Expensive water acquisition and disposal

Globally, oilfield operations must pay high costs for water acquisition and produced water disposal. Municipal and state restrictions make fresh water difficult to obtain and therefore more costly.

Faced with these challenges, Occidental Petroleum Corporation (Oxy) in Bakersfield, California, sought a cost-effective method of preparing well treatment fluids using oil field–produced water. In this effort, several serious problems had to be addressed:

• Conventional fluid treatments were expensive, time-consuming, and energy-intensive.
• Polysaccharide-based well treatment fluids prepared with produced water showed poor fluid viscosity.
• Pretreatment with biocide, an additive that kills bacteria, did not resolve the problem.
• Adding additional biocide or changing fluid formulas did not work.

New fluid stabilizer additive compound

Schlumberger applied a simple, low-cost treatment for Oxy. A fluid stabilizer additive compound was developed that was added to produced water and mixed. In less than 10 minutes, the stabilizer-treated produced water was ready to use in well treatment fluid preparation. The resulting fluid did not suffer any of the fluid viscosity problems encountered with polysaccharides as guar, and it was capable of denaturing bacterial enzymes in produced water (the main cause of polysaccharide damage).

Cost savings for 33 wells

Using produced water for a 33-well campaign rather than custom formulations of fresh water and potassium chloride (KCl) saved Oxy a substantial amount of money. The company has since used the successful formulation in more than 100 jobs.