Obtaining a stable olefin-based drilling fluid using non-treated produced water

Abstract

Produced water is the main waste stream in the oil and gas sector, with significantly greater concentrations of hydrocarbons, heavy metals, and other contaminants. Several works and technologies were developed to reuse the produced water in many applications including drilling and completion fluids. However, in general, a pretreatment is required. According to our knowledge, the reuse of produced water in non-aqueous drilling is still not reported. Therefore, this work proposed the formulation of olefin-based drilling fluids containing between 20-40% of untreated produced water. Through factorial experimental design, the influence of produced water, emulsifier, and viscosifier on the properties of the formulated emulsions was investigated. Our results show that produced water without treatment can be used as an aqueous phase for olefin-based drilling fluids, with the best formulation being the test that has R_O/A = 60/40, emulsifier concentration of 14.26 kg/m³ and viscosifier concentration of 2.85 kg/m³. The well-cleaning properties of the proposed formulation were evaluated through numerical simulation in a well with high inclination. The results showed that the hole cleaning was not affected by using untreated produced water in the fluid formulation. The results presented here open a new possibility to reuse produced water in drilling operations without performance loss.

Graphical Abstract

Keywords:

• Produced water
• drilling fluid
• inverse emulsion
• olefin
• and sustainability

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors would like to thank the Federal University of Rio Grande do Norte (UFRN), particularly the Laboratory of Surfactant Technology (LTT/Chemistry Institute/UFRN) and CAPES, for the financial assistance received for the realization of the research.