Norton Christensen, Inc.

F James Thornton

Clifford R Pay

Coring samples can be taken in highly fractured rock formations without physical disturbance of the coring sample as it is cut and without jamming the core within the core barrel by using a rotating coring bit characterized by a pilot portion. The pilot portion extends the inner gage to form a longitudinally extending cylindrical surface. The nose of the pilot portion is characterized by a crowned surface wherein cylindrical polycrystalline diamond (PCD) cutting elements are axially disposed and longitudinally extending from the crowned surface. The width of the crowned surface which forms the nose of the pilot portion, is substantially less than the distance between the inner and outer gages of the coring bit. The pilot portion joins a flank portion of the bit through a cylindrical and longitudinally extending pilot gage. The length of the pilot gage is sufficiently long so that the cutting action provided at the nose of the pilot portion is substantially unaffected by the cutting action occurring at the flank portion of the bit.

Growing community of inventors

Bakersfield, CA, United States of America

F James Thornton