(41) Protecting Flow Assurance and Maximizing Injectivity in the Midstream Water Space

In the last 10-15 years, the US has seen a remarkable surge in the production of oil and natural gas as the industry learned how to properly complete and produce previously non-productive formations. With this increased hydrocarbon production, we have also seen an increase in the amount of water that is produced and must be managed. The large volumes of water that must be gathered, managed and eventually disposed, along with a growing trend for operators to prioritize their capital spend on drilling and completing revenue-producing wells, has created an opening for midstream water companies dedicated to produced water. While some of this produced water is treated to some degree and then used in ongoing completions to offset an equal volume of fresh water, the majority of it is destined for disposal via Class II UIC wells. Often this produce water has some degree of mineral scale over-saturation, or may be mixed with other waters that may or may not be compatible from a mineral standpoint. The water may contain various quantities of dispersed hydrocarbons, suspended organic material or inorganic solids such as iron sulfide or iron oxide - all of which can potentially impair the ability of the injection well to take water. Last, but not least, bacteria such as acid producing bacteria or sulfate reducing bacteria may be present in the produced water and may cause corrosion issues when allowed to contact bare steel and can generate biomass that again can impair injectivity. This paper will discuss the potential issues with the movement and injection of produced water outlined above. It will also outline and detail the best methods to monitor and analyze for these potential issues, the best approach to correcting or preventing of issues that may impair flow or injectivity and, finally, how to best monitor long-term to document success and properly optimize the preventative treatment program.