posted by the Epiroc Exploration & OreBody Solutions team
May 30, 2017
Drill rods are a hugely important part of your drilling equipment and how you take care of your drill rods can have a major impact on your drilling performance. The regular use of drilling lubricants and thread compound is imperative for breaking in and maintaining a healthy drill string and helps avoid many problems. Here are a few reasons you need to use thread compounds and lubricants, and the purpose of each.
Prevent rods from cracking
Excessive vibration can cause drill rods to crack. Rod grease can help reduce in-hole vibration and extend the life of your drill string.
Prevent leaking rods
A good quality thread compound will help protect the metal surfaces of the threads and provide a good seal to prevent leaks. Little or no lubrication of the drill rods can cause more vibration and increased torque which in turn increases wear and tear of the rods. Drill rod threads that are worn, cracked or otherwise damaged prematurely will eventually leak.
Prevent rods from galling
High torque or loading without proper thread compound can cause galling of the drilling rod threads. This can also occur when there is dirt and dust on the threads, when the wrong kind of thread lubricant is used or when not enough of it is used. Grease is not thread compound. A quality thread compound must have a percentage of soft metal in it such as zinc, lead or copper. This provides protection of the two mating metal surfaces.
Prevent rods from belling
When a drill rod begins to “bell” it can have severe implications on the bore hole. Causes of this problem include over torqueing, over-tightening and excessive vibration in a dry hole. Lubricating the rods with good quality rod grease or a good mud program will help reduce these conditions.
Increase resistance to rust and corrosion
High quality lubricants are highly water repellant so they are resistant to water washout. Applied properly, the lubricant will adhere and protect the rods. A cutting oil such as Torqueless helps keep the rods and bit lubricated and extends the life of all steel parts including rods, casing, wireline etc.
As you look at the points above, you see that the use of compounds and lubricants will help lower wear and tear on drill rods and their threads. The use of a good thread compound with at least 50% zinc particle content, such as PIPE DOPE Z50, is recommended for the entire life of the rod and casing. Longer life for your drill rods leads to lower operational costs and better drilling performance. Proper maintenance can also have a positive impact on penetration rates and extend core bit life.
