Changes

===Dipmeter and borehole televiewer===

===Dipmeter and borehole televiewer===

Dipmeters and borehole televiewers must detect formation contrast to be effective orientation tools. Formations that have apparent bedding dips at right angles or parallel to the core axis and limited changes in bedding attitude over the length of the core may not be appropriate for orientation by dipmeter or televiewer. If fractures are absent or abundant, or only at right angles to the core axis, results may also be unusable for orientation. Studies by Hocker et al.<ref name=pt03r23>Hocker, C., Eastwood, K. M., Herweijer, J. G., Adams, J. T., 1990, Use of dipmeter data in clastic sedimentological studies: AAPG Bulletin, v. 74, n. 2, p. 105–118.</ref> offer some indication of the limits of resolution possible using one contemporary dipmeter tool.

Dipmeters and borehole televiewers must detect formation contrast to be effective orientation tools. Formations that have apparent bedding dips at right angles or parallel to the core axis and limited changes in bedding attitude over the length of the core may not be appropriate for orientation by dipmeter or televiewer. If fractures are absent or abundant, or only at right angles to the core axis, results may also be unusable for orientation. Studies by Hocker et al.<ref name=pt03r23>Hocker, C., Eastwood, K. M., Herweijer, J. G., Adams, J. T., 1990, [http://archives.datapages.com/data/bulletns/1990-91/data/pg/0074/0002/0000/0105.htm Use of dipmeter data in clastic sedimentological studies]: AAPG Bulletin, v. 74, n. 2, p. 105–118.</ref> offer some indication of the limits of resolution possible using one contemporary dipmeter tool.

===Mechanical core orientation===

===Mechanical core orientation===