1132 results about "Stress field" patented technology

Reinforced, laminated, impregnated, and materials with composite properties as cross linked polyvinyl alcohol hydrogel structures in bulk or cellular matrix forms that can take essentially any physical shape, or can have essentially any size, degree of porosity and surface texture. They have a wide range of physical properties, unusual and unique combinations of physical properties and unique responses to stress fields, which allows for their use in many end use applications.

A method and apparatus for orchestrating multiple fractures at multiple well locations in a region by flowing well treatment fluid from a centralized well treatment fluid center is disclosed that includes the steps of configuring a well treatment fluid center for fracturing multiple wells, inducing a fracture at a first well location, measuring effects of stress fields from the first fracture, determining a time delay based in part upon the measured stress effects, inducing a second fracture after the time delay at a second location based upon the measured effects, and measuring the stress effects of stress fields from the second fracture. Sensors disposed about the region are adapted to output effects of the stress fields. Location and orientation of subsequent fractures is based on the combined stress effects of the stress fields as a result of the prior fractures which provides for optimal region development.

A method and apparatus for use in estimating stress fields in a geological formation are disclosed. The method includes ascertaining a perturbation of stress in the triaxial stress state in a reservoir and in a surrounding rock mass over time; and determining the change in a seismic attribute resulting from the perturbation in the stress. The apparatus includes a program storage medium encoded with instructions that, when executed by a computing device, perform such a method or a computing system programmed to perform such a method.

The invention discloses a non-planar network fracturing construction control method for a fractured reservoir, which includes the step: firstly, performing pre-fracturing evaluation by (1) obtaining the intrinsic fracture development degree and directions according to FMI (formation micro-scanner image) logging and conventional logging data, (2) determining man-made fracture directions, (3) judging the angle relation between man-made fractures and intrinsic fractures, and (4) judging the non-planar network fracturing formation adequacy; secondly, establishing a stress field inversion constrained optimization model by utilizing a numerical value inversion method combining multi-well constrained optimization and finite elements so as to obtain numerical simulation of three-dimensional geostress states and rock mechanical parameters of a fractured reservoir area; thirdly, selecting corresponding construction parameters, and fracturing strata so as to force the intrinsic fractures and holes to open as large as possible; and fourthly, according to the opened equivalent number and openness of the intrinsic fractures explained by test fracturing, selecting grain sizes and use amount of propping agents matched with the intrinsic fractures or the holes, and leading fracturing fluid carrying the propping agents to enter the intrinsic fractures or the holes.

The present invention relates generally to methods for designing and optimizing the number, placement, and size of fractures in a subterranean formation and more particularly to methods that account for stress interference from other fractures when designing and optimizing the number, placement, and size of fractures in the subterranean formation. The present invention optimizes the number, placement and size of fractures in a subterranean formation. The present invention determines one or more geomechanical stresses induced by each fracture based on the dimensions and location of each fracture, including surface deformations caused by each fracture. The present invention determines a maximum number of fractures and a predicted stress field based on the geomechanical stresses induced by each of the fractures.

In an exemplary embodiment, a method and system is disclosed for developing a subterranean geomechanics model of a complex geological environment. The method can include estimating a pore pressure field, a stress field, a geomechanics property field, and a geological structure field from a geological concept model; geostatistically interpolating vectors and tensors from the estimated fields; and combining the results from the estimated fields and the geostatistically interpolated vectors and tensors to derive a geostatistical geomechanical model of the geological environment.

The invention relates to an optimum design method for staged fracturing perforation cluster parameters of a horizontal well of a shale reservoir. The optimum design method includes the following steps of S1, selecting high-fracture-performance fracturing well sections; S2, building a mathematical model for hydrofracture fracture progressing, analyzing an induction stress field model for fracture extension, and analyzing a fracture diverting mechanism; S3, analyzing extending conditions of main fractures, and selecting cluster distances capable of allowing the main fractures to evenly extend forwards; S4, analyzing change conditions of stress fields around the main fractures, selecting the perforation cluster distances with the horizontal principal stress ratios smaller than 1.3, and determining the optimal perforation cluster distances in cooperation with the step S3; S5, further improving the complexity of the fractures through an alternate fracturing principle, and setting the perforation density of perforation clusters in the middle to range from 10 to 16 per m and the perforation density of perforation clusters in the two sides to be larger than 16 per m. By means of the optimum design method, the perforation cluster distances can be optimized, largest fracture transforming sizes can be obtained, the practical effect of reservoir transforming can be improved, and high construction cost and the poor fracturing effect which are caused by aimlessly setting the perforation cluster distances can be avoided.

The present invention relates generally to methods for designing and optimizing the number, placement, and size of fractures in a subterranean formation and more particularly to methods that account for stress interference from other fractures when designing and optimizing the number, placement, and size of fractures in the subterranean formation. The present invention optimizes the number, placement and size of fractures in a subterranean formation. The present invention determinines one or more geomechanical stresses induced by each fracture based on the dimensions and location of each fracture. The present invention determinines a maximum number of fractures and a predicted stress field based on the geomechanical stresses induced by each of the fractures

The invention discloses a multi-field coupling true triaxial test system and an experiment method implemented by the same. The multi-field coupling true triaxial test system is characterized by comprising a true triaxial double-cavity pressure chamber (1), an axial loading system (2), a confining pressure / back pressure loading system (3), a temperature control system (4), a permeation control system (5), a gas loading system (6), a bending element experiment system (7) and a computer (8). The multi-field coupling true triaxial test system and the experiment method have the advantages that stress fields and seepage fields are controlled, and accordingly simulation research can be carried out on seepage anisotropy of rock and soil mass; influence of environmental factors on freezing nucleusor frozen soil samples can be simulated under the effects of temperature fields, the seepage fields and the stress fields; research can be carried out on the physical and mechanical properties of unsaturated frozen soil under the effects of the temperature fields and the stress fields; simulation research can be carried out on change of the physical and earth properties of sediments in generationand decomposition procedures of natural hydrates under multi-field coupling conditions, and simulation research can be carried out on mutual displacement effects between hydrate gas in the sediments and underground water; simulation research can be carried out on the physical and mechanical properties of unsaturated soil under the multi-field coupling conditions.

The invention discloses a numerical simulation method for a selective laser melting process. The method comprises a first step of establishment of a finite element model of additive manufacturing process simulation; a second step of meshing on the finite element model of the additive manufacturing process, wherein full-hexahedron meshing is adopted; a third step of definition of printing powder material properties and thermal physical performance parameters which must be determined for temperature field analysis in the additive manufacturing process; a fourth step of loading of a control equation of a mobile heat source; and a fifth step of analysis of thermal stress field and total deformation changes in the additive manufacturing process and after sintering is finished. Through the numerical simulation method for the selective laser melting process, printing parameters can be optimized, and warping and deformation of parts can be prevented; and the method provides effective guidancefor supporting structural design and a printing strategy (speed and direction), lowering the rejection rate and realizing ''success at a time''.

The invention provides a low permeability gas reservoir turning repeated fracturing technological method. The specific technological method comprises the following steps of gas well initial fracturing failure or low-efficiency reason analyzing, reservoir stratum evaluating conducted before turning repeated fracturing, turning repeated fracturing well selection and stratum selection decision making, rock mechanical parameter and ground stress testing, turning repeated fracturing ground stress field changing simulating, fracture geometrical parameter and flow conductivity optimizing, turning repeated fracturing technology optimizing, fracturing liquid and turning agent studying, repeated fracturing constructing and evaluating conducted after repeated fracturing. The well selection and stratum selection decision making and residual gas detecting serve as verification systems of each other, fracturing design and fracture detecting serve as verification systems of each other, and a novel fracture turning agent is used in the low permeability gas reservoir turning repeated fracturing technological method. The integrated design of the low permeability gas reservoir turning repeated fracturing is achieved, and the low permeability gas reservoir turning repeated fracturing technological method has the advantages that the design links are macroscopically integrated, local innovation is achieved, linkage is close, mutual verification is achieved, the design is advanced, and the technological advantage is obvious.

The invention discloses a health-monitoring system of a distributed sensing fiber tunnel, comprising sensing fibers arranged in a tunnel and a processing system for collecting and processing the data of the sensing fibers which are distributed in the secondary lining concrete of the tunnel. The invention reasonably designs the health-monitoring detection network of the fibers, utilizes a fiber air-blowing technology and a tunnel vacuum aided grouting technology to embed the distributed sensing fibers in the secondary lining concrete and paste the distributed sensing fibers on the surface of the tunnel structure in a mode of reserving pre-buried grooves. The invention acquires an initial stress field by embedding sensing elements in the construction period and realizes the online, dynamic and real-time health monitoring of the tunnel structure.

The invention discloses a device for testing the durability of a water pressure resistant grouted rock, which comprises a pressure chamber, a control cabinet, heating equipment, pressurizing equipment, measuring equipment and accessory equipment, wherein the heating equipment can supply a stable heat source for the pressure chamber; the pressurizing equipment can provide confining pressure and osmotic pressure for the pressure chamber; the pressure chamber can apply an axial pressure by means of a universal test, is corrosion resistant and can realize annular and vertical penetration tests of three kinds of standard samples of different dimensions at different temperatures and pressures; the measuring equipment can realize accurate measurement of temperature, pressure and flow rate; and the control cabinet can realize the accurate control of pressure and temperature. The device can be used for indoor researches on the durability of tunnel water pressure resistant grouted rock or dam impervious curtain in an environment of high-water-pressure and corrosive environment, and at the same time, realizes the researches on the change rule of the permeability of a rock sample under the coupled actions of a temperature field, a seepage field, a stress field and a chemical field.

The invention relates to the field of laser processing manufacture, in particular to a laser shock precision forming method and a device. The device comprises a laser, an outer light path system, a laser shock head system A, a flying optical processing system with a laser shock head system B, a test sample system, a detection feedback system, a multi-axis link machine tool and a tool fixture system, a central control processor and a control system. A laser beam emitted by the laser is split by the outer light path system and are respectively transmitted to the front and the rear surfaces of a workpiece to subject the front and the rear surfaces of the double-sided workpiece with an energy absorption layer and a confinement layer to laser-induced shock wave. According to the requirements of the shape and the formation rule of a plate material, the double-sided laser shock head can execute simultaneous and non-simultaneous shock, counter shock, staggered shock, shocks with same and different energy, etc., so that the plate material is formed by generating a certain plastic deformation and a stress field distribution and that a certain residual stress is formed on the surface of the plate material. The method can achieve accurate quantitative formation, good repeatability and high forming efficiency, and can easily achieve automatic production.

The invention discloses a test method of karst water burst when tunneling, comprising the following steps of: preparing materials; filling materials; embedding elements; embedding a water tank; injecting water and monitoring, tunneling and monitoring, etc. The invention further discloses a monitor device used for the test method of the karst water burst when tunneling, comprising a module frame fixed on a base, a preset water tank, a water pressure loading mechanism, a stress field monitoring mechanism, a deformation field monitoring mechanism, a temperature field monitoring mechanism, a seepage field monitoring mechanism, an acoustic emission field monitoring mechanism, a module surface displacement deformation observing mechanism, a module deformation and water burst observing mechanismin tunnels after tunneling, a fiber demodulation device and a computer. The invention simultaneously can research the change regularity of premonitory multi field information which induces the water burst when tunneling at different water body containing positions and under different water pressure conditions, has wide application, high reliability, abundant collecting data, high test precision, etc.

The invention discloses a visual model testing device and method for simulating water gushing in a tunnel. The device comprises a model test box, a water tank, a high-pressure water pump, a flow meter, a runoff flow and filling collecting device, a digital photographing non-contact measuring system, an osmotic pressure monitoring system, a fiber grating displacement monitoring system and the like. The testing device is characterized in that the catastrophe evolution process of water gushing in the tunnel is simulated, and anti-gushing rock mass crack growth and water gushing channel formation during water gushing can be directly observed. The device can quantitatively research water gushing behavior of the tunnel under different water pressure, different lithological characters and different thicknesses of anti-gushing rock masses, acquire coupling information of multiple fields such as stress fields, displacement fields, seepage fields and the like during water gushing of the tunnel, determine formation processes and forms of water gushing channels under the effect of different factors, disclose mechanical characteristics and evolution laws in anti-gushing rock mass structure progressive failure processes and provide an effective basis for the tunnel water gushing disaster incoming criterion and the minimum safe thickness analysis method.

The invention discloses a visual-model testing apparatus and testing method for seepage-stress-coupled internal piping penetration. The testing apparatus is composed of four parts, i.e., a variable-head control and liquid circulation system, a vertical loading and penetration system, a laser control system and an image acquisition system and can carry out experimental study on internal piping penetration of non-steady seepage under the conditions of different stresses, different contents of fines, different grading and the like and research on the characteristics of particle loss and deformation and fracture in the process of seepage. The invention also provides a visual testing method for seepage-stress-coupled simulated erosion-type internal piping. According to the method, head difference is applied to a piping soil sample in a stress field in the vertical loading and penetration system in virtue of the variable-head control and liquid circulation system, so a seepage-erosion-stress three-field coupled internal piping test is realized. The visual-model testing apparatus and testing method provided by the invention are simple in procedure, easy in fabrication, capable of realizing direct and in-depth observation, economic and good in operability, so the meso-scopic mechanism of seepage-stress-coupled internal piping is revealed preliminarily, and a testing foundation is provided for subsequent research.

A system and method for the geomechanical steering of the orientation of a wellbore is disclosed. In one embodiment, any available a priori data regarding the stress characteristics of a region of interest are used to develop a preliminary stress model for the region. A geosteered drilling operation is thereafter commenced, with the trajectory being steered in a direction relative to the stress model of the region. While drilling, real-time data is obtained from conventional down-hole instrumentation. The real-time data is used to refine the stress model for the region, such that the trajectory can be guided on an ongoing basis to achieve an optimal relationship with the measured stress characteristics of the region.

The invention relates to a stratum grouting simulation system, comprising a model load box (2) for containing rock soil, a loading subsystem (3) for loading the rock soil from the top end so as to restore an underground stress field environment, an underground water simulation subsystem (4) for controllably injecting water to the rock soil and discharging the water from the rock soil so as to simulate still water and dynamic water environments, a grouting subsystem (5) for grouting into the rock soil, a data acquisition subsystem (6) for measuring stress, strain and displacement data of the rock soil, and an alarm subsystem (7) for measuring deformation of the model load box (2), pressurizing pressure and grouting pressure and with an alarm function, wherein the side wall of the model load box (2) is provided with a detachable wall plate. The stratum grouting simulation system is lower in cost, and capable of simulating an excavation process, a deeper underground environment, dynamic water and vadose environments.

The invention relates to the field of oil-gas field exploration and development, particularly to a quantitative forecasting method of tectonic fissure occurrence. The quantitative forecasting method includes firstly determining a fissure mechanical property and rock mechanics parameters in a research area and restoring a paleotectonic map; secondly performing a numerical simulation of a paleostress field; thirdly selecting an appropriate rock failure principle according to the simulated paleostress field and the fissure mechanical property, and forecasting the best occurrence and the second-best occurrence of paleofissures on the basis of plane shearing strength distribution or profile shearing strength distribution of the stress field in the research area; coupling spatial positions of the paleorock stratum and the current rock stratum based on the simulated ant tracing technique, and then establishing a spatial switching theoretical model of the paleorock stratum and the current rock stratum; performing the quantitative analysis of fissure kinematics characteristics, and forecasting the occurrence of the current fissures according to that of the paleofissures.

The invention discloses a calculating method for the size of a fracturing and broken region of a horizontal well for shale. The calculating method comprises following steps of: A, utilizing the theory of crack propagation available to establish a hydraulic fracture extension model during a shale fracturing process; B, utilizing the theory of rock mechanics available to establish a model for stress field variation during a shale fracturing process; C, utilizing the theory of seepage mechanics available to establish a model for pressure field variation during a shale fracturing process; D, utilizing the rock breaking theory available to establish a rule model for natural fractures; E, combining the above four steps to calculate and represent the size of the fracturing and broken region by means of a calculation flow. The calculating method for the size of the fracturing and broken region of the horizontal well for shale has following beneficial effects: time and money spent on calculating the size of the broken region during fracture of the horizontal well for shale are saved so that the valuation of the size of the fracturing and broken region can be extensively prompted and applied.

The invention relates to a tunnel three-dimensional stress field simulator, which comprises a test box, lifting jacks and a hydraulic loading and control device, wherein the test box is arranged in a frame-shaped loading beam; a front loading plate is arranged in front of the test box; a rear loading plate is arranged on a rear wall of the test box; the peripheries of the front loading plate and the rear loading plate are connected through pull rods; the lifting jacks are respectively and fixedly arranged on an inner side of the loading beam and an inner surface of the front loading plate; two longitudinal support steel rails are arranged on a bottom part of the loading beam; and pulleys on bottom parts of the front loading plate and the rear loading plate are matched with the support steel rails. The device preferably simulates a three-dimensional surrounding rock stress field of a stratum where a shield tunnel and a mining method tunnel are located, and realizes construction simulation of excavation, support and the like of tunnel engineering under the condition of the three-dimensional stress field, so that the disturbance influence of construction on the surrounding rocks is researched, the stress performance of a tunnel structure under the condition of a complex stress field is analyzed, a more reliable test basis is provided for the design and the construction of the tunnel, and further the safety and the economy of the tunnel are ensured better.

A method for modeling flow properties over a series of time increments of a reservoir in an earth formation having a plurality of fractures is disclosed. The method includes: building a three-dimensional stress field representing stresses in the reservoir; building a three-dimensional discrete fracture network (NFM) having fracture flow properties using information obtained from a tool or changes to the stress field; running a flow simulation of the reservoir for a time increment using the NFM to model the flow properties of the reservoir for that time increment; computing a latest change in the three-dimensional stress field from the flow simulation; and incrementing the time increment and iterating the building the NFM using the latest change in the stress field, the running of the flow simulation using the latest NFM, and the computing a latest change in the stress field from the latest running of the flow simulation.

The present invention relates to a model test device, and specifically to a frozen soil mechanics model test device. The invention is characterized in that the frozen soil mechanics model test device has a full-steel box type structure which comprises a heat insulation box body, a baseboard temperature controller, a water supplying device, a loading device and a data collecting and processing device. The device adopts a welding mode for connecting to a whole, and only one side plate adopts bolt connection, wherein, the baseboard structure of heat insulation box body comprises a heat insulationbaseboard, a water supplying pool and a top plate of water supplying pool. The structure gives attention to the functions of water supplying and temperature control. The water supplying device comprises a water level controller, the water supplying pool and a water supplying pipeline device. The charging device comprises a hydraulic jack and a hydraulic oil pump. The data collecting and processing device comprises a DT500 / 600 series data collector, a XSL series temperature measuring instrument and various types of sensors. The device of the invention has the advantages of realizing unidirectional and bidirectional freezing condition, realizing the water supplying of water migration in freezing process, providing the load of model test load application damage, monitoring the temperature field and stress field of frozen soil, monitoring the frost heaving, subgrade settlement deformation, etc.; and realizing the automatic collection and analysis of test data in the test process.

The invention discloses a method for calculating a tight reservoir fracturing transformation volume area. The method comprises the following steps that multiple hydraulic fracture non-planar turning extension models, a formation stress field change model, a reservoir pressure file change model and a natural fracture failure criterion in the tight reservoir horizontal well fracturing process are established, geological parameters, horizontal well fracturing construction parameters and the total fracturing time are obtained, an initial fracture filter loss value, an initial fracture half-length value, an initial in-fracture pressure value, an initial fracture extension turning angle, initial permeability and an initial fracturing time value are endowed, all the models are calculated, and natural fracture failure point coordinate data is calculated; a spatial and numerical integration method is utilized to calculate tension failure transformation area volume and shear failure transformation area volume in a reservoir respectively, and the spaces of the two parts are united and regarded as a total transformation volume area. By adopting the method, accurate, economic and rapid tight reservoir horizontal well fracturing evaluation can be achieved, and the problem that effort, money and time are wasted in the existing tight reservoir horizontal well fracturing transformation volume area calculating process is solved.

The invention discloses a true triaxial multi-field multi-phase coupling dynamic test system and method. One end of an incident rod and one end of a transmission rod are fixed to the two ends of a triaxial loading device respectively; the triaxial loading device is a hexahedron, comprises three pressure device sets opposite to each other in pairs and is capable of separately controlling over compression and unloading of all faces of rock samples and changing the prestress loading value of six oil cylinders freely, both the incident rod and the transmission rod are provided with strain gages beneficial for measuring mechanical property of the rock samples when the rock samples are impacted; furthermore, a temperature effect test system and a chemical effect test system are additionally arranged, the temperature field and chemical field where the rock samples are located are changed by adjusting the temperature of the system and injecting different chemical solvents and various gas, meanwhile, the stress field borne by the rock samples is combined, the mechanical characteristics of the rock samples under the multi-field multi-phase coupling action of the stress field, the temperature field, the chemical field, solid, liquid, gas and the like, and data and theoretical supports are provided for follow-up studies.

The invention discloses a tight reservoir volume pressure crack network extension simulation and representation method. The method comprises the following steps of: firstly establishing a multi-crackstress interference-considered tight reservoir combined ground stress field calculation model by utilizing a displacement discontinuity method, mechanical mechanism analysis and crack initiation and extension criterions; aiming at a stress interference problem in volume pressure crack multi-crack extension process, establishing flow pressure drop distribution models, in primary and secondary cracks, of a fracturing fluid, so as to form a tight reservoir volume pressure crack horizontal well crack network extension theoretical model; and finally comprehensively analyzing influences, on volume pressure crack network structural morphology, of different factors, and defining a plurality of feature parameters to represent crack network structure morphology and attribute features. At last, the tight reservoir volume pressure crack network extension simulation and representation method is established. The tight reservoir volume pressure crack network extension simulation and representation method has the advantages of being comprehensive in model factor consideration, high in simulation effect and visual in result, and has a certain guiding significance for optimum design and efficient development of tight reservoir cracks.

A stressed field effect transistor and methods for its fabrication are provided. The field effect transistor comprises a silicon substrate with a gate insulator overlying the silicon substrate. A gate electrode overlies the gate insulator and defines a channel region in the silicon substrate underlying the gate electrode. A first silicon germanium region having a first thickness is embedded in the silicon substrate and contacts the channel region. A second silicon germanium region having a second thickness greater than the first thickness and spaced apart from the channel region is also embedded in the silicon substrate.