Successful drilling is the result of good choices made by the drilling contractors. Experienced drilling contractor know there are a variety of drilling sites. This means making correct decisions about equipment, drilling fluid and fluid management in order have the job run smoothly. What are some of those decisions that contractors face? Let’s take a look at the ones that can have a major effect on the job and how drillers can mitigate the risks of a tricky site.
The first thing the drilling contractor is going to need to know is where the well is going to be drilled and what the dimensions of the well are going to be. Along with that, they will need to know the primary use of the well. All of these factors will dictate the correct drilling equipment for the site.
Having resources on hand to assist the contractor with information can be helpful. Any geological studies of the area or experts on the geological makeup will provide the drillers with vital information about the makeup of what they are drilling into. Any well logs from nearby wells, as well as other well owners in the area might also have information that could be used by the contractors. Finally, it might just come down to trusting your drilling contractor’s own personal experience. Sometimes their gut will tell them just what they need to know to select the right equipment.
Drilling Equipment Selection
Once the background info on the area has been obtained it is time to select the equipment. While a detailed description of what type of equipment is used in what situations is a bit lengthy for this article, here are a few of the different types of drilling rigs that your contractor might select:
- Reverse Circulation
- Cable Tool
- Air or Foam Drills
- Mud Rotary
- Driven Casing
The Drilling Fluid
Once the equipment has been selected it is now time to select the fluid that is going to be used for the site. There are quite a few options that are available for your contractor, but they all need to be able to do the same things:
- Suspend the drilled cuttings in the fluid during the drilling
- Bring those cuttings back to the surface and drop them off
One of the things that can greatly affect the drilling fluid is the pH factor of the water for the mix. The higher the pH the more the fluid behaves like a base (for those that have forgotten high school chemistry class). Drillers want the water to be in the range of 8 or 9 in order to prevent the drilling fluid from becoming too difficult to mix with the bentonite or polymer that they may be using. This means having to use more bentonite or polymer and raising the costs of the slurry.
Methods like using soda ash to bring up the pH of the water can help drillers save considerable dollars when mixing the drilling slurry. It can also help to prevent equipment wear, as slurrys with a more acid pH (below 7) can actually work to eat away at the metals used in the equipment
The Mixology of Drilling Fluids
Knowing the right additives to mix in with your drilling fluid can help to improve its performance. Bentoninte is actually composed of many small particles that need to be separated fully in order to hydrate it properly. Additives can help that. If your contractor is not aware of the proper mixing methods, it can reduce the efficiency of the drilling fluid and increase costs.
These are just a few of the decisions drilling contractors are going to face on site. Knowing the proper ways of addressing these site specific variables can affect the outcome and costs of your drilling!