posted by Rod McCoremick, Blog author, Fordia Powered by Epiroc
July 5, 2020
As we say often in the blog, choosing the right equipment is one of the most important parts of the drilling process. Whether it’s choosing the right core bit, a reaming shell or some other part, there are always many factors to consider before making a choice. When it comes to overshots, there are regular overshots and safety overshots. Let’s look at four good reasons to consider a safety overshot.
Safety, safety, safety
Safety on drilling sites has always been an issue and any product that can increase the level of safety for a driller is a good thing. Let’s face it, when you are hoisting heavy objects full of rock into the air, safety should be on your mind. With many overshots, as they are coming up out of the hole, you may have to manipulate the locks by twisting or engaging other moving parts, in order to manually lock the overshot head. Luckily, some overshots come with automatic safety locks. The Excore EX ll is an example of a safety overshot that has a safety mechanism that is automatically engaged without a drilling helper having to do anything. This translates into better efficiency as no time is lost doing it manually. The Excore EX ll overshot is patented and is independently tested for its lifting capacity, so you can use it with confidence.
You can reduce risk even more by having a secondary locking pin that is independent. This provides one more way of locking the inner tube. This becomes really important in case the spearhead or the lifting dogs are worn out and need to be replaced. The Excore EX ll has this secondary locking pin.
Less human error
When a drill crew is rushing to get core in the box, it is easy to forget to do every step of a process, no matter how often you’ve done them before. Forgetting to lock the safety mechanism on the overshot head can have pretty disastrous results. A safety mechanism that is automatically engaged protects drillers form an accidental release of the inner tube assembly.
Overshots with a twist lock assembly have a lot more parts and those parts need to be maintained. While you are maintaining or cleaning those small parts, they can be dropped or lost. Nobody has time to waste looking for them or for a replacement part. Fewer parts is an advantage all the way around.
Easy to use
The Excore EX ll overshot, for example, has a release mechanism of the inner tube assembly that is pretty intuitive. Training your drill crew on how to use and maintain it is quick and easy. When the inner tube assembly is on the floor, the way you release the inner tube assembly is really similar to that of a standard, non-locking overshot. You get a special release tool with every overshot. When the inner tube is in the rod string, the tool makes releasing the inner tube assembly safe and easy.
Safety features are always being added to drilling equipment as the industry identifies areas where improvement is needed. It’s important to keep up and know which products that have found new, safer ways to do the job. Our technical team is always available to discuss and guide you when choosing equipment, whether it’s safety overshots or drill bits. Reach out to them for advice on choosing equipment or any other technical question.