Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction

This paper discusses the migration of petroleum from its formation in a source rock to its subsequent possible entrapment in a reservoir. The chemical and physical properties of petroleum gases and liquids are stressed, particularly their phase behaviour under subsurface conditions which is shown to be a very important factor in determining migration behaviour. Engineering correlations are presented for estimating the properties of petroleum fluids under geologically realistic conditions. The directions and magnitudes of the forces acting on migrating petroleum are deduced from the combined effects of buoyancy and water flow in compacting sediments. These forces are combined, using a fluid potential description. This procedure allows the direction of migration to be denned. The rate of migration is then estimated from the properties of the sediments involved, allowing a distinction to be made between ‘lateral’ and ‘vertical’ carrier beds. This simplified approach is suitable for rapid predictive calculations in petroleum exploration. It is compared with the more complex 3-D computer modelling approaches which are currently becoming available. Migration losses are related to the cumulative pore volume employed by the petroleum in establishing a migration pathway. The petroleum migration mechanism is shown to be predominantly by bulk flow, with a small diffusive contribution for light hydrocarbons over distances less than c. 100 m. The loss factors involved in secondary migration are estimated from field evidence. The mechanism of reservoir filling is presented as a logical extension to those described for migration. This, together with the inefficiency of in-reservoir mixing by diffusion or convection, is shown to tend to cause significant lateral compostional gradients in reservoirs over and above the gravitationally induced vertical gradients described by other workers.

The movement and entrapment of petroleum fluids in the subsurface

Fault zone permeability in outcrop is quantified by detailed geologic mapping and by measurements using a minipermeameter. Deformation bands, zones of deformation bands, and slip planes are structural elements associated with successive stages in the evolution of a fault zone in porous sandstones. Deformation bands have a porosity about one order of magnitude less than the surrounding host rock and, on average, a permeability three orders of magnitude less than the surrounding host rock. The intensity of cataclasis and the clay content control the amount of permeability reduction as measured perpendicular to a band. The wall rock in proximity to slip planes can have permeabilities more than seven orders of magnitude less than the pristine sandstone. Capillary pressure wit in deformation bands is estimated to be 10-100 times larger than that in the surrounding host rock. Thus, deformation bands and slip planes can substantially modify fluid flow properties of a reservoir and have potential sealing capabilities with respect to a nonwetting phase, as evident in outcrop exposure.

Effect of Faulting on Fluid Flow in Porous Sandstones: Petrophysical Properties

1. The Role of Petroleum Production Engineering. 2. Production from Undersaturated Oil Reservoirs. 3. Production from Two-Phase Reservoirs. 4. Production from Natural Gas Reservoirs. 5. The Near-Wellbore Condition and Damage Characterization Skin Effects. 6. Gravel Pack Completions. 7. Wellbore Flow Performance. 8. Well Deliverability. 9. Forecast of Well Production. 10. Wellhead and Surface Gathering Systems. 11. Modern Well Test Analysis. 12. Well Test Design and Data Acquisition. 13. Production Logging Measurements and Analysis. 14. Well Diagnosis with Production Logging. 15. Pressure Transient Testing with Measured Sandface Flow Rates. 16. Gas Well Testing. 17. Matrix Simulation-Chemistry of Acid Rock Reactions. 18. Sandstone Acidizing Design. 19. Carbonate Acidizing Design. 20. Hydraulic Fracturing for Well Simulation. 21. Design of Hydraulic Fracture Treatments. 22. The Performance of Hydraulically-Fractured and Long-Flowing Wells. 23. Gas Lift. 24. Pump-Assisted Lift. 25. Petroleum System Analysis. 26. Environmental Issues in Petroleum Production. Appendix.

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Petroleum production systems

Hydrocarbon production, gas recovery from shale, CO2 storage and water management have a common scientific underpinning: multiphase flow in porous media. This book provides a fundamental description of multiphase flow through porous rock, with emphasis on the understanding of displacement processes at the pore, or micron, scale. Fundamental equations and principal concepts using energy, momentum, and mass balance are developed, and the latest developments in high-resolution three-dimensional imaging and associated modelling are explored. The treatment is pedagogical, developing sound physical principles to predict flow and recovery through complex rock structures, while providing a review of the recent literature. This systematic approach makes it an excellent reference for those who are new to the field. Inspired by recent research, and based on courses taught to thousands of students and professionals from around the world, it provides the scientific background necessary for a quantitative assessment of multiphase subsurface flow processes, and is ideal for hydrology and environmental engineering students, as well as professionals in the hydrocarbon, water and carbon storage industries.

Multiphase Flow in Permeable Media: A Pore-Scale Perspective

1. Some Basic Concepts in Reservoir Engineering. 2. PVT Analysis for Oil. 3. Material Balance Applied to Oil Reservoirs. 4. Darcy's Law and Applications. 5. The Basic Differential Equation for Radial Flow in a Porous Medium. 6. Well Inflow Equations for Stabilized Flow Conditions. 7. The Constant Terminal Rate Solution of the Radial Diffusivity Equation and its Application to Oilwell Testing. 8. Real Gas Flow: Gas Well Testing. 9. Natural Water Influx. 10. Immiscible Displacement. Indexes. Exercises.

L. P. Dake

Papers

Fundamentals of reservoir engineering