Jitendra Sangwai

Hydrocarbon derived from tight shale and other low-permeable reservoirs is an important and rapidly expanding front in energy development. Untapped hydrocarbon reserves can be exploited by fracturing these rocks using pressure-fracturing fluid. Different forms of fracturing fluids have been created, employed, and tested in fields for their efficiency and applicability. Aqueous polymer-based fracturing fluids and acid fracturing fluids are the most prominent class of field-employed fracturing fluids. Hydraulic fracturing procedures leave chemically complex fluids in the shale formation for at least 2 weeks. This gives the hydraulic fracturing fluid (HFF) plenty of chances to react with the formation at reservoir temperature and pressure. The interaction of fracturing fluid with the reservoir rocks and formation fluids has been discussed in this chapter. Furthermore, reaction kinetics, formation damage, and classes and mechanics of fracturing techniques have been elaborated.

The relevance of nanotechnology in the field of energy resources has been growing at a swift pace. The term ‘catalyst’ has a whole new outlook since the foundation of nanomaterials in process industries. Nanocatalysts, in general, play a vital role in the improvement of resource handling and process efficiency. New prospects to achieve sustainable processing have been made possible through the progress in nanotechnology. These developments of nanomaterials in the energy sector have also reached the parts of the oil and gas industry. In downstream processing of oil and gases, the use of nanocatalysts is commonplace. As the focus towards the production of heavy crude oil has seen an uprising, the use of nanomaterials has shown a promising scope in altering heavy oil properties to favour the oil recovery mechanisms. The majority of the reservoirs around the world have volumes of heavy crude oil with only a few effective ways to produce it. With the ever-growing energy demands it is of due importance that the focus has been shifted to implement nanotechnology in heavy oil production. This chapter discusses the role of nanomaterials in the development of heavy oil recovery. Different types of mechanisms that explain the effects of nanoparticles and their interaction with oil and its constituents are highlighted. The effects coupled with the use of various thermal treatment schemes have been explained. The scope of applicability in the field of flow assurance has been discussed. The use of nanoparticles in improving the existing EOR applications and devising new ways to achieve the production of heavy fractions.

Heavy oil reservoirs are one of the largest remaining crude oil reserves in the world. Often, the inherent properties of heavy and extra-heavy oils cause major problems in production and transportation processes. The viscosity of these oils makes their treatment difficult with conventional means. Use of solvents to dissolve the heavy oils has been a traditional method to deal with these problems. Improvement in flow through solvent treatment can be further optimized through the use of nanoparticles. Literature works have suggested that nanoparticles have catalyzing effects which affect the polar species of heavy oils. This study is aimed at examining the effects of metallic nanoparticles in altering the viscous property of heavy fraction. Use of thermal stimulation in association with solvents are explored as a means to achieve viscosity reduction. These applications can be further extended into the areas of flow assurance.

An ultra-low IFT (interfacial tension) is required between the liquid–liquid systems to dislodge the crude oil completely from the pores of the formation. As a huge amount of alkali is used for this purpose, scale formation and formation damage near wellbore region is a common issue. To perform an economically and environmentally viable process, it is obligatory to design the process with low and optimum concentration of alkali. Moreover, if the concentration of alkali is properly designed according to the oil chemistry, the alkali flooding alone could result in a favorable recovery for high acid number crude oil. So, the present study utilized low concentration of NaOH, to understand the behavior of alkali at the IFT of hydrocarbon–water system. Hydrocarbons like heptane and benzene were selected to understand the influence of hydrocarbon type on the IFT reduction. It was found that the IFT between the hydrocarbon–water system continuously decreases with an increase in NaOH concentration; moreover, a minimum concentration of 100 ppm is required to initiate reduction reaction. It is evident to state that IFT is dependent upon type of the hydrocarbon, because the enhanced reduction is observed in aromatics–water system using NaOH due to stronger cation-π interaction.

Nanotechnology is a common word used by academia which is referred to the applied nanoscience conducted at nanoscale (1–100 nm) for variety of industrial applications. Application of nanotechnology in various fields is increasing extensively resulting in an enormous amount of publications in the distinct field. Nanoparticles (NPs) possess unique properties due to their larger surface area which leads to prolong application in multifold. Researchers working in enhanced oil recovery (EOR) areas are trying to get rid of challenges faced by the oil and gas companies for crude oil production. This chapter, therefore, focuses on work carried out by the researchers on chemical and rarely on thermal, gas injection, and biological EOR methods using NPs. Chemical enhanced oil is recovery (CEOR) methods taken into consideration due to their popularity in oilfields than the other existing methods. Viscosity, interfacial tension (IFT), and wettability are the major influencing factors for EOR. The authors intend to make the reader understand the pore-scale mechanism behind the enhanced oil recovery in the presence of NPs. In the early stage of enhanced oil recovery, it is essential to understand the properties of various NPs. Literature review reveals that properties of NPs mostly depend on methods they are prepared. Hence, at the beginning of the chapter, the types of NPs, preparation, and their characterization are explained briefly with the application of various nanoparticles in CEOR. Limitation of NPs application in chemical EOR area is spelled out clearly with the recommendation at the end.

Owing to the extinction of conventional reservoirs, it is imperative for engineers to find the unconventional oil and gas resources. Drilling an unconventional field requires engineered drilling fluids because an efficient drilling operation purely depends upon the performance of drilling fluid. Drilling fluid which is a combination of solids and fluids performs many functions, such as cooling the drill bit, cleaning the wellbore, maintaining the wellbore pressure and development of a filter cake to prevent the invasion of fluid into the formation. The drilling fluid can be classified into oil-based mud (OBM), water-based mud (WBM) and pneumatic fluid (or) air-based fluid. Conventional drilling fluids which are in use lose their efficacy during drilling a complex reservoir, like high temperature high pressure (HTHP) and highly saline reservoir. Nanomaterials which are unique due to their distinctive properties, like high surface to volume ratio, thermal stability and conductivity, found their application in almost all fields of engineering. Many studies have been conducted to analyse the enhancement of drilling fluids through the application of nanoparticles. The studies resulted in enhancement in rheological, filtration, thermal properties of the drilling mud and also improved the wellbore stability. This chapter elaborately discusses about how the application of various types of nanoparticles/nanocomposites helps to enhance the rheological and filtration properties of the drilling mud.

The measurement of the rheological properties of gas hydrate slurries necessitates the high pressure rheometer that can provide a proper mixing inside the pressure cell during hydrate formation from two multiphase fluids, water and gas. However, the hydrate formation is highly challenging in conventional cup and bob geometry due to its plane surface. To overcome this, the present work focuses on the study of high pressure rheology for hydrate slurries formed from water-heptane (C7H16) system using a high pressure cell in Anton-Paar® (MCR-52) rheometer and a modified Couette geometry which enables the measurement of rheological studies of multiphase hydrate system. It was observed that the hydrate slurries exhibit shear thinning behavior. The present study provides an important information about the rheology of methane hydrate slurries formed from multiphase systems for flow assurance applications.

Understanding the formation and dissociation behavior of methane gas hydrate in marine sediments is one of the important precursors for methane gas production from the hydrate deposits. The phase behavior of gas hydrates is influenced by the presence of sediments, composition of salts and water present in it. Krishna–Godavari (KG) Basin in India is one such reservoir which has a huge potential of methane gas hydrates. Here, we have investigated the phase equilibria, and the kinetics of methane hydrate formation, and dissociation in the presence of pure water, and in aqueous solution of 10 wt% (KG) basin sediment. We observed that the phase equilibrium conditions of methane hydrate in presence of 10 wt% sediment solution got shifted to slightly higher pressures at given temperature as compared to that in the bulk phase. It has also been observed that more number of methane gas molecules are consumed in 10 wt% sediment solution in the initial 30 minutes of time than in the pure water system, revealing the promotion effect of sediment surface. The number of moles of methane gas released during the dissociation of hydrate has found to be lesser in sediment solution than in pure water at any given time after initial 55 min of the start of dissociation.