Auxiliary Cementing Equipment: The Supporting Tools You Need
A successful cement job needs more than just a cementing unit. You also need auxiliary cementing equipment — the supporting tools and equipment that make the job go smoothly. These are the smaller, specialized pieces of equipment that you don't think about until you need them, but they're essential for a good cement job. Let's break down the main types of auxiliary cementing equipment.
Bulk Cement Storage and Handling
Cementing uses a lot of cement powder — a typical well cementing job uses 50-500 tons of cement. You can't carry that on the cementing truck. You need bulk cement storage and handling equipment:
- Bulk cement silos: These are big vertical tanks that store cement powder on location. They come in different sizes — 20-ton, 50-ton, 100-ton silos. You need enough storage for the cement job, plus a buffer.
- Bulk cement trucks: These are trucks that carry cement powder in big silos. They deliver the cement to the well site, and they blow it pneumatically into the on-site silos.
- Screw conveyors and pneumatic conveyors: These move the cement powder from the silo to the cementing unit's mixing hopper.
Cementing Manifolds and Wellhead Equipment
You need equipment to connect the cementing unit to the wellhead, and to control the flow of fluids:
- Cementing manifold: This is the valve manifold that connects the cementing unit to the wellhead. It has valves for different lines, pressure gauges, and check valves. It lets you control the flow of cement and drilling fluid, and switch between different pumps.
- Cementing head: This attaches to the top of the casing, for pumping cement in and launching plugs.
- Plug launcher: This is where you load the cement plugs, and launch them down the casing.
Cement Evaluation Tools
After you cement the well, you need to check that the cement job was successful. You need cement evaluation tools:
- Cement bond log (CBL): This is a wireline log that measures the acoustic impedance between the casing and the cement. It tells you if the cement is bonded to the casing, and if there are any gaps.
- Variable density log (VDL): This is another acoustic log, that gives more detail about the cement bond. It's used together with the CBL to evaluate the cement job.
- Cement evaluation tools: These are the tools that you run down the well to take the measurements. They're part of the wireline logging equipment.
Other Auxiliary Equipment
There are lots of other smaller pieces of auxiliary cementing equipment:
- Casing centralizers: These are devices that attach to the casing, to keep it centered in the hole. Good centralization is essential for a good cement bond.
- Float collars and float shoes: These are check valves that go on the bottom of the casing. They let cement flow down, but not back up.
- Cement plugs: These are rubber plugs that separate the cement slurry from the drilling fluid, and push the cement down the casing.
- Cement baskets: These are used to support the cement slurry in weak formations, so it doesn't leak off into the formation.
FAQ
Q: Why is auxiliary cementing equipment important?
A: Because a cement job is only as good as all the parts. If you have a great cementing unit, but bad centralizers, or a bad manifold, or no way to evaluate the cement job, the cement job can still fail. Good auxiliary equipment is essential for a successful cement job.