeve 150.

After this pulling movement, the activating tool is armed, as shown in figure 2. The latching dogs 130 are no longer depressed by the sleeve 150, and can thereby engage suitable grooves on other equipment and tools. The locking pin 140 prevents the sleeve 150 from returning and depressing the latching dogs.

When the pull is removed from the wire, the weights will once more be able to push the activating tool downwards into the well bore. However, now the latching dogs 130 engage all equipment and tools having profiles corresponding to the profiles of the latching dogs. Thereby, it suffices to convey one such tool downwards to activate equipment, for example for opening a series of valves that are operated by the latching dogs 130 one after the other.

In a preferred embodiment, the latching dogs are preferentially asymmetrically designed or retained, such that they operate equipment when passing in one direction, but not when they pass in the opposite direction. Hence, in this embodi- ment, the activation tool can be retrieved without equipment or tools in the well is operated, even when the tool is armed as shown in figure 2. If the valves in the above example are opened by an armed activating tool on its way downward, they will in other words not be closed again when the tool is pulled back. If the valves in the example above are to be closed after a period in their open position, the latching dogs in this embodiment will be turned 180° on the tool, which thereafter is run past all equipment to be operated. Only when the tool is pulled back towards the surface, and the asymmetrical latching dogs passes in the upward direction, the equipment in the well be operated by the latching dogs 130, e.g. in that the valves of the above example get closed.

In a variety of the preferred embodiment, the latching dogs are retained onto the tool at one of their ends such that they are inclined in the axial direction, and such that their distal ends are pushed outwards with a biasing force substantially less than the force required to operate the equipment. When such latching dogs 130 pass equipment in a first direction, they can engage grooves on the equipment, and a force sufficiently large to operate the equipment is transferred from the retainer, along the latching dog 130 to the equipment to be operated. When the latching dogs pass in a second, opposite direction, the well equipment will engage an inclined face of the latching dog. Because the latching dog is pressed outwards by a biasing force being less than the force required to activate the equipment of the well, the latching dog 130 will be depressed into a recess in the tool when it passes in this second opposite direction.

In an alternative embodiment, the latching dogs may be operative in both directions, e.g. in that they close a series of valves on their way down. Thereafter, the tool can remain until the valves are to be reopened by pulling back the tool.

As apparent from the description above, the pulling force required to lift the applied weight and to overcome the spring force from spring 160, and/or to overcome the friction against the wall of the well, is the only force that has to be transferred to the tool from outside. To transfer such a pulling force, it suffices to use a wire ("slickline"), but it is of course also possible to attach the tool to the end of a string of pipes or to use a tractor to dispose it. However, in most cases the easiest and less expensive alternative would be to use a wire (slickline) as disclosed.