HF260D borehole drilling rig in Guatemala
Drilling fluid is one of the most important stages of hydraulic drilling and needs to be understood by all drillers. Handling and control is relatively simple if a few simple rules are followed. We can have very complex and complex mud controls, but usually they are not necessary for well construction.
However, I cannot stress enough the importance of good mud control. It makes or breaks every well you drill. At this point we should mention that bentonite is difficult to mix and is best done with a jet hopper. Proper drilling fluid concept means that its viscosity should maintain the proper sealing effect while invading the aquifer as little as possible. This is developed by having the proper weight and viscosity.
Once we have the fluid ready to the recommended conditions it is circulated in the borehole and in doing so (the weight of the fluid is higher than the pressure of the formation) the fluid has a tendency to permeate outward into the formation itself. The sides form clay walls. In other words, the formation itself filters out the clay particles and forms what we call a filter cake. The thickness of this filter cake is determined by the ability of the filter cake to prevent water loss into the formation. If we maintain a relatively thin filter cake, water loss and formation contamination will be minimal, however, thick or deep permeate filter cakes are difficult to remove, limiting or preventing flow from the formation into our finished wells.
We can start drilling with a known fluid but one thing to always keep in mind is that when we drill through natural clay we mix the same fluid with ours and sometimes this contamination is very high . In order to maintain the type of fluids we can use to build the most efficient work, we must test our fluids for quality.
Contact: James Ye
Add: HEADQUARTERS ECONOMIC PARK, YUEQING,ZHEJIANG,CHINA