Improved/enhanced oil recovery (IOR/EOR) has the potential to unlock a significant amount of residual and trapped oil from existing and new hydrocarbon resources. This chapter addresses the various IOR/EOR strategies in carbonates and sandstone reservoirs, including chemical EOR, and hybrid EOR procedures. Each of these EOR approaches has its own set of challenges and preferences when it comes to the environment where it is used. Recent investigations have provided new insights into COBR systems, which have helped to improve the performance of these EOR methods. Detailed awareness of COBR systems can aid in better implement EOR methods in the field to maximize oil recovery (i.e., cost-effective) while also reducing environmental impact (i.e., CO2 footprint). Consequently, the primary goal of this chapter is to increase the reader's understanding of the extent of fluid-fluid and fluid-rock interactions to enable efficient IOR/EOR project designs that accurately reflect the requirements of candidate reservoirs for upstream oil and gas applications.
Sandstone formations are very complex in terms of mineralogy; it consists of a variety of minerals with different properties, minerals such as carbonate, clays, feldspars, iron oxides, and other minerals. This complex mineralogy will make it very difficult to have an ideal stimulation fluid; hence several stages and fluids are used. This chapter will cover the interactions of different fluids and additives with rock minerals utilizing experimental and simulation aspects. The basic chemistry of sandstone acidizing and the composition and additives of sandstone acidizing fluids are covered. This chapter will shed light on the compatibility between different fluid stages and the fluid in the same stage. Acidizing fluids such as HCl, HF, corrosion inhibitors, and clay stabilizers is discussed. Fluid/rock interactions that may cause fines migration, clay swelling, fluid retention, fluid adsorption, variations in porosity and permeability, and wettability alterations are analyzed.
Drilling fluids are designed to optimize the drilling performance and minimize the formation damage. Various compositions can be used to prepare the drilling fluids depending on the wellbore demands and environmental concerns. This chapter discusses the drilling fluid properties and their functions as well as the common additives used in the drilling operations. The recommended rheological range of different fluids is presented. In addition, the recent technologies for enhancing the drilling fluids' efficiency (such as using nanotechnology) are discussed. The impact of several additives on the compatibility of drilling and completion fluids is presented. Finally, the interactions of drilling and completion fluid solids with the formation rocks for conventional and unconventional reservoirs are presented. Enhancing the fluids' stability is a key factor in achieving successful drilling and completion operations. Using polymeric materials and nanoparticles as fluid additives can significantly improve the thermal stability, rheological, and filtration properties.
The environmental impacts of offshore oil and gas exploration, drilling, production, and operation are identified. The importance of controlling and managing emissions, discharges, and disposal to minimize impacts and consequences is emphasized. The impact of drilling and dredging activities on the marine environment is highlighted as one of the main threats to the marine ecosystem. The chapter emphasizes that risk management and business continuity are fundamental to avoid threatening project safety and investment development. The risk management approach as the roadmap to achieve regulatory compliance is emphasized. The key advantages of comprehensive HSE and risk management systems are summarized. The chapter explores the produced water and ballast water effluent quality and regulations requirements. The KPIs are presented with steps required to conduct further analysis in case of noncompliance. HSE aspects, impacts, mitigations, and compensation measures are presented, addressing concerns from exploration to production.
