Patent ID: 8746372

Claim:
The method of providing a plurality of shearing drill collars used in the drilling of oil and gas wells, comprising: providing a first drill collar with a first drill collar outer sleeve comprising a first drill collar first material for carrying structural loads, providing said first drill collar with a first drill collar second material within said first drill collar outer sleeve which is lower in shear strength and is greater in unit weight than said first drill collar first material, and providing a hole in said first drill collar second material for the circulation of fluids, said first drill collar outer sleeve comprising a maximum wall thickness smaller than a maximum wall thickness of said first drill collar second material, further providing first drill collar threads on said first drill collar outer sleeve; providing a second drill collar with a second drill collar outer sleeve comprising a second drill collar first material for carrying structural loads, providing said second drill collar with a second drill collar second material within said second drill collar outer sleeve which is lower in shear strength and is greater in unit weight than said second drill collar first material, and providing a hole in said second drill collar second material for the circulation of fluids, said second drill collar outer sleeve comprising a maximum wall thickness smaller than a maximum wall thickness of said second drill collar second material, further providing second drill collar threads on said second drill collar outer sleeve; providing that said first drill collar threads on said first drill collar outer sleeve connect with said second drill collar threads on said second drill collar outer sleeve.