Marking of New Cables

Further to the previous paper on marking of new cables which we published about two and a half years ago, we have now had an opportunity to review the information and recommendations made in that paper, and we suggest the procedure be revised as follows.

From observation of actual stretch in new cables which have been returned for remarking after ten or fifteen runs, we know that a new 15/32" seven conductor cable accrues a 'permanent stretch' of about 2 1/2 inches per 100 feet. This equates to a permanent stretch of about 0.21%. In order to compensate for this stretch we have been marking brand new cables at a tension of 4,000 ids, rather than at 1,000 lbs at which most cables are normally marked. (On a 1S/32" cable this additional 3,000 lb< over pull actually stretches the cable 3 x 0.77ft per 100ft 2.31'VlOOft, and therefore the marks are actually being put on the cable 2.31" short If their length was to be checked at l,000 lbs.)

Naturally the total permanent stretch of 0.21% does not all build up on the first run in the well, but builds up progressively over the first few runs. From tests carries out on new cables after manufacture and during research and development testing, we know that average cumulative values for permanent stretch for successive pulls on a new cable arc approximately as follows;

1st Pull	60%
2nd Pull	75%
3rd Pull	85%
4th - 8th Pull	Not measured
9th Pull	98%

It is evident that, if one corrects to the marks, the depth-measuring device is assuming that (he cable is fully stretched. However, since on the first two runs the cable has not fully stretched, the measuring device will show a reading that is too deep, and a negative correction must be made.

We therefore propose that engineers use the following adjustment, after making the correction given by the stretch charts:

1st Run	Subtract 40% of 0.21% (= - 0.0840%) of Cable Depth
2nd Run	Subtract 25% of 0.21% (= - 0.0525%) of Cable Depth
3rd Run	Subtract 15% of 0.21% (= -0.0315%) of Cable Depth
4th Run	Subtract 10% of 0.21% (= -0.0210%) of Cable Depth
5th Run	Subtract 5% of 0.21% (= - 0.0105%) of Cable Depth
6th & subsequent runs, use no further adjustment

If you require any additional information, please do not hesitate to contact us.

	Español\| Home \| Our Story \| Distributors \| News \| Contact Us \|
	\| Catalog \| Manual \| Features \| Designation \| Warranty \| Calculator


Camesa, Inc · 1615 Spur 529 · P.O. Box 1048 · Rosenberg, Texas 77471 Phone: (281) 342-4494 · Fax: (281) 342-0531