This application is the U.S. national phase of International Application No. PCT/EP2015/055506 filed 17 Mar. 2015, which designated the U.S. and claims priority to EP Patent Application No. 14160528.7 filed 18 Mar. 2014, the entire contents of each of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a method for verifying a well model. Furthermore, the present invention relates to a well model verifying apparatus, to a well model verifying system and to a computer readable storage medium.

BACKGROUND ART

An existing well for production of hydrocarbon-containing fluid may be represented by a series of data values in order to facilitate downhole operation. For example, during the design phase (i.e. before drilling), the well bore is defined in terms of dimensions and directions. Typically, these data values are arranged in a table so that the entire well is represented numerically. During the drilling operation, new values may be added to the table so that the table also includes real values obtained during the drilling operation. An additional table may also be provided including data relating to the completion, i.e. information about casing length, casing components etc.

Once the well is producing, or even in the pre-production phase, e.g. during completion, it may be necessary to perform various operations downhole. These operations require that tools are submerged downhole, and typical tools include perforators, key tools, stroker tools, cleaning tools, logging tools, etc. In order to provide efficient and safe operation of such tools, it is beneficial to know as much as possible about the downhole environment, especially at the position of the required operation.

Should the well be in need of a tool operation, it is therefore important to determine the position and the expected conditions downhole. Before the operation, the table may therefore be accessed to confirm well characteristics—the table may e.g. reveal that the tool may be able to pass without any restrictions, as well an expected temperature range below the maximum operation temperature of the tool. This kind of information is then used to decide whether to perform the operation or not, and using which tools.

In view of the above, the accuracy of the well tables is of high importance. Should e.g. the actual temperature be higher than the corresponding table specification, the tool electronics may be damaged or even completely destroyed. Another possibility is that a restriction is not defined in the table, while actually being present. In such cases, the tool may be stuck downhole.

Although well data facilitates and improves tool operation, there is a need for new methods and apparatuses for verifying the well data in order to avoid the problems described above.

SUMMARY OF THE INVENTION

It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved method and apparatus for verifying the well data in order to avoid the problems of a malfunctioning tool or the tool getting stuck.

The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by a method for verifying a well model, comprising the steps of:receiving stored well data of an existing well,forming a model based on the received well data,submerging a tool for performing a work task into the existing well, wherein the tool is arranged to sense present well characteristics when submerged,receiving tool data corresponding to the presently sensed well characteristics from the tool, said tool data representing downhole properties relevant to downhole operation and performance of the tool, andperforming a confirmation check by comparing the well data of the model with the tool data.

Preferably, tool data represents downhole properties associated with, or relevant to, downhole operation and performance of the tool. Hence, the confirmation check will provide valuable information regarding the accuracy of the well model, wherein the level of accuracy is provided for the well characteristics relevant for the tool operation and performance.

Throughout this specification, an existing well is to be interpreted as a well into which a downhole tool may be submerged. The existing well may thus be a well at least partly drilled. The existing well may also be a fully drilled well, however having no or only some part of it completed, i.e. being provided with a casing. The existing well may also be a fully completed well ready for production, be in production, or be in the process of being reviewed in order to produce again.

The method according to the present invention may further comprise the step of controlling the operation state of the tool based on the output from the confirmation check.

Said well data may comprise survey data obtained during designing the well, and/or survey data obtained during drilling of the well, and/or completion data, and/or intervention data obtained during well operation, and/or wellbore characteristics including temperature and/or pressure and/or flow.

Moreover, the well data may comprise survey data and at least one of completion data, intervention data, or wellbore characteristics.

In an embodiment, said model may be a 3D model.

Further, the model may represent at least a predetermined extension of the well.

The step of forming the model may further comprise the step of loading predetermined data representing tool characteristics into the model.

Also, the step of receiving tool data may be performed continuously or at regular intervals during operation of the tool.

The method as described above may further comprise the step of loading the received tool data into the model after the step of performing a confirmation check.

Moreover, the step of loading the received tool data may be performed repeatedly, continuously or at regular intervals.

In an embodiment, the model may be updated after each repetition.

Further, the method as described above may further comprise the step of processing tool data so that it corresponds to wellbore characteristics.

Also, the method as described above may further comprise the step of extrapolating the model from the received tool data.

In addition, the method as described above may further be configured to allow multiple users, or stakeholders, to access the model, so that a first user may access a first part of the model, while a second user may access a second part of the model simultaneously in a multi-user mode. The first part and the second part may overlap, e.g. in cases when the first part is a zoomed-in portion of the second part.

Furthermore, the multi-user mode may be available while receiving tool data and performing a confirmation check by comparing the well data of the model with the tool data.

The method may further comprise the step of transmitting a control signal to the submerged tool for changing the operation state of the tool.

The present invention also relates to a well model verifying apparatus, wherein said apparatus is configured to:receive stored well data of an existing well,form a model based on the received well data,submerge a tool for performing a work task into the existing well, wherein the tool is arranged to sense present well characteristics when submerged,receive tool data corresponding to the presently sensed well characteristics from the tool, andperform a confirmation check by comparing the well data of the model with the tool data.

Preferably, tool data may represent downhole properties associated with, or relevant to, downhole operation and performance of the tool.

Furthermore, the present invention relates to a well model verifying system comprising a downhole tool and a well modifying apparatus as described above.

Finally, the present invention relates to a computer readable storage medium encoded with instructions that, when loaded and executed on a controller of an apparatus, may cause the method as described above to be performed.

It should be realised that the embodiments of the method may also be realised for other aspects of the invention, such as the apparatus.

