Recent studies i.ndicate that the overall cost of coring is influenced more by higher rig costs, due to additional trip time and slower penetration rates, than by charges made by the coring companies for their tools and services (Fig. 1). Because of this, a major R&D effort was initiated to d~velop tools to reduce those costs.In this paper three new tools are reviewed with emphasis on design, operational requirements and limitations, and field results.

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