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Amott Test
The Amott test is one of the most widely used empirical wettability measurements for reservoir cores in petroleum engineering. The method combines two spontaneous imbibition measurements and two forced displacement measurements. This test defines two different indices: the Amott water index (I_w) and the Amott oil index (I_o). Amott–Harvey index The two Amott indices are often combined to give the Amott–Harvey index. It is a number between −1 and 1 describing wettability of a rock in drainage processes. It is defined as: :AI=I_w-I_o These two indices are obtained from special core analysis (SCAL) experiments ( porous plate or centrifuge) by plotting the capillary pressure curve as a function of the water saturation as shown on figure 1: :I_w=\frac with S_ is the water saturation for a zero capillary pressure during the imbibition process, S_ is the irreducible water saturation and S_ is the residual oil saturation after imbibition. :I_o=\frac with S_ is the oil saturation f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wettability
Wetting is the ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. This happens in presence of a gaseous phase or another liquid phase not miscible with the first one. The degree of wetting (wettability) is determined by a force balance between adhesive and cohesive forces. Wetting is important in the bonding or adherence of two materials. Wetting and the surface forces that control wetting are also responsible for other related effects, including capillary effects. There are two types of wetting: non-reactive wetting and reactive wetting. Wetting deals with three phases of matter: gas, liquid, and solid. It is now a center of attention in nanotechnology and nanoscience studies due to the advent of many nanomaterials in the past two decades (e.g. graphene, Carbon nano tube, carbon nanotube, boron nitride nanomesh). Explanation Adhesive forces between a liquid and solid cause a liquid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imbibition
Imbibition is a special type of diffusion that takes place when liquid is absorbed by solids-colloids causing an increase in volume. Water surface potential movement takes place along a concentration gradient; some dry materials absorb water. A gradient between the absorbent and the liquid is essential for imbibition. For a substance to imbibe a liquid, there must first be some attraction between them. Imbibition occurs when a wetting fluid displaces a non-wetting fluid, the opposite of drainage in which a non-wetting phase displaces the wetting fluid. The two processes are governed by different mechanisms. Imbibition is also a type of diffusion since water movement is along the concentration gradient. The seeds and other such materials have almost no water hence they absorb water easily. Water potential gradient between the absorbent and liquid imbibed is essential for imbibition. Examples One example of imbibition in nature is the absorption of water by hydrophilic colloids. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lak Wettability Index
In petroleum engineering, Lak wettability index, developed by Abouzar Mirzaei-Paiaman is a quantitative indicator to measure wettability of rocks from relative permeability data. This index is based on a combination of Craig's first rule. and modified Craig's second rule :I_ = \frac + \frac + \frac where :I_ : Lak wettability index (index values near -1 and 1 represent strongly oil-wet and strongly water-wet rocks, respectively) :k_ : Water relative permeability measured at residual oil saturation :CS : Water saturation at the intersection point of water and oil relative permeability curves (fraction) :Sor : Residual oil saturation (in fraction) :Swc : Irreducible water saturation (in fraction) :RCS : Reference crossover saturation (in fraction) defined as: :RCS = 0.5 + \frac and A and B are two constant coefficients defined as: :A = 0.5 and B = 0 if k_ < 0.3 : and if : |
Rise In Core
The rise in core (RIC) method is an alternate reservoir wettability characterization method described by S. Ghedan and C. H. Canbaz in 2014. The method enables estimation of all wetting regions such as strongly water wet, intermediate water, oil wet and strongly oil wet regions in relatively quick and accurate measurements in terms of Contact angle rather than wettability index. During the RIC experiments, core samples saturated with selected reservoir fluid were subjected to imbibition from a second reservoir fluid. RIC wettability measurements are compared with and modified – Amott test and United States Bureau of Mines, USBM measurements using core plug pairs from different heights of a thick Carbonated water, carbonate reservoir. Results show good coherence. The RIC method is an alternate method to Amott and USBM methods and that efficiently characterizes Reservoir Wettability. Cut-off values vs wettability index One study used the water advancing contact angle to estima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TEM-function
In petroleum engineering, TEM (true effective mobility), also called TEM-function developed by Abouzar Mirzaei-Paiaman, is a criterion to characterize dynamic two-phase flow characteristics of rocks (or dynamic rock quality). TEM is a function of relative permeability, porosity, absolute permeability and fluid viscosity, and can be determined for each fluid phase separately. TEM-function has been derived from Darcy's law for multiphase flow. :\mathit = \frac in which k is the absolute permeability, k_\mathit is the relative permeability, φ is the porosity, and μ is the fluid viscosity. Rocks with better fluid dynamics (i.e., experiencing a lower pressure drop in conducting a fluid phase) have higher TEM versus saturation curves. Rocks with lower TEM versus saturation curves resemble low quality systems. TEM-function in analyzing relative permeability data is analogous with Leverett J-function In petroleum engineering, the Leverett ''J''-function is a dimensionless function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Permeability
In multiphase flow in porous media, the relative permeability of a phase is a dimensionless measure of the effective permeability of that phase. It is the ratio of the effective permeability of that phase to the absolute permeability. It can be viewed as an adaptation of Darcy's law to multiphase flow. For two-phase flow in porous media given steady-state conditions, we can write :q_i = -\frac \nabla P_i \qquad \text \quad i=1,2 where q_i is the flux, \nabla P_i is the pressure drop, \mu_i is the viscosity. The subscript i indicates that the parameters are for phase i. k_i is here the phase permeability (i.e., the effective permeability of phase i), as observed through the equation above. Relative permeability, k_, for phase i is then defined from k_i = k_k, as :k_ = k_i / k where k is the permeability of the porous medium in single-phase flow, i.e., the absolute permeability. Relative permeability must be between zero and one. In applications, relative permeability is of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiphase Flow
In fluid mechanics, multiphase flow is the simultaneous flow of materials with two or more thermodynamic phases. Virtually all processing technologies from cavitating pumps and turbines to paper-making and the construction of plastics involve some form of multiphase flow. It is also prevalent in many natural phenomena. These phases may consist of one chemical component (e.g. flow of water and water vapour), or several different chemical components (e.g. flow of oil and water). A phase is classified as ''continuous'' if it occupies a continually connected region of space (as opposed to ''disperse'' if the phase occupies disconnected regions of space). The continuous phase may be either gaseous or a liquid. The disperse phase can consist of a solid, liquid or gas. Two general topologies can be identified: ''disperse'' flows and ''separated'' flows.'' ''The former consists of finite particles, drops or bubbles distributed within a continuous phase, whereas the latter consists of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leverett J-function
In petroleum engineering, the Leverett ''J''-function is a dimensionless function of water saturation describing the capillary pressure, :J(S_w) = \frac where S_w is the water saturation measured as a fraction, p_c is the capillary pressure (in pascal), k is the permeability (measured in m²), \phi is the porosity (0-1), \gamma is the surface tension (in N/m) and \theta is the contact angle. The function is important in that it is constant for a given saturation within a reservoir, thus relating reservoir properties for neighboring beds. The Leverett ''J''-function is an attempt at extrapolating capillary pressure data for a given rock to rocks that are similar but with differing permeability, porosity and wetting properties. It assumes that the porous rock can be modelled as a bundle of non-connecting capillary tubes, where the factor \sqrt is a characteristic length of the capillaries' radii. This function is also widely used in modeling two-phase flow of proton-excha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary Pressure
In fluid statics, capillary pressure () is the pressure between two immiscible fluids in a thin tube (see capillary action), resulting from the interactions of forces between the fluids and solid walls of the tube. Capillary pressure can serve as both an opposing or driving force for fluid transport and is a significant property for research and industrial purposes (namely microfluidic design and oil extraction from porous rock). It is also observed in natural phenomena. Definition Capillary pressure is defined as: :p_c=p_-p_ where: :p_is the capillary pressure :p_ is the pressure of the non-wetting phase :p_ is the pressure of the wetting phase The wetting phase is identified by its ability to preferentially diffuse across the capillary walls before the non-wetting phase. The "wettability" of a fluid depends on its surface tension, the forces that drive a fluid's tendency to take up the minimal amount of space possible, and it is determined by the contact angle of the fluid.Fan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core Sample
A core sample is a cylindrical section of (usually) a naturally-occurring substance. Most core samples are obtained by drilling with special drills into the substance, such as sediment or rock, with a hollow steel tube, called a core drill. The hole made for the core sample is called the "core hole". A variety of core samplers exist to sample different media under different conditions. More continue to be invented on a regular basis. In the coring process, the sample is pushed more or less intact into the tube. Removed from the tube in the laboratory, it is inspected and analyzed by different techniques and equipment depending on the type of data desired. Core samples can be taken to test the properties of manmade materials, such as concrete, ceramics, some metals and alloys, especially the softer ones. Core samples can also be taken of living things, including human beings, especially of a person's bones for microscopic examination to help diagnose diseases. Methods The compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Drainage
Secondary may refer to: Science and nature * Secondary emission, of particles ** Secondary electrons, electrons generated as ionization products * The secondary winding, or the electrical or electronic circuit connected to the secondary winding in a transformer * Secondary (chemistry), a term used in organic chemistry to classify various types of compounds * Secondary color, color made from mixing primary colors * Secondary mirror, second mirror element/focusing surface in a reflecting telescope * Secondary craters, often called "secondaries" * Secondary consumer, in ecology * An obsolete name for the Mesozoic in geosciences * Secondary feathers, flight feathers attached to the ulna on the wings of birds Society and culture * Secondary (football), a position in American football and Canadian football * Secondary dominant in music * Secondary education, education which typically takes place after six years of primary education ** Secondary school, the type of school at the secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrifuge
A centrifuge is a device that uses centrifugal force to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities (e.g. cream from milk) or liquids from solids. It works by causing denser substances and particles to move outward in the radial direction. At the same time, objects that are less dense are displaced and moved to the centre. In a laboratory centrifuge that uses sample tubes, the radial acceleration causes denser particles to settle to the bottom of the tube, while low-density substances rise to the top. A centrifuge can be a very effective filter that separates contaminants from the main body of fluid. Industrial scale centrifuges are commonly used in manufacturing and waste processing to sediment suspended solids, or to separate immiscible liquids. An example is the cream separator found in dairies. Very high speed centrifuges and ultracentrifuges able to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
