Experimental study of hydrophilic additives on filter cake permeability and filtrate losses

In the past few years, great emphasis has been placed on developing the water-based mud system in drilling operations because its properties are suitable for the environment and it is a better choice than oil- and synthetic-based muds. Despite research and development in this field, water-based muds still have filtration issues that lead to drilling problems, and attempts must be continued in this regard. Therefore, this work aims to reduce the filtrate loss of water-based mud by affecting the drilling cake and making the permeability as low as possible with enhanced properties that resist the filtration of the drilling fluid. Special care was taken to develop suitable mud rheological properties in terms of plastic viscosity, yield point, and gel strength compared to API standards. To this end, some hydrophilic materials were added to the mud, such as thinners (spersene and trisodium phosphate TSP]) and some polymers (sodium silicate SS] and poly acryl amide PAA] (to compare with the basic mud. The results showed that using thinners and polymers without carboxymethyl cellulose (CMC) and baryte reduced filtrate loss and permeability by a small percentage. On the other hand, adding CMC and baryte to the four additives (spersene, TSP, SS, and PAA) each separately reduced the permeability by 66.1%, 67.7%, 74.1%, and 79%, and reduced filtrate loss by 50.1%, 51.4%, 55.3%, and 58.6%, respectively. It was concluded that adding PAA with CMC and baryte can effectively reduce filtrate losses due to its ability to provide a membrane of low permeability.