17 results about "Vertical fracture" patented technology

The application discloses a hydraulic fracture translayer extension simulation method based on DDM-perturbation iteration coupling, belongs to the field of oil and gas field development engineering, and aims to solve the problem of insufficient simulation precision of asymmetric translayer extension of a horizontal well hydraulic fracture in stratified non-uniform rock mass. The method is based on a plane strain assumption, constructs a stratified rock mass model containing stratified fracture toughness, establishes a mechanical equation through a displacement discontinuity method (DDM), introduces a perturbation iteration method to dynamically adjust flow distribution, automatically adapts to new rock layer fracture toughness to update and expand criteria during translayer, and outputs vertical extension form and parameters. The method can be used for simulating translayer behavior of a horizontal well vertical fracture, improving calculation precision and efficiency, and providing a reliable tool for fracturing design of shale gas reservoirs and the like.

The application discloses a shale formation compressibility analysis method and device, and relates to the technical field of oil and gas exploration and development, wherein the method comprises the following steps: determining a brittleness index according to clay mineral content and total organic carbon content; determining a horizontal stress difference index according to an in-situ horizontal stress difference, a maximum horizontal stress difference when a horizontal fracture network is formed by fracturing, and a minimum horizontal stress difference; determining a vertical stress difference index according to an in-situ vertical stress difference, a maximum vertical stress difference when a vertical fracture network is formed by fracturing, and a minimum vertical stress difference; determining a natural fracture index according to a natural fracture density, a natural fracture width, and an angle between a natural fracture direction and a vertical direction of the maximum horizontal stress; determining a bedding index according to a bedding density and a bedding width; and determining a compressibility index according to the brittleness index, the horizontal stress difference index, the vertical stress difference index, the natural fracture index, and the bedding index. The application can improve the precision of shale formation compressibility analysis.

The invention provides a method for determining a crustal stress direction, and belongs to the field of geomechanics. The method comprises the following steps: collecting core data, logging data and geochemical data, identifying deposition characteristics, a sequence interface and single well lithology of a to-be-analyzed area, carrying out rock mechanical parameter logging interpretation, establishing a rock dynamic-static mechanical parameter conversion model, and determining single well rock mechanical parameter distribution of a target area; rock core observation and imaging logging interpretation are carried out through rock core data and logging data, the trend distribution rule of cracks in the vertical direction is determined, and the fast transverse wave orientation is further determined; and establishing a corresponding relation model between the fast transverse wave orientation and the trend distribution rule of the vertical crack, and establishing a ground stress direction discrimination standard to realize the determination of the ground stress direction. Compared with the prior art, the method for judging the direction of the maximum principal stress suitable for a complex structural area and a complex lithologic section is provided.

The application discloses a method for reconstructing a paleo-tectonic stress field based on vertical displacement of vertical fractures, and aims at solving the problem of low accuracy of the prior art in establishing a paleo-tectonic stress field. V V‑MAX V‑MIN V V V‑MAX V‑MIN V V‑MAX V‑MIN H V h H The method avoids the possible large human errors in the identification of typical structures and the matching with the theoretical model, and significantly improves the accuracy.​​​​​​​​​​​​​

The present invention belongs to the technical field of seismic inversion and provides a seismic inversion method and system for an equivalent medium with two groups of orthogonal vertical cracks. The method comprises: deriving an effective elastic stiffness matrix of an ORT weak anisotropic medium formed by the two groups of orthogonal vertical cracks, and obtaining a linearized PP wave reflection coefficient based on scattering theory and the perturbation stiffness matrix; then proposing a Bayesian azimuthal seismic inversion method for the effective elastic ORT anisotropic medium based on anisotropic perturbation of the PP wave reflection coefficient and an iterative reweighted least squares algorithm, solving a posterior probability distribution function of the model parameters, and finally achieving the characterization and estimation of the weakness parameters of the two groups of orthogonal vertical cracks.

This invention discloses a method for optimizing well layout parameters in a three-dimensional well network for fracturing in thick shale oil reservoirs. The optimization method includes: Step S1: Inputting the logging curve interpretation results of the pilot test well, and calculating the physical and geomechanical parameters of the target reservoir rock; Step S2: Calculating the reservoir quality, completion quality, and overall quality based on the physical and geomechanical parameters, and initially selecting the vertical landing sites for horizontal wells; Step S3: Establishing a reservoir fracturing geological model based on the physical and geomechanical parameters, building an unconventional oil and gas fracturing fracture propagation model, and simulating the vertical fracture height propagation of the initially selected vertical landing sites for horizontal wells; Step S4: Determining the optimal lateral well network density for each sub-layer based on single-well productivity; Step S5: Outputting the three-dimensional well network layout results. This method maximizes reservoir stimulation volume by drilling the fewest horizontal wells, meeting the needs of cost reduction and efficiency improvement.

The present specification relates to the technical field of oil exploration and development, and particularly discloses a fracture detection method and device, wherein the method comprises: acquiring a three-dimensional seismic coherence attribute volume of a target area; extracting a plurality of two-dimensional profiles from the three-dimensional seismic coherence attribute volume; calculating seismic coherence attribute reciprocals corresponding to each two-dimensional profile in the plurality of two-dimensional profiles; determining horizontal fracture indicator data corresponding to each two-dimensional profile according to the seismic coherence attribute reciprocals corresponding to each two-dimensional profile by using a preset horizontal determination rule; constructing a vertical determination rule based on the horizontal fracture indicator data corresponding to each two-dimensional profile; determining vertical fracture indicator data corresponding to each two-dimensional profile by using the vertical determination rule; and generating a fracture detection result corresponding to the three-dimensional seismic coherence attribute volume based on the vertical fracture indicator data corresponding to each two-dimensional profile. The above scheme can improve fracture detection accuracy.

The invention discloses a fracture surface density parameter prediction method and device based on array induction logging, and the method comprises the steps: obtaining at least three initial resistivity curves of a target well through an array induction mode; the at least three initial resistivity curves are preprocessed, at least three target resistivity curves are obtained, and data noise in the target resistivity curves is smaller than data noise in the initial resistivity curves; based on the at least three target resistivity curves, determining an initial crack surface feature vector of the target well, and performing normalization processing on the initial crack surface feature vector to obtain a target crack surface feature vector; and inputting the target fracture surface feature vector into the target prediction model for analysis to obtain a fracture surface density parameter of the target well, thereby solving the technical problem that the fracture surface density parameter is difficult to stably predict under the condition of a high-angle or vertical fracture.

The invention discloses a hydraulic fracture crossing expansion simulation method based on DDM-perturbation iterative coupling, belongs to the field of oil and gas field development engineering, and aims to solve the problem that the precision of asymmetric crossing expansion simulation of a horizontal well hydraulic fracture in a layered non-uniform rock mass is insufficient. The method comprises the following steps of: establishing a stratified rock mass model containing layered fracture toughness, establishing a mechanical equation through a displacement discontinuity method (DDM), introducing a disturbance iteration method to dynamically adjust flow distribution, automatically adapting to new rock stratum fracture toughness during stratum crossing to update an extension criterion, and outputting a vertical extension form and parameters; the method can be used for simulating the horizontal well vertical fracture crossing behavior, the calculation precision and efficiency are improved, and a reliable tool is provided for fracturing design of shale gas and other reservoirs.

The present application provides a kind of conglomerate reservoir fracture morphology prediction method and chart generation method, belong to the fracturing technical field of oil development.The present application constructs fracture propagation morphology model, establishes conglomerate reservoir fracture morphology prediction chart;According to conglomerate reservoir fracture morphology chart, determine whether the development form of hydraulic fracture is pressure post fracture development vertical fracture or horizontal fracture;For the area of vertical fracture development, collect the geological and mechanical parameters of the fracture that affects the vertical fracture development area and penetrates the layer;Fracture penetration expansion model considering reservoir and interlayer is constructed, and vertical fracture penetration chart is established;According to the collected geological and mechanical parameters of reservoir and interlayer, combined with vertical fracture penetration chart, determine whether hydraulic fracturing can penetrate interlayer.The fracture propagation morphology model constructed by the present application is more accurate, the fracture morphology prediction is more accurate, the selected fracturing operation mode is well matched with the geological characteristics of reservoir, the reservoir modification cost can be reduced, and the development benefit of oil field can be improved.

The present application belongs to the technical field of oil and gas geophysical exploration, and in particular to a seismic rock physics modeling method for describing the roughness degree of vertical fractures. The method comprises the following steps: S1: quantitative characterization of the rough fracture flexibility parameter; S2: establishment of a rock physics model containing a group of vertically oriented rough fracture media; S3: calculation of the rough fracture parameter; S4: revealing the mechanism of the response of the rough fracture density and roughness characteristics to the rough fracture flexibility parameter; S5: analysis of the overall elasticity and anisotropy response characteristics of the rock; S6: clarification of the elastic anisotropy response mechanism of the rough fracture-containing rock; S7: calculation of the azimuthal anisotropy response characteristics; and S8: determination of the azimuthal anisotropy response mechanism of the vertically oriented rough fractures in the rock. The present application provides an effective technical means for determining the seismic rock physics response mechanism of the rough fracture-containing rock and developing the well and seismic inversion method of the rough fracture parameter.

A method for storing high-pressure fluids as energy in a subterranean zone that prevents unwanted vertical fracture propagation and fluid loss irrespective of rock formation having varying pressures relative to the hydrostatic gradient. The method leverages rock properties, changes rock stress, permeability, hydraulic fracturing, fracture sealing materials and previously abandoned oil and gas zones.

The invention provides a shale gas layered development feasibility evaluation method, which is characterized by comprising the following steps of: finely describing each small layer in a target layer of a work area, further finely dividing each small layer in the longitudinal direction, calculating layered reserve abundance, and evaluating a reservoir type and whether a geological basis for layered development exists or not; in combination with a microearthquake monitoring result and fracturing construction parameter change, carrying out post-fracturing fracture network simulation after one-time well network implementation, and implementing a longitudinal fracture network transformation range; numerical simulation software is used for evaluating the reserve utilization conditions of the layers after the primary well pattern is implemented, and residual gas distribution of the small layers is implemented; according to the residual resource quantity of each small layer, in combination with economic evaluation estimation results corresponding to well drilling and gas test and production test investments, evaluating whether the resource quantity of the corresponding layer series during layered development can meet the requirements of economic and effective development or not; on the basis that resources reach the standard, the influence of longitudinal stress and interlayer stress difference on fracture height expansion is analyzed, and the layering development feasibility is further implemented. According to the method, the feasibility of shale gas layered development can be clearly evaluated, and efficient utilization of the shale gas reservoir and improvement of the recovery ratio are achieved.

The invention discloses a gas storage crack state determination method and related equipment, relates to the technical field of oil and gas reservoir development, and mainly aims to solve the problem that a more comprehensive gas storage dynamic sealing performance evaluation method is lacked at present. The method comprises the steps that feature data of a target gas storage are determined, and the feature data comprise near-wellbore zone wellbore reservoir effect data, near-wellbore pollution skin change data, vertical fracture conductivity data and reservoir physical property parameter change data; based on the characteristic data, evaluating the change of a crack characteristic curve, crack morphological parameters and crack conductivity of the target gas storage in multiple rounds of injection and production; and determining the fracture state of the gas storage based on the change of the fracture characteristic curve, the fracture morphological parameters and the fracture conductivity. The method is used for the gas storage fracture state determination process.

This application discloses a method for calculating the horizontal displacement curve of a vertical fracture, including: constructing a geomechanical model of the vertical fracture and calculating a corresponding mathematical model; setting different boundary conditions and constraints on the mathematical model and conducting numerical simulation of the tectonic stress field to obtain simulation results corresponding to each test; drawing the corresponding vertical displacement curve and horizontal displacement curve of the vertical fracture based on the simulation results corresponding to the different boundary conditions and constraints, and constructing a one-to-one correspondence between the vertical displacement DV and the horizontal displacement DH, thereby calculating the linear fitting equations of the major axis and minor axis; calculating the major axis and minor axis of the axis-aligned elliptical implicit function of the target vertical fracture based on the DV curve and major axis of the target vertical fracture, and calculating the DH curve of the target vertical fracture. Through this method, the accuracy of the calculation of the DH curve of the target vertical fracture can be improved.

The application discloses a calculation method of uplift bearing capacity of a shallow-buried rigid pile foundation, and comprises the following steps: S1, determining the specific weight gamma, internal friction angle phi and cohesive force c of the rock-soil body in the pile foundation buried depth range; S2, calculating the limit shear stress tau of the rock-soil body vertical fracture surface at different depths xz ; S3, calculating the shear stress of the rock-soil body at different depths; S4, calculating the shear force of the rock-soil body at different depths; and S5, adding the shear forces at different depths to obtain the foundation limit uplift bearing capacity T uk . According to the soil mechanics principle, the limit equilibrium theory of the rock-soil body is utilized, the shear strength of the rock-soil body under the uplift limit equilibrium state is derived from the basic physical and mechanical parameters of the rock-soil body, and then the uplift bearing capacity of the foundation is calculated from the shear strength. The uplift bearing capacity of the upper soil body is fully considered, which is favorable for accurately designing the foundation size and avoiding unnecessary waste.

The invention discloses a stiffness matrix characterization shale reflection coefficient approximation method containing a group of vertical fractures. A strong VTI shale background and weak HTI vertical fractures are considered, stiffness matrix characterization of a shale reservoir containing a group of vertical fractures is established, and phase velocity approximate analysis is deduced; based on the stiffness matrix representation, establishing polarization vector approximation of a shale reservoir containing a group of vertical fractures represented by a VTI medium background and fracture disturbance; based on the relationship between stress and strain, deriving an accurate elastic impedance tensor of a shale reservoir containing a group of vertical fractures, and constructing an accurate reflection coefficient suitable for any incident angle; a reflection coefficient equation is simplified on a weak contrast interface, and a reflection coefficient approximation formula, represented by a stiffness matrix, of a shale reservoir containing a group of vertical fractures is deduced. According to the method, the problems that a traditional method is difficult to apply to a shale reservoir with high anisotropy and the contribution degree of fracture seismic reflection is low are solved, the contribution degree of fractures to seismic reflection is improved, and a foundation is laid for fracture seismic stability prediction.