Chapter Fourteen - Special Focus on Produced Water in Oil and Gas Fields: Origin, Management, and Reinjection Practice

Abstract

This chapter comprehensively discusses produced water in oil and gas fields. The origin, the characteristic, and the production of produced water are considered to facilitate the understanding of its physics, chemistry, affecting factors, and corresponding impacts. The major produced water management methods, including produced water minimization, produced water reuse/recycling, and produced water disposal, as well as legal frameworks, policies, and regulations related to produced water from onshore and offshore oil and gas fields, are described. Commonly applied produced water treatment technologies in the oil and gas industry, corresponding technical details, and advantages and disadvantages are evaluated. Produced water reinjection (PWRI) is an important method to treat produced water, but the reservoir formations can be severely damaged during such reinjection process if the process is not fully understood and adequately managed. Formation damage caused by PWRI, its physics, mathematical models, and case studies are described in detail. Based on the analysis and evaluations in this chapter, it is concluded that produced water in oil and gas fields plays an increasingly important role in affecting profit margins for oil and gas exploration and production activities, thus operators need to consider and examine it carefully. Produced water issues can be effectively mitigated by various produced water treatment technologies under certain legal frameworks, policies, and regulations. Reductions in permeability and injectivity during PWRI can be accurately and effectively predicted and simulated by established mathematical models, verified by experiment and field data from several studies; a higher PWRI efficiency can be achieved with appropriate produced water treatments before the reinjection process.