API standards for rig inspections:

• API RP 4G: Outlines recommended practices and procedures for inspecting, maintaining, and repairing drilling and well-servicing structures (e.g., masts, derricks, and substructures).  

• API RP 8B: Defines procedures for the inspection, maintenance, and repair of hoisting equipment like traveling blocks, hooks, and elevators. 

• API RP 7G-2: Specifies the required inspection levels, procedures, and testing for used drill stem elements, including drill pipe bodies and tool joints. 

• API Spec 16A: Focuses on the design, manufacturing, and testing of well control equipment, including Blowout Preventers (BOPs).

​

Categorized Inspection Scopes

• API categorizes structural inspections into four levels, which increase in intensity, dismantling requirements, and frequency:

• Category I: Visual observation of equipment while in use by the rig crew to identify obvious defects.  

• Category II: More thorough visual inspection including cleaning, covering exposed areas, and checking specific non-destructive testing (NDT) areas. 

• Category III: Visual and NDT of critical load-bearing components. Requires partial dismantling to access hidden or high-stress areas.  

• Category IV: Complete disassembly of structures. Extensive NDT is conducted on all primary load paths to verify the absolute integrity of the rig.  ​