Law360, New York (October 07, 2009) -- Auto-Dril Inc. has claimed that the automatic drilling systems patent asserted by rival National Oilwell Varco LP is unenforceable because during prosecution the purported inventor concealed key prior art that renders the patent invalid.
Midland, Texas-based Auto-Dril argued that National Oilwell's oil and gas exploration patent is invalid and unenforceable for a variety of reasons, including inequitable conduct and estoppel, in counterclaims and affirmative...
