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Drilling Fluid Invasion
Drilling fluid invasion is a process that occurs in a well being drilled with higher wellbore pressure (normally caused by excessive mud weights) than formation pressure. The liquid component of the drilling fluid (known as the mud filtrate, or spurt) continues to "invade" the porous and permeable formation until the solids present in the mud, commonly bentonite, clog enough pores to form a mud cake capable of preventing further invasion. If invasion is severe enough, and reservoir pressures are unable to force the fluid and associated particles out entirely when the well starts producing, the amount of oil and gas a well can produce can be permanently reduced. This is especially true when a process called phase trapping occurs. This is when a fluid enters a formation that is below its irreducible saturation of that fluid. Once the fluid is present, it is held in place by capillary forces and usually can not be removed. Invasion also has significant implications for well l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation Pressure
Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary mineral deposit formed in a cave * Class formation, a topological group acting on a module satisfying certain conditions * Formation (group theory), a class of groups that is closed under some operations * Formation constant, an equilibrium constant for the formation of a complex in solution * Formation enthalpy, standard heat of formation of a compound * Formation (group theory), a class of groups * Formation (geology), a formally named rock stratum or geological unit * Formation of rocks, how rocks are formed * Formation and evolution of the Solar System, history of the Solar System * Rock formation, an isolated, scenic, or spectacular surface rock outcrop * Vegetation formation, a concept used to classify vegetation communities Milita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drilling Mud
In geotechnical engineering, drilling fluid, also known as drilling mud, is used to aid the drilling of boreholes into the earth. Used while drilling oil well, oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells. The two main categories of drilling fluids are water-based muds (WBs), which can be dispersed and non-dispersed, and non-aqueous muds, usually called oil-based muds (OBs). Along with their formatives, these are used along with appropriate polymer and clay additives for drilling various oil and gas formations. Gaseous drilling fluids, typically utilizing air or natural gas, sometimes with the addition of foaming agents, can be used when downhole conditions permit. The main functions of liquid drilling fluids are to exert hydrostatic pressure to prevent formation fluids from entering into the well bore, and carrying out drill cuttings as well as suspending the drill cuttings while d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mud Filtrate
Mud (, or Middle Dutch) is loam, silt or clay mixed with water. Mud is usually formed after rainfall or near water sources. Ancient mud deposits hardened over geologic time scale, geological time to form sedimentary rock such as shale or mudstone (generally called lutites). When geological deposits of mud are formed in estuaries, the resultant layers are termed bay muds. Mud has also been used for Century, centuries as a construction resource for mostly houses and also used as a binder. An Old English word for it was fen, now in English dialects, most dialects referring to a type of wetland. Building and construction Adhesive In the construction industry, mud is a semi-fluid material that can be used to coat, seal, or adhere materials. The term "mud" can be used for various semi-fluid materials used in construction including slurry, mortar (masonry), mortar, plaster, stucco, and concrete. Material Mud, Cob (material), cob, adobe, clay, and many other names are histori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bentonite
Bentonite ( ) is an Absorption (chemistry), absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelling capacity than Ca-montmorillonite. Bentonite usually forms from the weathering of volcanic ash in seawater, or by hydrothermal circulation through the porosity of volcanic ash beds, which converts (devitrification) the volcanic glass (obsidian, rhyolite, dacite) present in the ash into clay minerals. In the mineral alteration process, a large fraction (up to 40–50 wt.%) of amorphous silica is dissolution (chemistry), dissolved and leaching (agriculture), leached away, leaving the bentonite deposit in place. Bentonite beds are white or pale blue or green (traces of redox, reduced ) in fresh exposures, turning to a cream color and then yellow, red, or brown (traces of oxidation, oxidized ) as the exposure is weathered further. As a swel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mud Cake (oil And Gas)
Mud cake (also mudcake) is the layer of particulates from drill mud coating (caking) the inside of a borehole after the suspension medium has seeped through a porous geological formation. Similar to filter cake A filter cake is formed by the substances that are retained on a filter. Filter aids, such as diatomaceous earth or activated carbon are usually used to form the filter cake. The purpose is to increase flow rate or achieve a smaller micron filt .... Mud cake provides a physical barrier to prevent further penetration and loss of drilling fluid, as well a later loss of produced fluids, into a permeable formation. References Drilling technology Fluid dynamics {{Fluiddynamics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Trapping
Phase or phases may refer to: Science *State of matter, or phase, one of the distinct forms in which matter can exist *Phase (matter), a region of space throughout which all physical properties are essentially uniform *Phase space, a mathematical space in which each possible state of a physical system is represented by a point also referred to as a "microscopic state" **Phase space formulation, a formulation of quantum mechanics in phase space *Phase (waves), the position of a point in time (an instant) on a waveform cycle **Instantaneous phase, generalization for both cyclic and non-cyclic phenomena *AC phase, the phase offset between alternating current electric power in multiple conducting wires **Single-phase electric power, distribution of AC electric power in a system where the voltages of the supply vary in unison **Three-phase electric power, a common method of AC electric power generation, transmission, and distribution *Phase problem, the loss of information (the phase) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irreducible Saturation
In philosophy, systems theory, science, and art, emergence occurs when a complex entity has properties or behaviors that its parts do not have on their own, and emerge only when they interact in a wider whole. Emergence plays a central role in theories of integrative levels and of complex systems. For instance, the phenomenon of life as studied in biology is an emergent property of chemistry and physics. In philosophy, theories that emphasize emergent properties have been called emergentism. In philosophy Philosophers often understand emergence as a claim about the etiology of a system's properties. An emergent property of a system, in this context, is one that is not a property of any component of that system, but is still a feature of the system as a whole. Nicolai Hartmann (1882–1950), one of the first modern philosophers to write on emergence, termed this a ''categorial novum'' (new category). Definitions This concept of emergence dates from at least the time of Aris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Well Logging
Well logging, also known as borehole logging is the practice of making a detailed record (a ''well log'') of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface (''geological'' logs) or on physical measurements made by instruments lowered into the hole (''geophysical'' logs). Some types of geophysical well logs can be done during any phase of a well's history: drilling, completing, producing, or abandoning. Well logging is performed in boreholes drilled for the oil and gas, groundwater, mineral and geothermal exploration, as well as part of environmental, scientific and geotechnical studies. Wireline logging Different industries, as mining, oil and gas uses wireline logging to obtain a continuous record of a formation's rock properties, also, groundwater consultants. Wireline logging can be defined as being "The acquisition and analysis of geophysical data performed as a function of well b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Logging
Sonic logging is a well logging tool that provides a formation’s interval transit time, designated as t, which is a measure of a how fast elastic seismic compressional and shear waves travel through the formations. Geologically, this capacity varies with many things including lithology and rock textures, most notably decreasing with an increasing effective porosity and increasing with an increasing effective confining stress. This means that a sonic log can be used to calculate the porosity, confining stress, or pore pressure of a formation if the seismic velocity of the rock matrix, V_, and pore fluid, V_l, are known, which is very useful for hydrocarbon exploration. Process of sonic logging The velocity is calculated by measuring the travel time from the piezoelectric transmitter to the receiver, normally with the units microsecond per foot (a measure of slowness). To compensate for the variations in the drilling mud thickness, there are actually two receivers, one nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistivity Logging
Resistivity logging is a method of well logging that works by characterizing the rock or sediment in a borehole by measuring its electrical resistivity. Resistivity is a fundamental material property which represents how strongly a material opposes the flow of electric current. In these logs, resistivity is measured using four electrical probes to eliminate the resistance of the contact leads. The log must run in holes containing electrically conductive mud or water, i.e., with enough ions present in the drilling fluid. Indeed, in the borehole fluids the electrical charge carriers are only ions (cations and anions) present in aqueous solution in the fluid. In the absence of dissolved ions, water is a very poor electrical conductor. Indeed, pure water is very poorly dissociated by its self-ionisation (at 25 °C, pKw = 14, so at pH = 7, += H–= 10−7 mol/L) and thus water itself does not significantly contribute to conduct electricity in an aqueous solution. The resist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drilling Fluid
In geotechnical engineering, drilling fluid, also known as drilling mud, is used to aid the drilling of boreholes into the earth. Used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells. The two main categories of drilling fluids are water-based muds (WBs), which can be dispersed and non-dispersed, and non-aqueous muds, usually called oil-based muds (OBs). Along with their formatives, these are used along with appropriate polymer and clay additives for drilling various oil and gas formations. Gaseous drilling fluids, typically utilizing air or natural gas, sometimes with the addition of foaming agents, can be used when downhole conditions permit. The main functions of liquid drilling fluids are to exert hydrostatic pressure to prevent formation fluids from entering into the well bore, and carrying out drill cuttings as well as suspending the drill cuttings while drill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
