Changes

The difference between full-closure and other coring systems is that the core catcher is not exposed during coring. This allows the inner core barrel to slip over the soft core with a minimum of disturbance. After coring, a ball is pumped downhole activating the core catcher and sealing off the bottom of the barrel ([[:file:conventional-coring_fig3.png|Figure 3]]).

The difference between full-closure and other coring systems is that the core catcher is not exposed during coring. This allows the inner core barrel to slip over the soft core with a minimum of disturbance. After coring, a ball is pumped downhole activating the core catcher and sealing off the bottom of the barrel ([[:file:conventional-coring_fig3.png|Figure 3]]).

The hidden core catcher is both the major asset and major liability of this coring system. Since the core catcher is not exposed during coring, coming off bottom is likely to result in lost core. If the catcher is not activated after coring, the core will be lost during tripping. Against these risks, the benefits are a longer length and larger diameter core than is possible with a rubber sleeve core barrel and a less disturbed core than one cut with a conventional coring system.

The hidden core catcher is both the major asset and major liability of this coring system. Since the core catcher is not exposed during coring, coming off bottom is likely to result in lost core. If the catcher is not activated after coring, the core will be lost during [[trip]]ping. Against these risks, the benefits are a longer length and larger diameter core than is possible with a rubber sleeve core barrel and a less disturbed core than one cut with a conventional coring system.

===Rubber sleeve core barrel===

===Rubber sleeve core barrel===