An Improved Analysis of Axial Force Along Coiled Tubing in Inclined/Horizontal Wellbores

Abstract

Thm paper was prepared for presentabon at the 19S6 SPE Intemabonal ConfereM on Hcmzontat Well Technology held m Calgary, Canada, 18-20 Novem* 19% This papr was selected for presentawan by an SPE Prqrem Committee follovmg rewew of Inlormabcm cmtamed m an abstraci Submitted by the author(s) Contents of thm papw, as presented, have not been rewewed by ths %clely of Petroleum Engineers and are subject to wrractmn by the author(s) Th!s material, as presented, does not necessarily reflect any pmbon of Ihe Scuety of ptmleum Engineers ds oficars, or membars Papers presented at SPE meettngs are subject to publcatmn rewew by Edntortal Committees of the .?,c.aety of Petroleum Engineers Penn IssIcmto capy IS restricted to an abstraci of not more than 300 words IllustratIons may not be cop!ed The abstract should contain mnsp!cvous acknowledgment of where and by whom the paper was presented Whte Libfanan, SPE, P O. Box 833=, Rchardson, TX 75083 -3e3S, U S A fax 01-214-952-9435 AbstractThis paper presents an improved mathematical model for the axial force calculations along coiled tubing (CT) while drilling in inclined and horizontal wellbores. This new mathematical model is more general as it includes three types of coiled tubing configurations: straight, postbuckling "snaking", and helical. The equations for predicting the axial force under "snaking" configuration are believed to be presented for the first time. The "snaking" configuration of CT is of practical importance as it is a stable configuration for a wide range of axial loads. Several numerical case studies are provided to show the usefulness of the proposed axial force transfer model. The influences of friction, coiled tubing and wellbore size on the axial force predictions are described and presented in graphical form. Finally, a number of laboratory experimental results validate the proposed axial force transfer model as long as the effect of residual bending is not significant.

Buckling of Tubulars Inside Wellbores: A Review on Recent Theoretical and Experimental Works

“…These results, showed in Table 4, are the same presented previously in Ref. 45 (Table 3.) In Reference 47, buckling of pipes in curved wellbores was once again investigated.…”

Drill-String and Casing Design for Horizontal and Extended Reach Wells - Part I

“…An interpretation 10 of those results suggests that they were derived from different situations or, as better explained in Ref. 3, different loading stages. Table I and II summarize This will be a good guide in terms of buckling prediction for inclined/horizontal wells.…”

“…3, buckling occurs when the effective compressive load exceeds some critical value. There are a number of articles 3,4,5,6,7,8,9 dealing with models for prediction of the critical buckling force. Those models simulated buckling for different wellbore configuration such as vertical, inclined, curved and horizontal.…”

Which Material is Less Resistant to Buckling: Steel, Aluminum or Titanium Drill pipe?

“…Eq.3 has been verified in laboratory but is valid for a given axialcompressive load range (Martinez et al 21 2000). To take into account this additional contact force caused by buckling, the current practice is to include this contact force into a conventional torque-and-drag model 22 . However, this practice can give only some approximation of torque and drag increase caused by buckling.…”