Ethoxylated lauryl alcohol mixture applied as drilling fluid for filter cake removal: experimental design and formulation optimization

Wash mattresses play a crucial role in the petroleum industry, serving to remove filter cake accumulated on well walls. The use of oil-based fluids necessitates special fluids capable of ensuring complete filter cake removal to achieve effective cementation. This study aimed to develop a sustainable wash mattress formulated with minimal surfactant proportions. Its performance was evaluated across various temperature ranges, simulating thermal conditions within oil wells. A central composite experimental design was implemented to identify the solution with the best performance. The new cleaning system was characterized by rheology and surface tension measurements. It was tested for removal efficiency, wettability, and fluid compatibility within the studied temperature range. The selected formulation completely removed the filter cake in 523.8 s, exhibited Newtonian behavior, and showed surface tension values between 34.25 +/- 0.02 and 43.34 +/- 0.01 mN/m. Additionally, it maintained the rock's water wettability and was compatible with cement slurry within the 30-65 degrees C temperature range. These attributes make it an environmentally friendly and effective solution for its intended purpose.