16 results about "Darcy" patented technology

The invention relates to the technical field of petroleum and natural gas drilling engineering, and particularly discloses a multi-field coupled complex fractured formation fracture width distribution inversion method, which is characterized in that a drilling fluid leakage model considering a fluid-solid coupling effect is constructed based on a porous elastic mechanics theory, and a roughness correction factor is introduced to correct a traditional cubic law; the application of the Darcy law in the matrix is perfected, a matrix and crack coupled drilling fluid leakage mathematical model is established, the influence rule of key parameters such as fluid viscosity, pressure difference and crack width on the drilling fluid leakage amount is obtained through numerical simulation, and on the basis, the drilling fluid leakage amount is calculated. According to the method, the crack width multiple linear regression inversion equation with the fluid viscosity, the pressure difference and the accumulated leakage as independent variables is established, the inversion equation has high prediction precision and practicability and can be used for rapidly and accurately inversing the crack width on site, and theoretical and technical supports are provided for multi-scale fractured formation leakage mechanism understanding and leakage prevention and control optimization.

The present application relates to oil and gas field development technology, disclose a kind of heavy oil reservoir hot water drive limit well spacing determination method. Including the following steps: S1, the starting pressure gradient corresponding to different temperature is obtained by percolation experiment test;S2, according to the starting pressure gradient corresponding to different temperature, determine the inflection point temperature of starting pressure gradient curve;S3, based on the inflection point temperature of pressure gradient curve, the percolation area between injection well and production well is divided;S4, based on the percolation area divided, the percolation resistance R of darcy percolation area between injection well and production well is calculated d ;S5, based on R d The pressure drop ΔP of darcy percolation area between injection well and production well is calculated d ;S6, based on ΔP d The length l of non-darcy percolation area between injection well and production well is calculated nd ;S7, based on l nd Determine the limit well spacing L of heavy oil reservoir hot water drive. The determination method can guide the formulation of heavy oil reservoir hot water drive development plan, improve development effect.

The present application relates to the technical field of seepage mechanics, and particularly relates to a conical sealing surface leakage rate calculation method based on Darcy's law, comprising the following steps: a W-M function is used to simulate the random topography of the workpiece surface at a microscale, and a normalization method is used to generate surface point cloud data meeting roughness requirements; according to the surface point cloud data, a contact mechanics model is used to solve the change law between the contact state and the external load, and according to the Hertz contact theory, the contact between the rough surfaces is reconstructed as the contact between a rigid plane and a flexible rough surface; the surface is discretized into a three-dimensional grid model, the effective porosity is screened and calculated by using the connected domain discrimination method; a micro-leakage rate calculation method for the conical sealing surface in the flared pipe joint is obtained based on the effective porosity and the seepage mechanics theory algorithm; the leakage rate of the conical sealing interface is calculated, and the sealing performance of the interface is quantitatively evaluated. The present application improves the comprehensiveness and accuracy of the sealing performance evaluation.

The application provides a shale gas accumulation type determination method, which comprises the following steps: according to the throat radius of connected pores in the shale sample in the bedding direction, the connected pores are classified; according to the volume of each type of connected pores, the accumulation type of the shale gas is determined; wherein, the types of the connected pores include Darcy diffusion type connected pores, slip flow type connected pores, Fick diffusion type connected pores and Knudsen diffusion type connected pores. The determination method can more accurately determine the accumulation type of the shale gas.

The application discloses a metamaterial flow uniformity maintaining device, a preparation process and application. The metamaterial flow uniformity maintaining device comprises a transition part, a first maintaining part and a second maintaining part. The transition part is in an arc shape, and the radius satisfies R1 < r < R2. The transition part, the first maintaining part and the second maintaining part are all made of a metamaterial. In the embodiments of the application, a two-dimensional or three-dimensional flow uniformity maintaining device conforming to a condition formula for maintaining the flow uniformity in a variable channel obtained according to the Darcy law and corresponding boundary conditions is constructed. The device has sufficient theoretical basis and high reliability. The flow uniformity maintaining device can maintain the flow uniformity of fluid after the fluid passes through a contraction or expansion pipeline, reduces the pressure drop and resistance of the fluid in the flow process, and further guarantees the stability and uniformity of the fluid in the variable channel flow.

This invention discloses a method for calculating the pressure of different zones in shale oil and gas reservoirs based on fluid exchange, relating to the field of oil and gas development. Addressing the difficulty in calculating the pressure within the three media of the matrix zone, weakly stimulated zone, and strongly stimulated zone during shale oil and gas reservoir development, this invention proposes a three-zone average pressure coupling calculation method based on Darcy's law and mass balance. This method fully considers the fluid exchange between the three zones of the shale oil and gas reservoir, utilizing the pressure difference driving mechanism of Darcy's law to directly link pressure changes with fluid flow. It directly couples the pressure of the three zones through fluid exchange, clearly expressing the interaction between each zone, accurately reflecting the influence of pressure gradients and flow fluxes between different areas. It achieves high computational efficiency while ensuring accuracy, not only calculating static pressure distribution but also dynamically tracking pressure changes over time, optimizing oil and gas well production strategies, and improving reservoir development efficiency.

This invention provides a method for predicting the production capacity of electrically heated cold-drive heavy oil reservoirs using wellbore coupling, belonging to the field of oil and gas field development engineering technology. The method includes acquiring basic reservoir parameters and electrical heating parameters; solving for the reservoir temperature distribution at the current time step based on energy conservation; dividing isothermal zones into different temperature zones based on temperature; tracking the cold-drive front position using the Buckley-Leverett method to determine the friction saturation and production end saturation, and calculating the heavy oil production; combining the injection well pressure and friction saturation, solving for the injection-production pressure difference based on Darcy's law to obtain the bottomhole flowing pressure of the production well; inputting the bottomhole flowing pressure and temperature into the wellbore pressure drop model to calculate the wellbore pressure profile and temperature profile; iteratively updating until the end of the production cycle, and outputting the production capacity prediction result. This invention solves the problems of inaccurate predictions caused by existing models' single scenario, neglect of thermal-fluid coupling, and lack of wellbore coupling, and can accurately predict the production capacity of electrically heated assisted cold-drive heavy oil reservoirs.

The invention discloses a productivity evaluation method for a small-pressure-difference high-yield gas well, and belongs to the technical field of gas well development, correction coefficients beta corresponding to different alpha coefficients are calculated, and correction coefficient beta charts corresponding to the different alpha coefficients are drawn; the method comprises the following steps: collecting typical gas well productivity well test data, fitting to obtain a Darcy seepage item coefficient A and a non-Darcy seepage item coefficient B, and calculating open flow capacity and a stable empirical number alpha coefficient of a gas well; calculating gas production rates corresponding to different gamma on the basis of formation pressures of gas wells with different stable empirical number alpha coefficients, a Darcy seepage item coefficient A in a pressure square form and a non-Darcy seepage item coefficient B in a gas well pressure form, adding data into the chart, and drawing a'one-point method 'productivity evaluation comprehensive correction chart; and calculating gamma according to the oil testing yield, the formation pressure and the flowing bottomhole pressure of the well, inquiring a correction coefficient beta in the comprehensive correction chart, substituting the correction coefficient beta into a one-point method calculation formula containing the correction coefficient beta, and evaluating the productivity of the gas well.

This invention provides a method and system for calculating inter-well formation pressure after a shale gas platform is put into production. The method includes: calculating the recovery degree R based on EUR and the current cumulative gas production Gp; and calculating the average formation pressure P under the original conditions. i Gas deviation factor Z under original conditions i EUR and Gp are used to calculate P1; a ~R diagram is plotted and a binomial fit is performed to obtain the deviation coefficient σ; P'2 is the measured formation pressure, P'1 is the formation static pressure, Z'1 is the gas deviation factor corresponding to P'1, and Z'2 is the gas deviation factor corresponding to P'2; P2 is calculated based on σ and P1; in the later stage of production, shale gas wells reach the boundary control flow stage, utilizing the formation pressure p at the gas supply boundary. e The Darcy steady-state flow formula for radial flow in a fracturing plane describes the formation pressure p(r) at any distance from the well in the reservoir. The system described above can implement this method. This invention can calculate the formation pressure drop after production commences.

The invention relates to a method for determining a relative permeability curve of ternary composite oil displacement, which comprises the following steps of: establishing a numerical simulation model by using rock core experimental data, and setting a relative permeability curve as uncertain parameter fitting rock core displacement data so as to invert the relative permeability curve of ternary composite oil displacement; the relative permeability curve determined by the method is not limited by the type of the ternary composite solution and is also suitable for a Darcy seepage equation in numerical simulation software, the relative permeability curve is applied to research work in the aspects of reservoir engineering parameter calculation, dynamic analysis, numerical simulation and the like, the accuracy of a research result can be improved, and the research efficiency is improved. The seepage characteristics in the tertiary oil recovery process can be further elaborated, and important technical support is provided for formulating a reasonable working system, optimizing a development scheme and improving the recovery efficiency of tertiary oil recovery.

The application discloses a rock specific surface evaluation method based on gas well dynamic data, and comprises the following steps: S1, collecting and arranging gas well static data and gas well dynamic data; S2, using a Blasingame modern production harmonic decline graph board curve to extract a part meeting the Darcy seepage law, and recording a time period as [t0, t1]; S3, calculating an equivalent gas discharge radius and a gas well skin coefficient; selecting a subinterval [t'0, t'1], using an exponential decline model to carry out fitting, and calculating a decline rate; S4, establishing a rock specific surface model, and obtaining the rock specific surface by using the rock specific surface model. The application establishes a quantitative model of the rock specific surface, effectively avoids the limitation of a laboratory overburden condition; meanwhile, by means of well logging interpretation results and seepage mechanics theory, the rock specific surface calculation scale is expanded from a core scale to a large scale of a well logging interpretation series detection radius and a well control range, the rock specific surface model can reduce core analysis experiments, can reduce gas reservoir development cost from the economic aspect, and can improve gas reservoir development benefit.

This invention discloses a method for calculating the production rate of fractured wells in heterogeneous tight oil reservoirs considering the initiation pressure gradient. First, based on the closed boundary point source function, a multi-scale seepage model of matrix seepage in heterogeneous tight oil reservoirs is established using Green's formula and Newman integral. Then, according to the skin principle, a negative skin coefficient is introduced to describe the influence of the fracture network stimulation zone on seepage, resulting in a flow characterization model of the fracture network stimulation zone. Next, the main fracture flow equation is established, and the pressure drop equation of a single discrete fracture unit is described using Darcy's law. The pressure drop characterization model from any discrete unit to the horizontal wellbore is calculated using the pressure drop superposition principle, resulting in the main fracture flow characterization model. Finally, a production rate calculation model for fractured wells in heterogeneous tight oil reservoirs is coupled and established. The steady-state production processes of fracture micro-segments within each small time interval are superimposed, and a heterogeneity coefficient is established based on the skin principle, resulting in a production rate calculation model for fractured wells in heterogeneous tight oil reservoirs under variable production conditions. This method enables rapid and effective, precise prediction of production rates.

The present application provides a kind of shale oil microscale pore nonlinear flow characteristic characterization method, comprising: step 1, the micro-pore structure distribution of shale core is measured;Step 2, the adsorption capacity of shale core to shale oil fluid is measured;Step 3, the micro-pore flow model considering Darcy flow+non-Darcy flow+boundary layer thickness is used, the flow value of shale oil in different size shale pore changes with driving pressure difference is calculated;Step 4, the nonlinear relationship curve of displacement pressure gradient and flow is drawn using the calculation result;Step 5, the nonlinear characteristic parameter of shale oil flowing in different pores of shale is determined according to the nonlinear relationship curve of displacement pressure gradient and flow.The shale oil microscale pore nonlinear flow characteristic characterization method accurately describes the nonlinear flow characteristics of shale oil when passing through the microscale pore space of shale, and provides a reliable theoretical basis for accurately analyzing the nonlinear seepage mechanism of shale oil.

The invention provides a gas reservoir flowing substance equilibrium reserve calculation method, and relates to the technical field of gas reservoir reserve calculation. The method comprises the steps that basic parameters of a constant-volume gas drive gas reservoir and dynamic data of well bottom flowing pressure actually measured in the stable production stage of a gas well are sorted and smoothed; secondly, initial flowing bottomhole pressure and a pressure square difference initial value are determined, and it is assumed that the pressure square difference is constant; then, the average formation pressure, the gas deviation coefficient and the gas isothermal compression coefficient in the gas well stable production process are circularly calculated; then constructing a gas reservoir flowing substance balance equation considering the non-Darcy effect, and calculating dynamic data of variables X and Y; adjusting a pressure square difference value through iteration, and performing linear fitting on the X and Y scatter points until the longitudinal axis intercept of a linear function approaches zero, so as to determine a straight slope; and finally calculating the single well control reserves according to the slope and the basic parameters. According to the method, the limitation of Darcy seepage hypothesis is overcome, and accurate reserve evaluation based on whole-process data is realized.

The application relates to the technical field of water conservancy and hydropower engineering, and discloses a dam foundation covering layer nonlinear seepage fine calculation method and system, which aims to solve the problem of poor accuracy and fineness of the existing method, and mainly comprises the following steps: constructing a seepage wall geometric model containing defects based on field drilling data and dividing the grid; based on the physical property parameters of the covering layer soil, the Darcy seepage coefficient and the Forchheimer seepage coefficient under the Darcy-Forchheimer model are calculated by using the Ergun formula; boundary conditions, fluid parameters and solution control parameters are configured, and the nonlinear seepage characteristic parameters of the covering layer soil and the seepage wall defects are specified to construct a fine analysis model; the seepage field numerical calculation is carried out based on the RANS equation and the Darcy-Forchheimer model by using a finite volume method solver; and the calculation results are extracted to obtain the nonlinear seepage field distribution containing the covering layer soil and the seepage wall defects. The application improves the accuracy and fineness of the dam foundation seepage calculation containing the seepage wall, and is suitable for two-dimensional seepage analysis or three-dimensional seepage analysis.

The present application relates to solid waste incineration working condition adjustment technical field, especially, it relates to a kind of solid waste incineration working condition intelligent sensing and self-adapting adjustment method, realize the direct quantitative sensing of combustion state in furnace, based on Darcy law calculation layer equivalent permeability, based on Stefan-Boltzmann law calculation local effective heat release flux, can reflect the air permeability and combustion intensity of layer in real time, fundamentally solve the problem of traditional parameter lag.Equivalent heat-pneumatic impedance factor is proposed as comprehensive working condition evaluation index, the coupling relationship of heat release and gas flow is uniformly represented, a scientific quantitative basis is provided for control decision, and the control precision is significantly improved.A double-layer control architecture of adaptive fuzzy neural network combined model predictive control is constructed, the former realizes the multivariate coordinated regulation of primary air, secondary air, feeding and speed of grate, and the latter realizes the precise predictive control of auxiliary burner, and the working condition stability and adjustment speed are greatly improved by the cooperation of the two.