The Offset Drilling Workshop was convened by the Science Operator and took place at ODP-TAMU on 13-14 September 1994. The objective of the workshop was to bring together scientific, engineering and drilling operations participants of ODP Legs 147 and 153 and some members of relevant JOIDES panels in order to discuss the problems encountered on these two legs and to make suggestions for progress of PCOM's offset drilling strategy.

Legs 147 and 153 were ambitious legs in difficult-to-drill environments. Neither leg progressed as planned, although considerable quantities of core of great scientific interest were recovered. Major deficiencies were revealed in all stages of the execution of these legs: the site surveys did not adequately describe the sites to be drilled, many items of drilling equipment were unable to cope with the hostile conditions encountered, and there were communication problems between the scientific proponents and ODP-TAMU personnel. All aspects are discussed in detail in this report and, where possible, specific recommendations have been made.

To ensure the future progress of offset drilling, two strategies are proposed:

(1) ODP needs to learn how to drill in difficult places. The logical outcome of this strategy is that an engineering leg is needed to test new equipment and techniques for establishing re-entry holes and coring in environments such as those encountered on Legs 147 and 153. The objectives of the engineering leg are defined.

(2) ODP needs to learn how to find easy places to drill. This could be achieved in two different ways. A drilling leg of shallow single bit holes might find a "sweet spot" for deeper drilling, in the manner that Hole 735B was found and successfully drilled on Leg 118. The site selection process in hard rock areas is not yet so precise that serendipity does not play a part. Alternatively, on a longer timescale, near or on-bottom geophysical measurements might be used to define spots where the drilling is easier. The relationship of geophysical properties to drillability is discussed.

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