In a variety of well related operations, tools are used to carry out desired tasks at downhole locations. For example, different types of tools are used to drill wellbores, to deploy tubing and other equipment downhole, to perform testing operations, and to conduct servicing operations. During these operations, a tool occasionally becomes stuck in the wellbore or disconnected from its conveyance. If the tool is stuck in the wellbore, the tool can be cut free to enable retrieval of the conveyance and other downhole equipment.
To retrieve the tool left downhole, a fishing operation is conducted in which a fishing tool is deployed downhole from a surface rig. The fishing tool comprises a latching or attachment end designed to engage the tool, i.e. fish, to be retrieved. However, attachment of the fish can occur deep within the wellbore which makes it difficult to determine whether the fishing tool has contacted and adequately engaged the fish. Many hours of rig time can be wasted in withdrawing the fishing tool to discover the fishing expedition was not successful.
In general, the present invention provides a system and method to verify attachment of a fishing tool with a fish. The fishing tool comprises a latching mechanism to latch onto the fish to be retrieved and a detection device to verify connection of the latching mechanism. The detection device provides a signal uphole to verify attachment of the fish.
Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present invention relates to a system and methodology for performing a fishing operation. The system and methodology are used to provide an indicator as to when a well tool, i.e. fish, is engaged with the fishing tool. The indicator may be in the form of a signal provided uphole when the fishing tool is engaged with the fish. The signal also can be continually provided uphole while the fish is pulled from the well to inform an operator that the fish remains attached to the fishing tool. The ability to provide this indication to an operator helps avoid withdrawal of the fishing tool without the fish being attached, thus preventing wasted rig time.
In one embodiment, a fishing tool is deployed downhole into a wellbore via a conveyance, such as a coiled tubing fishing tool conveyance. However, other types of conveyances, including drill string, wireline and other conveyance mechanisms, can be used. The fishing tool usually is deployed downhole through a tubing, such as a casing or a production tubing positioned within the casing. The fishing tool comprises a latching mechanism for engaging and gripping the fish and a cooperating detection device that is able to provide, e.g. transmit, a signal uphole indicating the latching mechanism has engaged or latched onto the fish. A signal can be sent uphole to an operator to indicate full engagement of the fishing tool with the fish, and this signal also can be provided during withdrawal of the fish to indicate continued attachment of the fish to the fishing tool. Depending on the type of detection device used, the signal can be an individual signal, a constant signal, or an intermittent signal.
Referring generally to in
The fishing tool 22 is moved downwardly along a wellbore 28 and often down through a tubing 30, such as a well casing. In other applications, tubing 30 may comprise production tubing or other tubing positioned in wellbore 28, often within a surrounding casing. Fishing tool 22 is appropriately sized for movement through the tubing as necessary for a given application. As illustrated in
In the embodiment illustrated, fishing tool 22 comprises a latching mechanism 36 designed for attachment with fish 26 when moved into engagement with fish 26, as illustrated in
Fishing tool 22 further comprises a detection device 38 positioned to detect when fishing tool 22 has latched onto fish 26 and to provide an appropriate signal uphole indicating the attachment. By way of example, detection device 38 may comprise a switch 40, such as a contact switch, appropriately positioned so that it is automatically switched upon full engagement of fishing tool 22 with fish 26. The detection device 38 is then able to output a signal uphole indicating fishing tool 22 has been latched onto fish 26. By way of example, the detection device 38 may be a powered device able to output the signal, or the detection device 38 can simply be used to complete a circuit that extends uphole to the surface location 34.
In the embodiment illustrated in
Regardless of the specific type of communication line 44, detection device 38 may be a constant signal device able to output or convey a constant signal to display system 42 while fishing tool 22 is attached to fish 26. By way of example, detection device 38 may comprise contact switch 40 that is switched upon full engagement of the fishing tool 22 with the fish 26 to enable transmission of a constant signal during the attachment. Thus, an operator is provided with an indication that the fish 26 remains attached during the entire retrieval process as the fish is withdrawn from wellbore 28.
In alternate embodiments, the detection device 38 may be of a design that enables output of the signal only upon initial engagement of fishing tool 22 with fish 26. Other designs enable the detection device 38 to provide periodic or intermittent signals uphole indicating retention of the fish 26. This latter approach can be useful when the fishing tool 22 is not a smart tool and does not have an electrical line or fiber-optic cable extending to the surface.
As illustrated in
The system and methodology can be used to provide an operator with better information during a fishing operation. Knowledge of the status of the well tool fished from a downhole location enables more consistent and efficient fishing operations. It should be noted that the specific size, configuration and components of the fishing tool 22 can vary according to the environment and according to the type of tool that is to be fished from the wellbore. Furthermore, the configuration of the detection device also can vary according to the desired signal output, available communication lines, environment, and other factors that affect the overall operation.
Accordingly, although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Such modifications are intended to be included within the scope of this invention as defined in the claims.