Reasons for Using Cementing Plugs

1
Reasons for Using Cementing Plugs

• Remove mud sheath
• Separate cement and Mud
• Prevent over displacement
• Surface indication
• Pressure test casing

2
Five Wiper Cementing Plugs

• Available with
• aluminum inserts
• plastic inserts
• non-rotating (NR) plastic inserts
• 350 psi rupture diaphragm in bottom plugs
• Surface release or sub-surface release (SSR)
• Compatible with water-based or oil-based muds

3
NR Cement Plug System

• Reduces drillout time
• PDC drillable
• 350 psi rupture diaphragm
• Use with NR float collar
• All plastic inserts

4
Top Bottom Plugs with NR Float Collar
5
NR Cement Plugs
6
Pumping Cement without Cement Plugs

• Much cement contamination
• No surface indication of cement placement

7
Pumping Cement with Top Plug Only

• Top plug wipes mud sheath from casing ID
• Separates cement from displacement fluid
• Surface indication when cement placement is
  complete
• Require additional shoe track length

8
Accumulated Mud Volume Ahead of Cement Plug

• Fill up per 1,000 ft. casing

9
Pumping Cement with Top Bottom Plugs

• Preferred method
• Bottom plug wipes mud sheath from casing ID
• Surface indication when cement placement is
  complete
• Maximum cement/mud separation

10
Polycrystalline Diamond Compact Bits (PDC)

• Soft medium formations
• Improves rate of penetrate (ROP)
• Longer service life

11
Concave PDC Bit
12
Illustrates aggressive nature of PDC bits