The cost of water-based drilling fluid is lower, but it cannot be reused, and it is difficult to dispose of. Because the waste is basically not disposed of, normally land filled. Domestically, it mainly inherits the technology of the former Soviet Union, and most of them are water-based.
Oil-based drilling fluid is a development trend. Compared with the cost, the cost of a single well is relatively high, but the cost of drilling a large area of wells is lower because it can be reused. It has many advantages such as high temperature resistance, salt and calcium invasion resistance, good borehole wall stability, good lubricity and less damage to oil and gas layers. This product system has become an important means of drilling difficult high-temperature deep wells, highly deviated directional wells, horizontal wells and various complex formations, and can also be widely used as unblocking fluid, perforation completion fluid, work over fluid and Take heart fluid, etc. In some places, oil-based drilling fluid can only be used in the formation. For example, in a section of formation in Mexico, it hardens immediately when exposed to water, and the drill bit cannot move at all, so oil-based drilling fluid must be used.
However, water-based drilling fluids will not disappear. For example, when drilling the surface, water-based drilling fluids are used to save costs and speed up. When the lower complex formations are replaced with oil-based drilling fluids, it is best to do what we can.
