Chevron Corp. has come out swinging in its fight to continue drilling in the deep waters of the Gulf of Mexico, arguing that not all oil firms should be tarred with the brush of BP PLC's Deepwater Horizon disaster.

In an interview with The Wall Street Journal, Chevron chairman and CEO John Watson said he accepts the need for tighter drilling regulations in the wake of the spill, which since April has fouled the waters and coastline of the Gulf. But Mr. Watson, 52, called unnecessary the six-month moratorium on deep-water drilling...