449 results about "Capillary pressure" patented technology

The present Invention relates to hydrocarbon well stimulation, and more particularly to methods and compositions to remove (or more generally to transfer) fluid introduced into the subsurface. For instance, preferred methods involve creating then exploiting a capillary pressure gradient at the fracture face to induce fluid flow from the fracture into the formation thereby increasing effective fracture length, and then improving fracture conductivity.

The invention relates to a method for continuously quantitative evaluation of pore structures of reservoir strata by utilizing nuclear magnetic resonance well logging data, so as to divide types of the reservoir strata. The method comprises the following steps of: classifying T2 spectrums according to parameters reflecting differences of reservoir strata, and carrying out a nonlinear calibration method on different T2 spectrums to obtain a continuously distributed capillary pressure curve of the reservoir strata; obtaining continuous reservoir stratum pore throat radius distribution and pore structure parameters by utilizing the nuclear magnetic capillary pressure curve; and evaluating the pore structure of each reservoir stratum on the basis of the nuclear magnetic capillary pressure curve, the features of the reservoir stratum pore throat radius distribution and the pore structure parameters, and dividing types of the reservoir strata. Through the adoption of the method, the nuclear magnetic capillary pressure curve on each depth point can be continuously obtained by utilizing the nuclear magnetic resonance well logging data, the pore structure of each reservoir stratum can be quantitatively evaluated according to the reservoir stratum pore throat radius distribution and the pore structure parameters of the reservoir stratum, and the types of the reservoir strata are classified, therefore, the exploitation and development efficiency of complicated oil-gas reservoir is improved.

The present invention relates to a method and system for integrating logging tool data and digital rock physics to estimate rock formation properties. A rock sample from a logging tool such as a sidewall plug or large enough cutting can be extracted by the logging tool at approximately the same well bore location that the logging tool measures fluid properties. The rock samples thus obtained is scanned using a CT scanner, scanning electron microscope or other suitable scanning device. The resulting scanned rock image can be segmented and rock properties comprising porosity, absolute permeability, relative permeability, capillary pressure and other relevant rock properties are calculated. The resulting digital calculations are integrated with logging tool data and rock property estimates to improve the accuracy and timeliness of the logging tool data.

A phased array antenna apparatus has a plurality of circuit portions which are each coupled to a respective antenna element. Capillary pressure of a cooling fluid within a wick in a loop is utilized to urge the fluid to travel around the loop, the wick being disposed in the region of the circuitry. In a variation, there are plural wicks in respective evaporators, and cooling fluid is distributed among the evaporators through a series of T-junctions. In another variation, cooling fluid is distributed to a plurality of evaporators in a sequence corresponding to a progressive increase in the respective amounts of heat accepted by the evaporators from structure being cooled.

The invention discloses a method for reconstructing a digital rock core and pore network model based on a random fractal theory. The method comprises the following steps of based on the multiple fractal features of a porous medium, performing fractal representing on a capillary pressure curve obtained by the conventional mercury intrusion method, inferring fractal expressions of random distribution density function, average value and variance by a random distribution theory, and combining the random theory and the multiple fractal theory to construct a digital rock core, so as to rapidly construct a three-dimensional micro-network model. The method has the advantages that the cost is low and is reduced; the capillary pressure curve is measured by the mercury intrusion method, the full-section rock core is used in experiment, and a micro-pore structure is fully displayed. According to the method, the computing method is simple and convenient, and the advanced method is adopted; the micro-pore structure of reservoir rock is complicated and irregular, and an extremely complicated system cannot be accurately described by the traditional classical theory, so after the method combines the multiple fractal theory and the random distribution theory, the micro-pore structure can be accurately represented, and the method is easily implemented by programming.

A method and apparatus are provided for measuring a parameter such as capillary pressure in porous media such as rock samples. The method comprises mounting a sample in a centrifuge such that different portions of the sample are spaced at different distances from the centrifuge axis, rotating the sample about the axis, measuring a first parameter in the different portions of the sample, and determining the value of a second parameter related to the force to which each portion is subjected due to rotation of the sample. In one embodiment, the first parameter is relative saturation of the sample as measured by MRI techniques, and the second parameter is capillary pressure.

The invention provides a method and a device for confirming the rock permeability. The method comprises the following steps: measuring a series of selected rock core samples to obtain rock permeability values; measuring transverse relaxation time T2 distribution and rock core capillary pressure curves of water-saturated rock core samples with different permeability values; confirming the relationship of the transverse relaxation time T2 distribution of the rock core samples and pore throat radius distribution of the rock core samples according to a function relationship of the transverse relaxation time T2 distribution and the rock core capillary pressure curves; uniformly dividing the transverse relaxation time T2 distribution and the pore throat radius distribution of the rock core samples into n groups; and calculating porosity components and average pore throat radiuses of the different groups of rock core samples. The rock permeability is confirmed by dividing the plurality groups of porosity components and average pore throat radius components through the nuclear magnetic resonance T2 distribution. The seepage characteristics of reservoir rocks are reflected in a relatively real manner through the permeability calculated by using the method and the device provided by the invention, the consistency with the rock core analysis permeability result is good, and the calculation result is accurate.

Methods and apparatus for depositing a high density biological or chemical array onto a solid support. Specifically, the apparatus is made up of a plurality of open ended channels collectively forming a matrix. The matrix has been redrawn and cut such that the pitch of the channels on the loading end is larger than the pitch of the channels on the liquid delivery end. The upper portion of each channel serves as a reservoir, while the opposing end, which has been formed by the redrawing process, is diametrically sized such that liquid in the reservoir is retained by capillary pressure at the delivery end. At any point along the height of the capillary reservoir device, all cross-sectional dimensions and areas are uniformly reduced. In other words, the on-center orientation of any two channels, also referred to as the pitch between 2 channels, measured as a function of the diameter of any cross section, is constant throughout the structure. The liquid within the channels is either printed directly from the tool onto a substrate or transferred to a substrate by a typographical pin plate. In another embodiment, the device may be used in transferring sample between multiwell plates of different well density.

The invention discloses a method for calculating tight sandstone reservoir permeability based on hole feature parameters. The method includes the steps of calculating hole structural parameters through a rock core mercury penetration experiment, establishing a permeability well logging interpretation model through a first characteristic function which is established through the hole structural parameters, converting nuclear magnetism T2 spectrum into a pseudo capillary pressure curve through correlations existing between nuclear magnetism T2 spectrum distribution and mercury penetration hole diameter distribution, and calculating the reservoir permeability according to a second characteristic function which is established through the pseudo capillary pressure curve. In practical application, the quantitative, continuous and high-precision pseudo capillary pressure curve is obtained through nuclear magnetic resonance well logging information under the condition that laboratory mercury penetration information does not exist, and finally, calculation of the reservoir permeability is conducted according to the second characteristic function which is established through the pseudo capillary pressure curve.

Methods and apparatus for depositing a high density biological or chemical array onto a solid support. Specifically, the apparatus is made up of a plurality of open ended channels collectively forming a matrix. The matrix has been redrawn and cut such that the pitch of the channels on the loading end is larger than the pitch of the channels on the liquid delivery end. The upper portion of each channel serves as a reservoir, while the opposing end, which has been formed by the redrawing process, is diametrically sized such that liquid in the reservoir is retained by capillary pressure at the delivery end. At any point along the height of the capillary reservoir device, all cross-sectional dimensions and areas are uniformly reduced. In other words, the on-center orientation of any two channels, also referred to as the pitch between 2 channels, measured as a function of the diameter of any cross section, is constant throughout the structure. The liquid within the channels is either printed directly from the tool onto a substrate or transferred to a substrate by a typographical pin plate. In another embodiment, the device may be used in transferring sample between multiwell plates of different well density.

The invention consists of an evaporative cooling device comprising one or more microchannels whose cross section is axially reduced to control the maximum capillary pressure differential between liquid and vapor phases. In one embodiment, the evaporation channels have a rectangular cross section that is reduced in width along a flow path. In another embodiment, channels of fixed width are patterned with an array of microfabricated post-like features such that the feature size and spacing are gradually reduced along the flow path. Other embodiments incorporate bilayer channels consisting of an upper cover plate having a pattern of slots or holes of axially decreasing size and a lower fluid flow layer having channel widths substantially greater than the characteristic microscale dimensions of the patterned cover plate. The small dimensions of the cover plate holes afford large capillary pressure differentials while the larger dimensions of the lower region reduce viscous flow resistance.

The invention provides a formation factor determining method and an oil saturation determining method, wherein the formation factor determining method comprises the following steps of: selecting a representative series core of a secondary pore development low-percolation oil-gas layer; measuring and obtaining a core porosity degree phi, a percolation rate K, a capillary pressure curve Pc and an average pore-throat semidiameter, wherein the core porosity degree phi is used for reflecting conductive fluid volume and a conductive path in rock, and the conductive fluid volume and the conductive path in the rock are used as parameters for determining a formation factor F. The invention has the specific relational expression: determining the formation factor according to the conductive fluid volume and the conductive path, and factors a, b and c are obtained by calibrating core data. The invention introduces the conductive fluid volume and the conductive path as the parameters to determine the formation factor, and a formation factor calculation result more conforms to an actual formation condition for determining a more accurate oil saturation result.

A modelling method having application to petroleum production, soil cleaning, etc. for optimizing faster and more realistically the displacement conditions, in a porous medium wettable by a first fluid (water for example), of a mixture of fluids including this wetting fluid, another, non-wetting fluid (oil for example) and a gas. The method comprises experimental determination of the variation curve of the capillary pressure in the pores as a function of the saturation in the liquid phases, modelling the pores of the porous medium by means of a distribution of capillaries with a fractal distribution by considering, in the case of a three-phase water (wetting fluid)-oil-gas mixture for example, a stratification of the constituents in the pores, with the water in contact with the walls, the gas in the center and the oil forming an intercalary layer, determination, from this capillary pressure curve, of the fractal dimension values corresponding to a series of given values of the saturation in the liquid phase, modelling the hysteresis effects that modify the mobile saturations of the fluids effectively displaced in the sample, that vary during drainage and imbibition cycles.

A variable discretization method for general multiphase flow simulation in a producing hydrocarbon reservoir. For subsurface regions for which a regular or Voronoi computational mesh is suitable, a finite difference / finite volume method (“FDM”) is used to discretize numerical solution of the differential equations governing fluid flow (101). For subsurface regions with more complex geometries, a finite element method (“FEM”) is used. The invention combines FDM and FEM in a single computational framework (102). Mathematical coupling at interfaces between different discretization regions is accomplished by decomposing individual phase velocity into an averaged component and a correction term. The averaged velocity component may be determined from pressure and averaged capillary pressure and other properties based on the discretization method employed, while the velocity correction term may be computed using a multipoint flux approximation type method, which may be reduced to two-point flux approximation for simple grid and permeability fields.

A capillary system for performing surface assays comprising a capillary pump containing at least two zones having different capillary pressures for obtaining controlled flow rate of liquids. The different pressure zones may be created by various means such as by creating posts in the walls of the capillary pump, by having different sized capillary of the different zones, by changing the wetting properties, by defining friction at the walls of the pump or by combinations of any of the above. The capillary system finds use in various surface assays and can be programmed for defining the volume and rate of liquid flowing through the test sites. A microfluidic chip containing assembly of programmed capillary systems for performing need based specific assays and modifications thereof.

Apparatus for forward and reverse transfer of fluids through capillaries, consisting of at least one capillary, a pressure generating or housing means, which preferably includes a box, having first and second means for aligning the capillaries from one set of wells to a second set of wells, and applied pressure differential transfers small amounts of liquid uniformly and in parallel. A method of accurately controlling a desired volume of fluid flow is particularly useful for transferring liquids to and from a microtiter dish to a Capillary Array Electrophoresis Microplate having liquid wells spaced in a radially symmetric configuration, or for maximizing desired transfer of the like or improved novel enhanced patterned arrays.

Methods and apparatus for depositing a high density biological or chemical array onto a solid support. Specifically, the apparatus is made up of a plurality of open ended channels collectively forming a matrix. The matrix has been redrawn and cut such that the pitch of the channels on the loading end is larger than the pitch of the channels on the liquid delivery end. The upper portion of each channel serves as a reservoir, while the opposing end, which has been formed by the redrawing process, is diametrically sized such that liquid in the reservoir is retained by capillary pressure at the delivery end. At any point along the height of the capillary reservoir device, all cross-sectional dimensions and areas are uniformly reduced. In other words, the on-center orientation of any two channels, also referred to as the pitch between 2 channels, measured as a function of the diameter of any cross section, is constant throughout the structure. The liquid within the channels is either printed directly from the tool onto a substrate or transferred to a substrate by a typographical pin plate. In another embodiment, the device may be used in transferring sample between multiwell plates of different well density.

A planar heat pipe for transferring heat between a higher temperature region and a lower temperature region includes a bottom facesheet, a top facesheet, a vapor-venting arterial wick between the bottom facesheet and the top facesheet and including a high permeability layer and a high capillary pressure layer each having pores such that an average pore hydraulic diameter in the high permeability layer is greater than an average pore diameter in the high capillary pressure layer. The pipe also includes an architected mechanical core structure between the arterial wick and the top facesheet, and a working fluid between the bottom facesheet and the top facesheet. The architected mechanical core structure may have a vapor region, and the vapor-venting arterial wick may have a liquid region.

A heat pipe (10) includes a pipe body (20) having an inner wall (22) and a screen mesh (30) disposed on the inner wall of the pipe body. The screen mesh is in the form of a multi-layer structure with at least one layer thereof having an average pore size different from that of the other layers. The layer with large-sized pores is capable of reducing the flow resistance to the condensed fluid to flow back, whereas the layer with small-size pores is capable of providing a relatively large capillary pressure for drawing the condensed fluid from the condensing section to the evaporating section.

The invention provides a panel heat pipe with an embedded porous wick and a manufacturing method thereof. The panel heat pipe comprises an upper metal cover plate, a lower metal cover plate, and a closed cavity is formed between the upper metal cover plate and the lower metal cover plate in a welded and sealed mode. The cavity is filled with liquid working media. The inner surface of the cavity is divided into an evaporation face and a condensation face. The condensation face and the evaporation face are paved with a thin-layer porous wick structure formed by sintering metal powder particles. Sintering porous columns with inner grooves which are distributed in an array mode are machined on the evaporation face. Porous protrusions matched with the inner grooves are machined in the condensation face. The sintering porous columns and the porous protrusions are in close fit to form an embedded porous structure column. A working medium backflow channel is formed in the embedded porous structure column. According to the panel heat pipe, the capillary pressure is improved, the working medium backflow speed is remarkably increased, vapor-liquid two-phase separation is achieved, and the heat transfer performance is greatly improved; meanwhile, the embedded wick plays a supporting column role, and panel heat pipe inward sinking or crack deformation or other problems are effectively avoided.

A method (50) for making a heat pipe (10) includes the following steps: a) providing a screen mesh (30) in the form of a multi-portion structure with at least one portion having an average pore size different from that of the other portions; b) rolling the screen mesh into a hollow column form; c) inserting the screen mesh into a hollow pipe body (22) of the heat pipe; d) sintering the screen mesh received therein at a predetermined temperature; and e) filling a working fluid into the pipe body and sealing the pipe body. The portion with large-sized pores is capable of reducing the flow resistance to a condensed fluid to flow back, whereas the portion with small-size pores is capable of providing a relatively large capillary pressure for drawing the condensed fluid from the condensing section to the evaporating section of the heat pipe.

The invention provides a composition for preventing formation water lock, which comprises a fluorocarbon surfactant, a zwitterionic gemini surfactant and class III surfactants, wherein the class III surfactants are nonionic surfactants with a formula of CnH2n+1C6H5(OCmH2m)xOH or CnH2n+1(OCmH2m)xOH, n is an integer of 8-20, m is an integer of 1-4, and x is an integer of 4-30. The invention also provides application of the composition to preventing the formation water lock. By adopting the composition for preventing the formation water lock, the interfacial tension between water and gas and between oil and water can be greatly reduced, and the wetting angle of water to the mineral surface is increased; meanwhile, the composition also has a certain oil-drive effect, thereby being capable of reducing capillary pressure of driving water by gas (oil) and effectively preventing the formation water lock.

A heat pipe (10) includes a hollow pipe body (20) for receiving a working fluid therein and a screen mesh (30) disposed in the pipe body. The screen mesh includes at least two layers. One of the two layers is in the form of a planar layer (50) and the other is in the form of a wave layer (40). A plurality of flowing channels (48) is formed by the wave layer. The channels formed by the wave layer of the screen mesh are capable of reducing the flow resistance for the condensed fluid to flow back while pores in the screen mesh provide a relatively large capillary pressure for drawing the condensed fluid to flow back.

A flat heat pipe with hook capillary tissue includes a metal pipe, a capillary tissue and working fluid. The metal pipe is in a flat shape and formed by enclosing two opposite panels and two opposite sidewalls, and a hollow chamber is formed in the metal pipe. The capillary tissue is in the shape of a long strip, and includes having a hook formed at an end of the capillary tissue, and the capillary tissue is contained in the hollow chamber and attached onto one of the sidewalls and abutted between two sidewalls, and a working fluid is filled into the hollow chamber and adhered to the capillary tissue, so that the stability of fixing the capillary tissue into the metal pipe can be improved, and the retention quantity of the working fluid at an end of the pipe can be maintained.

Provided is a toner including: toner particles each containing at least a binder resin and a wax; and an external additive, in which surfaces of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 1.0 nm or more and 30.0 nm or less; and the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×10−3 N / m or more and 1.0×10−1 N / m or less:I=Pα / (A×B×106)  Eq. (1)where I represents the surface tension index (N / m) of the toner, Pα represents a capillary pressure (N / m2) of the toner for the 45-vol % aqueous solution of methanol, A represents a specific surface area (m2 / g) of the toner, and B represents a true density (g / cm3) of the toner.

The invention discloses a simulated liquid absorbing core for a heat uniformizing plate. The simulated liquid absorbing core is structurally characterized in that based on efficient transport structure of a plant leaf, a novel heat uniformizing plate in the simulated transport structure of the plant leaf is designed according to the point-to-surface transport principle of the plant leaf and the shortest path principle of transport. The heat uniformizing plate can be integrally designed with the liquid absorbing core, so that working medium can quickly enter a fractal passage under the action of capillary pressure, can quickly enter a polygonal microstructure tissue enclosed by the fractal passage and can reach the integral condensing surface of the heat uniformizing plate rapidly, and the working medium is quickly condensed into liquid state and can return to an evaporating end under the action of the capillary pressure, and one cycle is completed for preparation of the next evaporation. Meanwhile, due to the polygonal micropassage structure of a simulated vein structure, the liquid working medium is promoted to quickly flow to the periphery of a condensing end along the network passage of the liquid absorbing core, circulation of a working medium transport loop is accelerated, heat transfer efficiency is improved, and the simulated liquid absorbing core is small in size and applicable to precise electronic equipment.