Wouldn’t it be great if no matter where your drilling project was located, you always had access to fresh water? Sadly, we all know that is not the case and oftentimes we find ourselves having to drill using mine water, salty water, or water with all kinds of minerals and deposits. The problem with this kind of water is that using any kinds of polymers becomes really difficult.
The issue is in mixing the water with drilling fluid additives that can help you with difficult ground conditions is that you cannot get the right viscosity and the products lumps together producing “fish eyes”. For additives to work well, you need to mix well to produce the “chains” needed to be effective. Plus, it could take a lot more product and even then you won’t achieve the right viscosity.
We recently visited a site where the water consumption used in the drilling project came from a reservoir where the water was super saturated with sodium, calcium, and chlorine. The water was also 25% heavier than fresh water and loaded with manganese giving it a black colour. The team was having difficulty getting the drilling fluid additives to mix properly – the additives kept separating and decanting down to the bottom of the tank.
The drilling team had been using additives in an attempt to get through areas with sand and clay. Core recovery was very limited- at times zero, and the inner tubes were often trapped by the sand and clay. The very fine sand combined with the clay also caused blockages in the waterways of the bit. A lot of time was being spent on dealing with these equipment issues.
The team had been preparing a mixture of additives in fresh water that was then mixed with the salt water but this solution required a lot of additives. The new solution proposed by our field technician was to prepare a “viscosity pill” in a drum using pH adjusted fresh water. Make sure you add soda ash to control the pH levels, when needed, ideally to be between 7 and 10. You can test the water levels easily using pH strips. Then add the viscosity pill which is a mixture of DD-2000, Torqueless, Sand Drill, DD-955, prepare it in a drum with fresh clean water and pump it directly to the well to cause a pill effect.
Once the pill is injected, drilling continues using salt water. The time it takes for the salt water to dilute the pill allowed the team to drill 1.5 meters (the length of an inner tube) without any problems in the well. The technique required very little freshwater that could affect the quality of the well walls.
End result was that core recovery improved by up to 80% the time spent dealing with equipment issues was reduced by 50%, which meant more time (up to 2-3 hours per shift) could be spent drilling.
This visit was a great example of finding solutions the different issues that arise when you are dealing with diverse drilling conditions in ground and water. Drilling fluid additives are great solutions to these issues but there are many ways they can be used. Our technical team has come up with innovative ways to use them, so don’t hesitate to contact us for advice.