What Else? - ISCWSA

DrillScan is an active member of the “Industry Steering Committee on Wellbore Survey Accuracy” (ISCWSA).

The ISCWSA seeks to dispel the confusion and secrecy currently associated with wellbore surveying and to enable the industry to produce consistent, reliable estimates of survey-tool performance in today's wells. This will be achieved through the production and maintenance of standards covering the construction and validation of tool error models.

Work focused initially on MWD systems. These provide a large portion of the total directional survey data worldwide and, because of their similarities between suppliers, are more amenable to specification standardization than other types of survey tool.

There is no formal membership in the committee and its meetings are open to all who wish to attend. The committee has held 25 meetings to date.

The results of the work on an error model for a basic directional MWD service was presented in SPE 56702 'Accuracy Prediction for Directional MWD' by Hugh Williamson at the 1999 SPE Annual Technical Conference and Exhibition in Houston, Texas, held from the 3-6 October 1999.

An updated version of this paper (SPE 67616) was published in the December 2000 edition of SPE Drilling and Completion (Volume 15, Number 4) on pages 221 to 233.

A gyro error model was produced and published in paper SPE 90408 'Prediction of Wellbore Position Accuracy When Surveyed with Gyroscopic Tools' by Torgeir Torkildsen, Stein Havardstein, John Weston and Roger Ekseth.

Depth issues were investigated and the results published as SPE 95611, "Quantification of Depth Accuracy", presented at the SPE Annual Technical Conference, Dallas, 9-12 October 2005.