Cutting element, drill bit, system and method for drilling soft plastic formations

A drill bit for drilling subterranean formations, comprising:

• a bit body;
• at least one cutting element secured to said bit body, said at least one cutting element comprising:
• a cutting face comprising a superabrasive mass extending in two dimensions, said cutting face including at least a portion exhibiting a surface of sufficient smoothness to substantially overcome a tendency of formation cuttings to adhere thereto;
• and
• a sharp cutting edge at an outer periphery of said cutting face portion, said cutting edge defined by at least one radius of no more than about 0.005 inch or at least one chamfer having a radial width of no more than about 0.005 inch, said cutting edge lying between said cutting face portion and a side of said superabrasive mass.

A drill bit for drilling subterranean formations, comprising:

• a bit body;
• at least one cutting element secured to said bit body, said at least one cutting element comprising:
• a cutting face comprising a superabrasive mass extending in two dimensions, said cutting face including at least a portion exhibiting a surface with a sufficiently low coefficient of friction to substantially overcome a tendency of formation cuttings to adhere thereto;
• and
• a sharp cutting edge at an outer periphery of said cutting face portion, said cutting edge defined by at least one radius of no more than about 0.005 inch or at least one chamfer having a radial width of no more than about 0.005 inch, said cutting edge lying between said cutting face portion and a side of said superabrasive mass.

A system for drilling a soft, plastic subterranean formation exhibiting formation cuttings instability, comprising:

• a drill bit, comprising:
• a bit body;
• at least one cutting element secured to said bit body, said at least one cutting element comprising:
• a cutting face comprising a superabrasive mass extending in two dimensions ;
• and
• a sharp cutting edge at an outer periphery of said cutting face, said cutting edge defined between said cutting face and a side of said superabrasive mass;
• and
• a drilling fluid including a constituent for rendering clays present in said subterranean formation less susceptible to agglomeration for maintaining physical integrity of cuttings cut from said subterranean formation.

A method for drilling a soft, plastic subterranean formation, comprising:

• disposing a drill bit in a well bore adjacent said formation;
• rotating said drill bit and applying WOB to cause said drill bit to engage said formation;
• cutting discrete, elongated cuttings of formation material with cutting elements mounted on said drill bit;
• maintaining physical integrity of the cuttings while said cuttings are in proximity to said bit by introducing a clay-stabilizing additive-enhanced drilling fluid into contact therewith;
• and
• clearing said cuttings from said drill bit with said drilling fluid to a position thereabove in said well bore.

A drill bit for drilling subterranean formations, comprising:

• a bit body;
• a first plurality of superabrasive cutting elements having chamfered cutting edges and mounted to said bit body;
• and
• a second plurality of superabrasive cutting elements having sharp cutting edges and mounted to said bit body.