Applications and functions of HEC in Oil drilling
Drilling fluids with HEC are usually used in hard rock drilling and drilling in special situations such as circulating water loss control, excessive water loss, abnormal pressure, and uneven shale formations. The application effect is also very good in the drilling and large hole drilling process.
The fluid loss performance of the mud can also be greatly improved after the use of HEC. Greatly improve the stability of mud. HEC can be used as an additive to non-dispersed brine bentonite slurries to reduce water loss and increase viscosity without increasing gel strength.
In fracturing fluid, HEC can increase viscosity, and HEC itself has no effect on the oil layer, will not block fractures, and can fracturing oil wells. It also has the general characteristics of water-based fracturing fluids, such as strong sand suspension ability and low friction. The 0.1-2% water-alcohol mixture of potassium, sodium, lead and other periodic salts thickened by HEC was injected into the oil well with high pressure, fracturing, and the fluidity was restored within 48 hours.
The low-solid completion fluid formulated with HEC can prevent soil particles from blocking the oil layer gaps when approaching the oil layer. The water loss reduction properties also prevent a large amount of water from entering the oil layer from the mud to ensure the production capacity of the oil layer.
HEC reduces the friction of the mud, which reduces pump pressure and reduces power consumption. Its excellent salt-dissolving performance also ensures that no precipitation occurs when acidizing oil wells.
HEC can coexist stably with commonly used oilfield chemical additives such as pesticides, oxygen scavengers, mud water loss control agents and defoamer.