Formation cutting method and system

A method of drilling a subterranean formation using a drilling rig, a drill string, a fluid pump located substantially at the drilling rig, a drilling fluid and plurality of solid material impactors, the drill string including a feed end located substantially near the drilling rig and a bit end including a drilling bit supported thereon, the method comprising:

• providing the drilling bit with at least one nozzle such that a velocity of the drilling fluid while exiting the drilling bit is substantially greater than a velocity of the drilling fluid while passing through a nominal diameter flow path in the bit end of the drill string;
• introducing the plurality of solid material impactors into the drilling fluid to circulate the plurality of solid material impactors with the drilling fluid through the drilling bit, the drilling fluid being pumped at at least one of a selected circulation rate and a selected pump pressure, a substantial portion by weight of the plurality of solid material impactors each having a mean diameter in excess of 0.100 inches;
• rotating the drilling bit while engaging the formation to generate formation cuttings;
• and
• circulating at least some of the drilling fluid, the plurality of solid material impactors and the formation cuttings away from the at least one nozzle.

A method of drilling a subterranean well through a subterranean formation using a drilling rig, a drill string, a fluid pump located substantially at the drilling rig and a drilling fluid, the drill string including an upper end located substantially near the drilling rig and a bit end including a drill bit supported thereon, the method comprising:

• providing the drill bit with at least one nozzle such that a velocity of the drilling fluid while exiting the drill bit is substantially greater than a velocity of the drilling fluid while passing through a nominal diameter flow path in the bit end of the drill string;
• providing a plurality of solid material impactors substantially adjacent the drilling rig;
• introducing the plurality of solid material impactors into the drilling fluid to circulate the plurality of solid material impactors with the drilling fluid through the drill string and through the drill bit, the drilling fluid being pumped at at least one of a selected circulation rate and a selected pump pressure, a majority by weight of the plurality of solid material impactors, a majority by weight of the plurality of solid material impactors having a mean diameter in excess of 0.100 inches;
• rotating the drill bit while engaging the formation to generate formation cuttings;
• and
• circulating at least some of the drilling fluid, the plurality of solid material impactors and the formation cuttings from the at least one nozzle.

A method of drilling a subterranean formation using a drilling rig, a drill string, a fluid pump substantially at the drilling rig and a drilling fluid, the drill string including a feed end located substantially near the drilling rig and a bit end including a drilling bit supported thereon, the method comprising:

• providing the drilling bit to include at least one nozzle such that a velocity of the drilling fluid while exiting the drilling bit is substantially greater than a velocity of the drilling fluid while passing through a nominal diameter flow path in the bit end of the drill string;
• providing a plurality of solid material impactors substantially adjacent the drilling rig;
• introducing the plurality of solid material impactors into the drilling fluid to circulate the plurality of solid material impactors with the drilling fluid at at least one of a selected circulation rate and a selected pump pressure through the drilling bit, a substantial portion by weight of the plurality of solid material impactors creating a structurally altered zone in the formation having a structurally altered zone height in a direction perpendicular to a plane of impaction at least two times a mean particle diameter of particles in the formation impacted by the plurality of solid material impactors;
• rotating the drilling bit while engaging the formation to generate formation cuttings;
• and
• circulating at least some of the drilling fluid, the plurality of solid material impactors and the formation cuttings away from the at least one nozzle.

A system for drilling a subterranean formation using a drilling rig, a drilling fluid pumped into a well bore by a fluid pump located at the drilling rig, a drill string including a feed end located substantially near the drilling rig, a bit end for supporting a drill bit, and including at least one through bore to conduct the drilling fluid between the drilling rig and the drill bit, the drill bit including at least one nozzle at least partially housed in the drill bit such that a velocity of the drilling fluid while passing through a nominal diameter of the through bore in the bit end of the drill string, the system comprising:

• an impactor introducer to introduce a plurality of solid material impactors into the drilling fluid and into the feed end of the drill string before circulating the plurality of impactors and the drilling fluid to the drill bit;
• the plurality of solid material impactors passing with the drilling fluid through the at least one nozzle in the drill bit such that the velocity of the impactors while exiting the at least one nozzle is substantially greater than a velocity of the drilling fluid while passing through the nominal diameter of the through bore in the bit end of the drill string, such that at least some of the plurality of impactors are circulated substantially back to the drilling rig with the drilling fluid, and wherein a majority by weight of the plurality of solid material impactors have an impactor diameter in excess of 0.100 inches.