Basic concepts in the theory of seepage of homogeneous liquids in fissured rocks [strata]
01 Jan 1960-Journal of Applied Mathematics and Mechanics (JOURNAL OF APPLIED MATHEMATIC AND MECHANICS)-Vol. 24, Iss: 5, pp 1286-1303
About: This article is published in Journal of Applied Mathematics and Mechanics.The article was published on 1960-01-01. It has received 2556 citations till now.
Citations
More filters
Book•
01 Jan 1992TL;DR: A theory aiming to describe their mechanical behavior must take heed of their deformability and represent the definite principles it obeys as mentioned in this paper, which is not the case in modern physics, since it concerns solely the small particles of matter.
Abstract: Matter is commonly found in the form of materials. Analytical mechanics turned its back upon this fact, creating the centrally useful but abstract concepts of the mass point and the rigid body, in which matter manifests itself only through its inertia, independent of its constitution; “modern” physics likewise turns its back, since it concerns solely the small particles of matter, declining to face the problem of how a specimen made up of such particles will behave in the typical circumstances in which we meet it. Materials, however, continue to furnish the masses of matter we see and use from day to day: air, water, earth, flesh, wood, stone, steel, concrete, glass, rubber, ... All are deformable. A theory aiming to describe their mechanical behavior must take heed of their deformability and represent the definite principles it obeys.
2,644 citations
TL;DR: In this paper, the authors analyze measurements, conceptual pictures, and mathematical models of flow and transport phenomena in fractured rock systems, including water flow, conservative and reactive solutes, and two-phase flow.
1,267 citations
Book•
01 Jan 1986
Abstract: Evaluating Fractured Reservoirs Reservoir Management Detecting And Predicting Fracture Occurrence and Intensity Analysis Of Anisotropic Reservoirs Analysis Procedures in Fractured Reservoirs Appendix A: List of Documented Fractured Reservoirs Appendix B: Procedures Checklist Appendix C: Averaging Techniques
1,186 citations
TL;DR: In this paper, a dual-porosity model was developed for the purpose of studying variably saturated water flow and solute transport in structured soils or fractured rocks, where water in both pore systems is assumed to be mobile.
Abstract: A one-dimensional dual-porosity model has been developed for the purpose of studying variably saturated water flow and solute transport in structured soils or fractured rocks. The model involves two overlaying continua at the macroscopic level: a macropore or fracture pore system and a less permeable matrix pore system. Water in both pore systems is assumed to be mobile. Variably saturated water flow in the matrix as well as in the fracture pore system is described with the Richards' equation, and solute transport is described with the convection-dispersion equation. Transfer of water and solutes between the two pore regions is simulated by means of first-order rate equations. The mass transfer term for solute transport includes both convective and diffusive components. The formulation leads to two coupled systems of nonlinear partial differential equations which were solved numerically using the Galerkin finite element method. Simulation results demonstrate the complicated nature of solute leaching in structured, unsaturated porous media during transient water flow. Sensitivity studies show the importance of having accurate estimates of the hydraulic conductivity near the surface of soil aggregates or rock matrix blocks. The proposed model is capable of simulating preferential flow situations using parameters which can be related to physical and chemical properties of the medium.
1,109 citations
TL;DR: In this article, theoretical and experimental approaches to flow, hydrodynamic dispersion, and miscible and immiscible displacement processes in reservoir rocks are reviewed and discussed, and two different modeling approaches to these phenomena are compared.
Abstract: In this paper, theoretical and experimental approaches to flow, hydrodynamic dispersion, and miscible and immiscible displacement processes in reservoir rocks are reviewed and discussed. Both macroscopically homogeneous and heterogeneous rocks are considered. The latter are characterized by large-scale spatial variations and correlations in their effective properties and include rocks that may be characterized by several distinct degrees of porosity, a well-known example of which is a fractured rock with two degrees of porosity---those of the pores and of the fractures. First, the diagenetic processes that give rise to the present reservoir rocks are discussed and a few geometrical models of such processes are described. Then, measurement and characterization of important properties, such as pore-size distribution, pore-space topology, and pore surface roughness, and morphological properties of fracture networks are discussed. It is shown that fractal and percolation concepts play important roles in the characterization of rocks, from the smallest length scale at the pore level to the largest length scales at the fracture and fault scales. Next, various structural models of homogeneous and heterogeneous rock are discussed, and theoretical and computer simulation approaches to flow, dispersion, and displacement in such systems are reviewed. Two different modeling approaches to these phenomena are compared. The first approach is based on the classical equations of transport supplemented with constitutive equations describing the transport and other important coefficients and parameters. These are called the continuum models. The second approach is based on network models of pore space and fractured rocks; it models the phenomena at the smallest scale, a pore or fracture, and then employs large-scale simulation and modern concepts of the statistical physics of disordered systems, such as scaling and universality, to obtain the macroscopic properties of the system. The fundamental roles of the interconnectivity of the rock and its wetting properties in dispersion and two-phase flows, and those of microscopic and macroscopic heterogeneities in miscible displacements are emphasized. Two important conceptual advances for modeling fractured rocks and studying flow phenomena in porous media are also discussed. The first, based on cellular automata, can in principle be used for computing macroscopic properties of flow phenomena in any porous medium, regardless of the complexity of its structure. The second, simulated annealing, borrowed from optimization processes and the statistical mechanics of spin glasses, is used for finding the optimum structure of a fractured reservoir that honors a limited amount of experimental data.
946 citations
References
More filters
TL;DR: In this article, the authors proposed a capillary end effect which contributes to retaining a large fraction of the oil inside the "blocks" between fractures while permitting the evolution of solution gas.
Abstract: Fractured reservoir rocks may be considered as made up of at least two porosity-permeability systems: one which accounts for the largest void space fraction of the reservoir and which makes up the pore space between the grains (intergranular porosity); the other which accounts for the smallest void space fraction and which makes up the pore space of the fractures and fissures. The former generally exhibits a low permeability, whereas the latter provides channels of high permeability which are the main reservoir fluid carriers to the wells, provided sufficient lateral continuity exists. In most cases, vertical continuity of the highly permeable system is also present and gravity segregation of the reservoir fluids may exist to a large degree. Under certain conditions of re ervoir rock wettability, the fluids will segregate into two zones of saturation, a lower zone of high oil saturation and an upper zone of high gas saturation. This results in a rapidly increasing gas-oil ratio in the early stage of depletion and in a low ultimate oil recovery. An alternative explanation of the behavior of fractured reservoir is also proposed whereby the low recovery by depletion drive is explained by capillary end effect which contributes to retaining a large fraction of the oil inside the "blocks" between fractures while permitting the evolution of solution gas. This end-effect capillary retention hypothesis would be particularly effective while low pressure gradients prevail within the reservoir. The hypothesis submitted herein for the explanation of the low oil recoveries from fractured reservoirs are intended to stimulate thinking so that experiments may perhaps be designed for their verification and for finding some solution to increasing recovery from such fields. Various approaches to this problem are suggested, but they have not received as yet the sanction of field use.
36 citations
TL;DR: The Spraberry formation of West Texas is developed in the lower Leonard of middle Permian, restricted in most part to the Midland basin this article, and the main producing structure is a fractured permeability trap on a homoclinal fold.
Abstract: The Spraberry formation of West Texas is developed in the lower Leonard of middle Permian, restricted in most part to the Midland basin. The main producing structure is a fractured permeability trap on a homoclinal fold. This homogeneous mass is undifferentiated except as to alternate layers of sands, siltstones, shales, and limestones, deposited in a deep basin under stagnant conditions with hydrocarbons formed throughout the 1,000 feet of sedimentary rocks. Fractures were created by tensional forces after induration, probably during post-Leonard time. With storage of the oil reservoir in the sandstone matrix, the fractures serve as "feeder lines" to conduct the oil to the bore hole. Without these fractures commercial production would be from a seemingly "too-tight" reservoir rock. The producing area of the Spraberry formation is a "fairway" 150 miles long and 50 miles wide at an average depth of 6,800 feet. The main area, however, is 50 miles long, with width ranging from a few miles to 48 miles, thus creating a triangle of 488,000 proved and semi-proved productive acres.
22 citations