Tubing elongation correction system & methods

Abstract

A surface processor uses an environmental profile to determine the sub-surface length of tubing disposed in a well bore. Information relating to tubing properties is stored in a memory module of the surface processor. The environmental profile includes data relating to well bore ambient conditions and the operating parameters of well equipment. Surface processor calculates the tubing elongation or length reduction corresponding to the environmental profile. Surface processor may repeat this process to develop a measured depth chart for a well. Logging operations performed in conjunction with the sub-surface length calculations allows formation data to be associated with the measured depth chart.

Description

[0001] This application is related to pending application Ser. No. 09 / 081,961, filed May 20, 1998 and entitled "Well System," which is hereby incorporated by reference. Further, this application claims the benefit of provisional application Serial No. 60 / 269,280 filed Feb. 16, 2001 and entitled "Length Correction System and Methods," which is also hereby incorporated by reference.[0002] Not Applicable.[0003] 1. Field of the Invention[0004] The present invention relates to a system for determining the drilled distance between the surface and a point in a well bore. More particularly, the present invention relates to a system using a processor that calculates true measured depth based on data received from surface sensors, downhole sensors, and in another aspect, the present invention relates to a method for using a tubular umbilical to determine the drilled distance between the surface and a point in a well bore. More particularly, the present invention provides a method for correcti...

AI Technical Summary

Benefits of technology

[0013] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.

Problems solved by technology

This is even more the case with water layers because recovery of water is rarely, if ever, profitable.

Moreover, it is usually very undesirable to inadvertently drain a gas or water layer because these fluids tend to flood a well to such a degree that a well remains nonfunctional until all the water or gas has been evacuated from the well.

Further compounding the inherent difficulties in this situation is that, in many instances, a pay zone may be less than fifty feet in a well bore that may be thousands of feet in length.

Inaccurate data could lead to unintended violations of regulatory rules and subject the well owner to fines or other penalties.

While these prior art MD survey techniques may be reliable for tubing formed of metals such as steel, however, such techniques do not give accurate logs for tubulars made of materials such as composites.

Tubulars made of non-metals, such as composites, are susceptible to significant length changes due to factors such as temperature, pressure and axial loadings.

Unfortunately, elevated temperatures, high operating pressures and complex compression and tension loadings are almost always present in a well bore environment.

An uncorrected MD log can present serious problems in later operations when equipment such as perforation charges are tripped downhole to initiate the drainage of a pay zone at P.sub.i.

Indeed, even during successive composite coiled tubing trips for the same operation, downhole conditions can vary to a point where it may be difficult to correlate logs of these successive trips.

Despite the critical need for accurate MD logs, the prior art does not disclose systems or methods that correct surface measurements of tubulars made of materials that deform when exposed to environmental factors.

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