**7. Field applications of high-performance WBMs**

In response to increasing environmental restrictions and economic concerns, there has been an upsurge in demand for water-based muds (WBMs) in the last 15 years, particularly for off-shore operations. Industry operators and service providers demanded Water-based muds to substitute the stable and inhibitive invert emulsion fluids. Some of the most common problems with WBM are hole washouts, poor hole cleaning, bit balling, tight holes, inappropriate reaming and stuck pipe, shakers screens blockage, reducing total solids control equipment (SCE) performance, logging difficulties, and running casing are all associated with the appropriate mud design [25].

Numerous fields have applied HPWBMs to overcome the encountered problems, including complex formation drilling, high-temperature drilling, borehole instability, and high collapse stress formations. In China, the complex formations containing mudstone, fine sandstone, mudstone intercalated with salt rock, and pure salt rock were successfully drilled using HPWBMs. The mud exhibited better clay inhibition, rheological and filtration characteristics, and rate of penetration and was environmentally safe [26].

#### *Utilization of Biopolymers in Water Based Drilling Muds DOI: http://dx.doi.org/10.5772/intechopen.105516*

A well having issues during drilling including borehole instability, risk of induced losses, and tight hole owing to the presence of unstable shale was successfully drilled using HPWBM. The well was drilled to total depth without any NPT attributable to drilling fluid or hole cleaning. A gauge hole was drilled with minor washouts. The cuttings were distinct, suggesting good inhibition. In comparison to the fluid applied in former wells, the proposed HPWBM system demonstrated its superiority and efficiency [3].

Similarly, in South China's deepwater well drilling operation, a high-efficiency mud system was determined to be acceptable, and the well application revealed that the selected mud is an excellent alternative to OBM or SBM [5]. HPWBM has been successfully deployed in different fields in Dubai, which contain higher reactive clays and have reached higher degrees of inclination [25].

A new HPWBM was designed to fill the gap between conventional WBM and emulsion-based mud systems in terms of drilling performance. The mud has been tested in the field with some of the most challenging onshore, deepwater, and continental shelf wells. These wells would otherwise have been drilled with oil or synthetic-based mud [27].

Scleroglucan as a mud additive has also been used during drilling of gas field exploration in various fields. The field experiments confirmed its salt and thermal stability and found a stable additive up to 80°C.
