This book provides a succinct overview on the application of rate and pressure transient analysis in unconventional petroleum reservoirs. It begins by introducing unconventional reservoirs, including production challenges, and continues to explore the potential benefits of rate and pressure analysis methods. Rate transient analysis (RTA) and pressure transient analysis (PTA) are techniques for evaluating petroleum reservoir properties such as permeability, original hydrocarbon in-place, and hydrocarbon recovery using dynamic data. The brief introduces, describes and classifies both techniques, focusing on the application to shale and tight reservoirs. Authors have used illustrations, schematic views, and mathematical formulations and code programs to clearly explain application of RTA and PTA in complex petroleum systems. This brief is of an interest to academics, reservoir engineers and graduate students.

Unconventional Reservoir Rate-Transient Analysis provides petroleum engineers and geoscientists with the first comprehensive review of rate-transient analysis (RTA) methods as applied to unconventional reservoirs. Volume One—Fundamentals, Analysis Methods, and Workflow is comprised of five chapters which address key concepts and analysis methods used in RTA. This volume overviews the fundamentals of RTA, as applied to low-permeability oil and gas reservoirs exhibiting simple reservoir and fluid characteristics. Volume Two—Application to Complex Reservoirs, Exploration and Development is comprised of four chapters that demonstrate how RTA can be applied to coalbed methane reservoirs, shale gas reservoirs, and low-permeability/shale reservoirs exhibiting complex behavior such as multiphase flow. Use of RTA to assist exploration and development programs in unconventional reservoirs is also demonstrated. This book will serve as a critical guide for students, academics, and industry professionals interested in applying RTA methods to unconventional reservoirs. Gain a comprehensive review of key concepts and analysis methods used in modern rate-transient analysis (RTA) as applied to low-permeability ("tight") oil and gas reservoirs Improve your RTA methods by providing reservoir/hydraulic fracture properties and hydrocarbon-in-place estimates for unconventional gas and light oil reservoirs exhibiting complex reservoir behaviors Understand the provision of a workflow for confident application of RTA to unconventional reservoirs

Rate-transient analysis (RTA) is now one of the most important methods for reservoir and hydraulic fracture characterization used in the petroleum industry for unconventional gas and light oil reservoirs. RTA is also used as the basis for generating a production forecast. However, RTA is based primarily on analytical models that were developed for conventional reservoirs with many simplifying assumptions that often don't apply to unconventional reservoirs. Unconventional Gas and Light Oil Reservoir Rate-Transient Analysis: Volume 1 - Fundamentals delivers a critical knowledge gap to help practicing reservoir and production engineers understand the unique differences in rate-transient analysis for today's unconventional reservoirs. Starting with the fundamentals, engineers first understand the basic flow regimes and analysis methods along with the unique reservoir properties of unconventional assets. Then, the chapters progress to more advanced topics such as how to modify and apply RTA methods for each instance of shale oil/gas, coalbed methane, and tight shale oil/gas along with transforming these modified methods into higher quality production forecasting, with emphasis on analytical and semi-analytical methods. Supported by many real-world field examples covering both hydraulic fracturing and unconventional reservoirs to learn from with questions and answers to practice, Unconventional Gas and Light Oil Reservoir Rate-Transient Analysis: Volume 1 - Fundamentals supplies today's petroleum engineers with a more intelligent approach to today's more complex reservoirs. Improve reservoir flow-rate workflows specific to unconventional oil and gas reservoirs as well as complex hydraulic fracturing projects Authored by leading researcher and expert in unconventional reservoir RTA Generate stronger production forecasts with guidelines and field examples on how to deal with data uncertainties, poor data quality, and operational upsets

This reference presents a comprehensive description of flow through porous media and solutions to pressure diffusion problems in homogenous, layered, and heterogeneous reservoirs. It covers the fundamentals of interpretation techniques for formation tester pressure gradients, and pretests, multiprobe and packer pressure transient tests, including derivative, convolution, and pressure-rate and pressure-pressure deconvolution. Emphasis is placed on the maximum likelihood method that enables one to estimate error variances in pressure data along with the unknown formation parameters. Serves as a training manual for geologists, petrophysicists, and reservoir engineers on formation and pressure transient testing Offers interpretation techniques for immediate application in the field Provides detailed coverage of pretests, multiprobe and packer pressure transient tests, including derivative, convolution, and pressure-rate and pressure-pressure deconvolution

Pressure Transient Analysis: Pressure Derivative provides focuses on applications of pressure and derivative data for interpretation of pressure transient tests, offering alternatives to costly commercial software. Building from basics, this practical text spans: wells near single and multi-boundary systems, hydraulically fractured wells, naturally fractured reservoirs, interpretation of interference and pulse tests, gas well test analysis (including sources of emissions and decarbonizing strategies, geological sequestration, CCS risks and stress on CCS), multiphase flow, injectivity and falloff tests, rate transient and multi-rate tests, partially penetrated / perforated vertical and slanted wells, and horizontal wells in conventional and unconventional reservoirs. Many techniques and equations presented in this book can be found in the black box of commercial well-test analysis software packages – this practical text unlocks, unpacks, and makes critical, analytical tools accessible to core users. Delivers an alternative technique to type-curve matching using the loglog analysis Introduces simple analytical equations used in the step-by-step procedure for analyzing pressure transient tests Presents common cases encountered by practicing engineers inspired by a robust literature review, boasting over 500 diverse, global sources Includes (75) solved simulated exercises and field cases, along with (81) unsolved problems (simulated and field cases) to reinforce learning Supports sustainability and the reduction of carbon emissions by addressing carbon footprints, emissions sources and decarbonizing strategies, carbon capture, storage, and CO2 storage

Unconventional gas resources accounted for more than 50% of total U.S. gas production in 2012 and its contribution is expected to increase to 75% by 2040 (EIA, 2015). In these unconventional gas reservoirs, reservoir and fluid characteristics can be significantly different from those in conventional resources, rendering traditional production data analysis methods inadequate. Those effects include long-time transient periods due to ultra-low permeability, pressure-dependent permeability and exemplified large capillary pressure. Development of reliable analysis methods to successfully capture these complex effects demands the formulation of new solutions to the governing flow equations which consider these complex nonlinearities. It is the interest of this study to develop more rigorous performance models for these types of systems derived from fundamental governing flow equations. This study presents a series of novel and rigorous semi-analytical solutions to the governing partial differential equations applicable to single-phase gas and multiphase flow in unconventional reservoirs. Focusing on early-transient periods, the proposed semi-analytical method utilizes similarity theory to transform the system of nonlinear PDEs to ordinary differential form, which is later solved via shooting method coupled Runge-Kutta numerical integration. The work starts with early-transient single-phase gas flow in linear and radial flow regimes under constant pressure and rate production conditions, followed by its direct extension to multiphase flow system using the black-oil fluid formulation. The application of the proposed multiphase flow solution to actual productionhighlighting producing gas-oil-ratio predictionis also discussed. Additionally, the proposed semi-analytical solution is proven capable of solving the multiphase flow equations under fully compositional fluid formulation. In the last chapter, capillary pressure effectsa multiphase flow effect widely recognized to be significant in unconventional system due to nano-scale pore sizeis studied using the proposed semi-analytical method. Besides studying capillary pressure as an additional pressure drop on fluid flow, the effect of capillary pressure on phase behavior and properties is also analyzed. All the results in this work are validated by matching with finely-gridded commercial numerical simulator.