The success of horizontal drilling and hydraulic fracturing has enabled the economic production of hydrocarbons from shale formations. However, wellbore instability and proppant embedment remain two major concerns during drilling and completion of wellbores in unconventional shale reservoirs. Both issues are largely controlled by shale-fluid interactions. Understanding the interactions of organic-rich shale with water-based fluids is the first step towards selecting appropriate drilling and fracturing fluids. The main objective of this study is to investigate the interactions of organic-rich shale with various water-based fluids. A series of measurements were performed to determine shale mineralogy, native water activity, fluid content, pore size distribution, Brinell hardness, Young's modulus, P-wave and S-wave velocities. It was shown that XRD and XRF yield consistent shale mineralogy, allowing us to make rapid determinations of shale mineralogy. Large variations in mineralogy were observed with shale samples from different formations. Even samples from the same well and at adjacent depths exhibited very different mineralogical makeup. The NMR T1/T2 ratio and T2 secular relaxation were used to distinguish pore fluids of different viscosity in pores of various sizes. A good correlation was established between the clay content and the amount of low-viscosity fluid in small pores, indicating that the water-saturated microporosity was in clay minerals. Combined N2GA and MICP measurements showed that a majority of the shale pores were found to be in the micropore to mesopore size range. Changes in shale mechanical properties were measured before and after shale samples came into contact with water-based fluids. The small degree of swelling and mechanical properties changes suggests that these organic-rich shales were only slightly sensitive to fluid exposure. Anisotropic swelling perpendicular and parallel to bedding planes could be due to the clay fabric anisotropy. The importance of using preserved shale samples was clearly demonstrated. Temperature and fluid pH were found to have significant impact on the reduction in shale mechanical stability after fluid exposure. Changes in both shale hardness and Young's modulus were observed with fluid exposure. Shales with higher clay content tend to experience greater reduction in modulus and hardness after contact with water-based fluids. A comparison between the measured fracture permeability damage and the calculated fracture permeability damage due to proppant embedment alone reveals that proppant embedment caused by shale softening is only partially responsible for the decrease in fracture permeability. Other mechanisms such as fines mobilization may be the dominant factors controlling fracture conductivity damage. Together these measurements allow us to rapidly screen drilling and fracturing fluids that are compatible with a particular shale by studying changes in shale mechanical properties before and after contact with water-based fluids. Potentially troublesome shales can be identified and possible solutions can also be evaluated using this measurement procedure.

The primary objective of this study is to develop and improve water-based drilling fluids and fracturing fluids for organic rich shale reservoirs by using nanoparticles and to gain fundamental insight into water and oil flow in shales. This dissertation presents results for several shale formations in the US, namely the Barnett shale, the Eagle Ford shale, the Utica shale, and the Bakken shale. The research discussed here presents new methods for studying the interaction between various fluids and organic-rich shale and the development of proper methods to measure apparent and relative permeability of shale. First of all, we show how the petrophysical properties of shales are changed when they are poorly preserved. Experiments were performed to measure important petrophysical properties such as porosity, density, weight change, hardness, wave velocity and permeability before and after shale samples dried-out. The large differences in shale properties between preserved and un-preserved samples as reported herein, clearly indicate that shales should be preserved at the well site and tested with a standard procedure ensuring minimum alteration of fluids from the shale. Failure to follow a standard procedure leads to measurements that do not reflect the "true" or in-situ properties of the shale. Instead, the measurements can be a factor of 2 or 3 different from the "true" value. The shale handling, preservation and measurement techniques and procedures presented here can be used as a standard protocol for studying organic rich shales. Next, we discuss how fracturing fluid can change the petrophysical properties of shale. Among the various petrophysical properties, the fluid permeability is chosen to determine the effect of the fracturing fluid on the shale. Experimental procedures are presented to suggest how to measure the shale permeability. To measure the fluid permeability, the Pressure Penetration Technique (PPT) was developed and used. The reference permeability with sea water brine was measured and then fracturing fluid was injected into the shale. The brine permeability was re-measured to see the effect of exposure to the fracturing fluid, and experimental data show the permeability change due to fracturing fluid plugging the shale. Next, we focus on the development of a Water Based Mud (WBM) system for organic-rich shale. Drilling through a shale formation can result in borehole instability problems, and this is known to add substantial costs to the operation. This is because conventional drilling fluids tend to interact with clay minerals in shales, and the mechanical properties of rock are changed by clay swelling. To reduce the interaction between water-based muds and shales, we need to reduce water invasion into the shale. The addition of nanoparticle additives to water-based drilling fluids can significantly reduce the invasion. We report results for shale permeability and pressure penetration though shales using different fluids: brine, base mud and nanoparticle based muds. To better define the effect of nanoparticles, we used different concentrations of nanoparticles in the mud. From the large reduction in permeability and the pressure response results, we clearly show that nanoparticles act as good shale inhibitors to ensure wellbore stability during drilling. Experimental studies used to measure the relative permeability of shale. Such measurements have never been done before. Due to the extremely low permeability of shale, it is very difficult to measure the relative permeability of shale directly. We propose a method of relative permeability measurement using NMR (Nuclear Magnetic Resonance) spectroscopy to measure fluid saturations and a RPC (relative permeability measurements under a confining pressure) set-up to conduct the displacement. RPC set-up is a newly developed forced injection set-up using the unsteady-state method. The in-situ fluid saturation was successfully measured with NMR, and the set-up was also useful for measuring the relative permeability of shale. It yielded continuous results from the Bakken shale tests

Clay Science in Drilling and Drilling Fluids starts from the fundamentals of clay science and drilling, then comprehensively presents the advances of clay science related to drilling and drilling fluids and ends with discussion of industrial clay products. The topics combine to present the whole picture of fundamental research and industrial applications of clays and clay minerals in drilling operations, which is of general interest to researchers and engineers working in the related fields.Oil and gas are the primary sources of energy in human society and the foundation of the petrochemical industry. However, extracting these resources present a number of drilling challenges, including high temperature and high pressure (HTHP), offshore drilling, high angle drilling, and even horizontal drilling, among others. As a result, it is crucial to develop advanced drilling and drilling fluid technologies. Clay science in drilling and drilling fluids should be clarified for this purpose because clays and clay minerals are one of the most important components of drilling fluids and have a significant impact on wellbore stability. Clay Science in Drilling and Drilling Fluids covers the different levels of clay science in drilling and drilling fluids, i.e., form fundamentals, the latest research results, applications, and commercial products. Covers the fundamentals of clay minerals, drilling, and drilling operations Discusses applications of the research and science to real world problems Introduces available commercial clay products and recommends their use for specific situations

This book presents selected papers from the 7th International Field Exploration and Development Conference (IFEDC 2017), which focus on upstream technologies used in oil & gas development, the principles of the process, and various design technologies. The conference not only provides a platform for exchanging lessons learned, but also promotes the development of scientific research in oil & gas exploration and production. The book will benefit a broad readership, including industry experts, researchers, educators, senior engineers and managers.

Fluid-Solid Interactions in Upstream Oil and Gas Applications, Volume 78 delivers comprehensive understanding of fluid-rock interactions in oil and gas reservoirs and their impact on drilling, production, and reservoir hydrocarbon management. The book is arranged based on intervals of the oil and gas production process and introduces the basics of reservoir fluids and their properties, along with the rheological behavior of solid-fluid systems across all stages of the reservoir, including drilling processes, acidizing, and fracking. The reference then addresses different application-specific issues, such as solid-fluid interactions in tight reservoirs, the applications of nanoparticles, interactions during the EOR processes, and environmental concerns. Introduces the basics of reservoir fluids and their properties as well as the rheological behavior of solid-fluid systems Discusses the latest advances in molecular simulations and their reliability Highlights the environmental concerns regarding the application of fluid-solid systems

Groundwater Science, Second Edition — winner of a 2014 Textbook Excellence Award (Texty) from The Text and Academic Authors Association — covers groundwater's role in the hydrologic cycle and in water supply, contamination, and construction issues. It is a valuable resource for students and instructors in the geosciences (with focuses in hydrology, hydrogeology, and environmental science), and as a reference work for professional researchers. This interdisciplinary text weaves important methods and applications from the disciplines of physics, chemistry, mathematics, geology, biology, and environmental science, introducing you to the mathematical modeling and contaminant flow of groundwater. New to the Second Edition: New chapter on subsurface heat flow and geothermal systems Expanded content on well construction and design, surface water hydrology, groundwater/ surface water interaction, slug tests, pumping tests, and mounding analysis. Updated discussions of groundwater modeling, calibration, parameter estimation, and uncertainty Free software tools for slug test analysis, pumping test analysis, and aquifer modeling Lists of key terms and chapter contents at the start of each chapter Expanded end-of-chapter problems, including more conceptual questions Winner of a 2014 Texty Award from the Text and Academic Authors Association Features two-color figures Includes homework problems at the end of each chapter and worked examples throughout Provides a companion website with videos of field exploration and contaminant migration experiments, PDF files of USGS reports, and data files for homework problems Offers PowerPoint slides and solution manual for adopting faculty

Emerging Technologies in Hydraulic Fracturing and Gas Flow Modelling features the latest strategies for exploiting depleted and unconventional petroleum rock formations as well as simulating associated gas flow mechanisms. The book covers a broad range of multivarious stimulation methods currently applied in practice. It introduces new stimulation techniques including a comprehensive description of interactions between formation/hydraulic fracturing fluids and the host rock material. It provides further insight into practices aimed at advancing the operation of hydrocarbon reservoirs and can be used either as a standalone resource or in combination with other related literature. The book can serve as a propaedeutic resource and is appropriate for those seeking rudimentary information on the exploitation of ultra-impermeable oil and gas reservoirs. Professionals and researchers in the field of petroleum, civil, oil and gas, geotechnical and geological engineering who are interested in the production of unconventional petroleum resources as well as students undertaking studies in similar subject areas will find this to be an instructional reference.