17 results about "Complex fracture" patented technology

The present application provides a shale gas complex fracture network characteristic parameter intelligent inversion method and system, the method adopts embedded discrete fracture model to establish the complex fracture network shale gas fracturing productivity model of shale reservoir; after determining the parameter value space to be inverted, the basic calculation examples are obtained based on random sampling, and parameter sensitivity analysis is carried out; the intelligent agent model is used to train the machine learning model with the basic calculation examples as the training samples, and the fracturing productivity prediction model is formed; the target example parameters meeting the error condition are optimized by using the set objective function based on the calculation results of the fracturing productivity prediction model; and then the target example parameters are brought into the complex fracture network shale gas fracturing productivity model to invert the target fracture network characteristic parameter results. The scheme can overcome the problems of time and cost consumption and limited applicability of the prior art, and can realize fast and reliable fitting by combining reservoir numerical simulation, intelligent machine learning model and optimization algorithm, and improve the shale gas complex fracture network characteristic parameter inversion efficiency.

The invention provides a fracture identification method and device for an ultra-deep carbonate reservoir in a subsurface mountainous area, and the method comprises the steps: sequentially carrying out the preprocessing of an original post-stack depth domain three-dimensional seismic body of a target work area, and obtaining a preprocessed seismic body; inputting the preprocessed seismic body into a three-dimensional convolutional neural network model to obtain an initial fault probability body; performing superposition display on the initial fault probability body and the original seismic section to form an initial superposition graph, constructing a learning sample set and a verification sample set, and determining the optimal iteration weight frequency; a final optimized neural network model is constructed according to the optimal iteration weight times, and a fault probability body is obtained through recalculation; and performing parameterization post-processing on the recalculated fault probability body to obtain a final fault probability body, and taking the final fault probability body and the final superimposed graph as a final fracture identification result. According to the scheme, the technical effect of improving the recognition precision of complex fractures, weak fractures and small-scale fractures is achieved.

This invention provides a method for inverting fractures in coal and rock fracturing based on the distribution of surface and end cleavage. The method includes: calculating key rock mechanical parameters and geostress parameters of deep coal and rock; establishing a simplified coal and rock mechanical model including surface and end cleavage, calculating the stress intensity factor at the fracture tip and the critical stress for fracture initiation, and obtaining the initiation criteria for I-II composite fractures; after fracture initiation, using the maximum energy release rate criterion to determine the propagation problem when hydraulic fractures meet natural fractures; combining the fracture propagation calculation method based on lightning simulation, using the similarity principle to consider reservoir geological parameters, geostress distribution, and fracturing construction parameters, and using circumferential stress and critical fracture stress to determine the propagation range of secondary fractures; introducing random functions and fractal probability exponents to characterize the random distribution characteristics of fracture propagation, simulating the propagation of complex fracture networks, and obtaining information on fracture morphology, length, and branch fracture density.

This invention discloses a method for predicting the production capacity of deep coal and rock gas considering complex fracture networks. First, the method establishes a fracture network topological tensor matrix based on fractal geometry and non-Euclidean topological manifolds. Second, it introduces a nanoscale confined multi-state desorption operator to construct a cross-scale gas release source term and integrates continuum damage mechanics and phase field theory to generate a full-tensor permeability evolution functional. Subsequently, a kinetic model is established to quantify the conductivity attenuation boundary caused by coal powder bridging. Combining the above parameters, a spatiotemporal fractional derivative is introduced to construct a comprehensive flow field control equation characterizing nonlocal anomalous diffusion of fluids. Finally, this equation is mapped to a hypergraph network system for global order reduction solution. This invention effectively eliminates the computational singularity of multiphysics rigid equation sets, achieving efficient and high-precision prediction of deep gas well production capacity under time series, providing reliable support for formulating scientific drainage and production systems.

The application provides a multistage hydraulic fracture propagation control method, comprising: obtaining the mechanical parameters of the rock mass in the tunneling area; constructing a crack mechanics model based on the mechanical parameters, calculating the critical crack initiation pressure and the optimal fracture azimuth angle, so as to determine the lowest fracturing fluid injection pressure and the corresponding drilling angle; based on the joint surface stress model and the crack propagation criterion, regulating the fracturing fluid injection pressure to guide the hydraulic fracture to propagate according to the preset propagation mode. The multistage hydraulic fracture propagation control method realizes the accurate regulation and control of multiple types of crack propagation modes, so as to achieve the controllable construction of the complex fracture network and overcome the blindness of the traditional experience design.

The present application relates to the technical field of fracturing aids, and is a temperature-controlled variable-density high-pressure-resistant proppant and a preparation method thereof.The raw materials of the temperature-controlled variable-density high-pressure-resistant proppant include a proppant, a surface modifier, a temperature-controlled polymer, an initiator and an organic solvent.The temperature-controlled variable-density high-pressure-resistant proppant is prepared by first modifying the surface of the proppant to obtain a modified proppant, then grafting and polymerizing the modified proppant with the temperature-controlled polymer, and finally post-treating the final product.The temperature-controlled variable-density high-pressure-resistant proppant can reduce the density under the response of the bottom-hole temperature, so that it is more easily transported to the deep part of a complex fracture network and uniformly laid, has a low breakage rate, can well support the fractures and promote the flow of oil and gas in the fractures.Meanwhile, the temperature-controlled variable-density high-pressure-resistant proppant still has high pressure resistance after swelling, so as to avoid being crushed to reduce the fracture width and block the seepage channel and reduce the fracture conductivity.

This invention discloses a locking bone plate, its preparation equipment, and a preparation method. The locking bone plate includes a bone plate body, a multi-directional micro-motion locking component, a gradient bioactive coating, a stress buffer structure, and a bone-inducing positioning component. The surface of the bone plate body has an anatomically conforming curved surface, with locking holes and micro-motion holes arranged alternately along its length, and a stress buffer structure in the middle. The multi-directional micro-motion locking component is assembled in the micro-motion holes, enabling multi-directional angle adjustment and axial micro-motion of the locking screws. The gradient bioactive coating fully covers the surface of the bone plate body and the walls of each hole, employing a three-layer structure. The bone-inducing positioning component is located on the bone side of the bone plate body that conforms to the bone, used to assist fracture reduction and induce bone cell growth. This invention achieves an organic combination of rigid fixation and multi-directional micro-motion, enhancing bioactivity and bone integration capabilities. It can adapt to complex fracture morphologies, reduce stress shielding, accelerate bone healing, and is safe to use and easy to assemble, possessing extremely high clinical application value.

A hydraulic pulse-type dissolvable staged acid fracturing sliding sleeve and a method for performing pulsed acid fracturing. The sliding sleeve includes an outer sleeve body (1) and a rotary valve assembly. The outer sleeve body (1) is provided with a flow-through hole (101). The rotary valve assembly includes a valve core (2) and a valve ball (13), and the valve ball (13) is capable of sealing a bore (203). A flow-guiding channel (206) and a flow-diverting channel (207) are formed between an outer wall of the valve core (2) and an inner wall of the outer sleeve body (1). The outer sleeve body (1) has a first position and a second position in an axial direction thereof. When the valve core (2) is in the first position, the outer wall of the valve core (2) seals the flow-through hole (101). An acid fracturing working fluid flowing through the flow-guiding channel (206) is capable of pushing the valve core (2) to move from the first position to the second position along the outer sleeve body (1), and pushing the valve core (2) to continuously rotate at the second position, such that the flow-diverting channel (207) is intermittently communicated with the flow-through hole (101), and the acid fracturing working fluid is ejected from the flow-through hole in the form of hydraulic pulses. The present application can excite hydraulic pulses of an appropriate frequency downhole, and can reduce energy attenuation and promote the creation of a complex fracture network in a formation.

The application discloses a reconstruction method and system for a complex fracture type water-containing oil and gas reservoir horizontal well, belongs to the field of fracturing reconstruction process technology of low-permeability tight oil and gas fields, and has the advantages that the development characteristics of a fracture zone are determined according to the sand body geological characteristics and seismic data of a horizontal well control area; the fracture type reservoir type corresponding to the position of each fracturing section in the direction of the horizontal well cylinder is determined according to the development characteristics of the fracture zone and the relative position relationship of the horizontal well; the differential fracturing process parameters of each fracturing section are determined according to the fracture type reservoir type and the effective fracture reconstruction range on both sides of the perforation points of the corresponding fracturing section, and fracturing reconstruction is carried out; the method is designed by avoiding the reconstruction method of the fracture zone, the water-containing layer of the fracture zone and the fracture-induced fracture is avoided, the probability of water outflow of the horizontal well is reduced, and the implementation effect of the segmented fracturing reconstruction of the water-containing oil and gas reservoir horizontal well is improved.

The application provides a network fracture body flow conductivity anisotropy testing device and method, the device comprises a fluid injection and control module, a rock sample special-shaped clamping and flow guiding module, a special-shaped sealing rubber sleeve and a fluid output and metering module; the fluid injection and control module comprises a gas injection module and a liquid injection module, the gas injection module simulates a reservoir gas source; the liquid injection module simulates a stress state under reservoir conditions; the special-shaped sealing rubber sleeve is used for placing a rock sample and comprises a rock sample placement cavity; the fluid output and metering module is a dry output gas source, measures an outlet pressure value and a gas flow value, and forms a data record and a flow curve in a computer. The testing device can simulate the overall flow conductivity of a network fracture body under complex fracture morphology and stress conditions formed after reservoir fracturing reconstruction, evaluate the anisotropy degree of the network fracture body flow conductivity, and provide experimental data for reservoir reconstruction fracturing parameter design and post-fracturing production system optimization.

The present application relates to a kind of coalbed gas reservoir fracturing method and its application, belong to coalbed gas mining technical field.The fracturing method includes the following steps: sequentially injecting pretreatment fluid, preflush, sand-carrying fluid and displacement fluid;The preflush includes first combination fluid and second combination fluid;The first combination fluid includes high-viscosity fracturing fluid, low-viscosity fracturing fluid sequentially injected in front and back, wherein high-viscosity fracturing fluid creates main fracture, the low-viscosity fracturing fluid segment type sand plug coal rock microcrack and cleat and expands fracture network;The second combination fluid includes high-viscosity fracturing fluid, medium-viscosity fracturing fluid sequentially injected in front and back, wherein high-viscosity fracturing fluid creates long fracture, the medium-viscosity fracturing fluid continuously sand-carrying forms netted support fracture.The method of the present application can form main fracture+complex fracture network by fracturing, improve fracture complexity, increase fracture sweep range, improve fracture conductivity, thereby improve the gas production of coal seam.

The present application provides a shale reservoir fracture prediction method and system based on three-dimensional full waveform inversion, and a medium, relating to the technical field of data analysis, comprising: arranging a multi-channel seismic exploration instrument in a shale reservoir area, collecting full waveform seismic data, including longitudinal waves, transverse waves and reflected waves; performing three-dimensional full waveform inversion based on logging data and geological structure maps, and full waveform seismic data to generate a shale reservoir attribute model; constructing a multi-scale inversion strategy, performing fracture sensitivity analysis and fracture morphology dynamic prediction to obtain reservoir fracture distribution characteristics and reservoir fracture morphology characteristics; performing discrete fracture point connection and fracture network reconstruction to construct a reservoir three-dimensional fracture network model and perform fracture prediction visual display. The present application solves the technical problem that the prior art can only provide inference based on limited data, lacks comprehensive capture of complex fracture networks, and cannot comprehensively and accurately describe the distribution and morphology of fractures, affecting reservoir analysis and production decision-making.

The present application relates to the technical field of oil and gas drilling engineering, and specifically discloses a multi-field coupling complex fractured formation fracture width distribution inversion method, based on the theory of porous elasticity, a drilling fluid loss model considering fluid-solid coupling effect is constructed, a roughness correction factor is introduced to correct the traditional cubic law, and the application of Darcy's law in the matrix is improved, a drilling fluid loss mathematical model coupled with the matrix and the fracture is established, through numerical simulation, the influence law of key parameters such as fluid viscosity, pressure difference and fracture width on drilling fluid loss is obtained, and on this basis, a fracture width multivariate linear regression inversion equation with fluid viscosity, pressure difference and cumulative loss as independent variables is established, the inversion equation has high prediction accuracy and practicability, can be used for quickly and accurately inverting the fracture width on site, and provides theoretical and technical support for the understanding of the loss mechanism of multi-scale fractured formation and the optimization of leakage prevention and treatment.

The application provides a proppant migration state prediction method and system based on images, and relates to the technical field of oil and gas development.The method comprises the following steps: processing and predicting a real-time image sequence currently collected by using a prediction neural network model to obtain current placement form prediction data of the proppant in a complex fracture; obtaining a regulation instruction based on the current placement form prediction data, and sending the regulation instruction to a field fracturing construction control unit to close-loop control the proppant migration process.The application realizes accurate prediction and closed-loop control of the proppant migration state through downhole image collection, preprocessing, segmentation correction, multi-source data fusion modeling and real-time prediction and regulation.

The application provides a construction parameter optimization method for complex in-fracture proppant migration and placement, and belongs to the technical field of hydraulic fracturing in oil and gas field development engineering, and the method comprises the following steps: a complex fracture propagation model considering natural fracture interference is established, global coupling iteration is solved, and fracture parameters are obtained; a proppant migration experiment is carried out, and a sand-carrying fluid diversion formula is fitted; a proppant migration model considering main and secondary fracture diversion is established, the proppant distribution state is solved and updated; the complex fracture propagation model and the proppant migration model are coupled to establish a proppant migration and placement model in a complex fracture; a proppant efficiency index (PEI) is constructed based on the simulation results of the coupled model, the distribution effect of the proppant under different construction parameters is evaluated; the construction parameters are input, the PEI value is calculated based on the proppant distribution state, and the construction parameters are optimized. The application realizes the optimization of the construction parameters by predicting the proppant distribution state in the complex fracture network and evaluating the effect through the PEI index.