This chapter explores the multifaceted integrity challenges associated with water injection wells—critical components of secondary recovery operations aimed at maintaining reservoir pressure and enhancing hydrocarbon production. These wells must reliably inject large volumes of water over extended timeframes, often under high pressure and in chemically aggressive environments. The chapter outlines the key well designs and operational principles governing water injection, emphasizing the central role of injection water quality in sustaining well performance and structural integrity. The chapter first addresses the detrimental effects of poor water quality, highlighting mechanisms such as internal corrosion from oxygen, CO₂, and H₂S; microbiologically influenced corrosion (MIC) by sulfate-reducing bacteria; and inorganic scaling caused by mixing incompatible water chemistries or temperature/pressure shifts. These phenomena can significantly reduce injectivity, damage tubulars, and compromise zonal isolation. Effective mitigation strategies—such as water filtration, deaeration, biocide, and scale inhibitor treatments—are examined in detail. Injectivity and conformance are then analyzed from an integrity perspective. Plugging, casing corrosion, and poor zonal isolation can impair water sweep efficiency and result in out-of-zone injection, undermining reservoir management objectives. Monitoring techniques such as Production Logging Tools (PLT), Distributed Temperature Sensing (DTS), and acoustic diagnostics are presented as essential tools for detecting water flow paths and identifying integrity failures. A detailed geomechanical discussion follows, focused on pressure containment and casing stress evolution during high-pressure injection. The chapter presents evidence from numerical simulations and field data that excessive injection pressures, particularly near faults or in weak formations, can cause casing deformation, tensile failure, or loss of cement bond. Historical trends from major fields (e.g., Daqing and Pubei) are used to illustrate the correlation between injection pressure and casing failure incidence. Finally, the chapter examines long-term integrity management strategies for water injectors. These include cumulative corrosion assessment using periodic logging, fatigue evaluation under cyclic pressure conditions, and cement degradation from persistent chemical exposure. Integrity considerations during well abandonment (P&A) are discussed, highlighting the challenges of sealing altered zones and dealing with residual pressure build-up. By integrating chemical, mechanical, and operational factors, this chapter provides a comprehensive framework for safeguarding the integrity of water injection wells throughout their lifecycle. The insights presented are critical for optimizing injection performance, protecting subsurface environments, and ensuring regulatory compliance in mature field development.

Integrity Management for Water Injection Wells

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发表日期：

2026年

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Ahmed Alsubaih,
Kamy Sepehrnoori

摘要

This chapter explores the multifaceted integrity challenges associated with water injection wells—critical components of secondary recovery operations aimed at maintaining reservoir pressure and enhancing hydrocarbon production. These wells must reliably inject large volumes of water over extended timeframes, often under high pressure and in chemically aggressive environments. The chapter outlines the key well designs and operational principles governing water injection, emphasizing the central role of injection water quality in sustaining well performance and structural integrity. The chapter first addresses the detrimental effects of poor water quality, highlighting mechanisms such as internal corrosion from oxygen, CO₂, and H₂S; microbiologically influenced corrosion (MIC) by sulfate-reducing bacteria; and inorganic scaling caused by mixing incompatible water chemistries or temperature/pressure shifts. These phenomena can significantly reduce injectivity, damage tubulars, and compromise zonal isolation. Effective mitigation strategies—such as water filtration, deaeration, biocide, and scale inhibitor treatments—are examined in detail. Injectivity and conformance are then analyzed from an integrity perspective. Plugging, casing corrosion, and poor zonal isolation can impair water sweep efficiency and result in out-of-zone injection, undermining reservoir management objectives. Monitoring techniques such as Production Logging Tools (PLT), Distributed Temperature Sensing (DTS), and acoustic diagnostics are presented as essential tools for detecting water flow paths and identifying integrity failures. A detailed geomechanical discussion follows, focused on pressure containment and casing stress evolution during high-pressure injection. The chapter presents evidence from numerical simulations and field data that excessive injection pressures, particularly near faults or in weak formations, can cause casing deformation, tensile failure, or loss of cement bond. Historical trends from major fields (e.g., Daqing and Pubei) are used to illustrate the correlation between injection pressure and casing failure incidence. Finally, the chapter examines long-term integrity management strategies for water injectors. These include cumulative corrosion assessment using periodic logging, fatigue evaluation under cyclic pressure conditions, and cement degradation from persistent chemical exposure. Integrity considerations during well abandonment (P&A) are discussed, highlighting the challenges of sealing altered zones and dealing with residual pressure build-up. By integrating chemical, mechanical, and operational factors, this chapter provides a comprehensive framework for safeguarding the integrity of water injection wells throughout their lifecycle. The insights presented are critical for optimizing injection performance, protecting subsurface environments, and ensuring regulatory compliance in mature field development.