262 results about "Horizontal stress" patented technology

A method for estimating principal stresses of a subterranean formation from seismic data. In one embodiment, rock strength parameters from seismic data of the formation is first determined to calculate the anisotropic elastic properties of the formation. The three principal stresses of the formation: vertical stress, minimum horizontal stress, and maximum horizontal stress, is determined using at least the calculated anisotropic elastic properties and the rock strength parameters of the formation. From the estimated principal stresses, the differential ratio of the maximum and minimum horizontal stresses can be determined to indicate optimal zones for hydraulic fracturing. In another embodiment, a tectonic strain term is introduced to calibrate the estimated principal estimated stress to a known reference point. In yet another embodiment, hoop stress is incorporated to estimate the fracture initiation pressures.

The invention discloses a hydraulic fracturing technology for a horizontal well with fractures. The hydraulic fracturing technology comprises the following steps in sequence: (1), according to on-site information, calculating the stress difference values caused by major fractures and adjacent fractures; (2), according to the stress difference values caused by the major fractures and the adjacent fractures, calculating the pressure required when the fracture turns; (3), according to the pressure required when the fracture turns, determining the intensity of temporary plugging agents, and calculating the corresponding construction displacement; (4), according to the design parameters, conducting the segmental multi-cluster fracturing and impulse-type temporary plugging pressurizing technology on a reservoir stratum simultaneously. The hydraulic fracturing technology is mainly based on the horizontal stress difference drop-out values caused by the major fractures and the adjacent fractures, and simultaneously adopts the segmental multi-cluster fracturing and impulse-type temporary plugging pressurizing technology to force the fracture to turn, breaks through the technical bottleneck that the fractures are difficult to form in the stratum with a high stress difference and rudimentary natural fractures, and fills in the blank in the prior art.

The invention relates to quick preparation device and method of a saturated soil sample. Saturated clay is extruded by utilizing a load-vacuum combined consolidation principle so as to obtain a saturated clay sample with a low water content (the water content is lower than a plastic limit). The device comprises a sleeve, a base, a piston, a vacuum cavity and a fixing sleeve, wherein the sleeve is sequentially and respectively provided with a slide-fit piston, a cylindrical porous stone internally embedded with a horizontal pressure sensor and the fixing sleeve; the piston, the base and the sleeve are respectively provided with upper draining holes, lower draining holes and side draining holes; and a vacuum extraction hole is arranged on the vacuum cavity. The draining process of the saturated clay is accelerated under the extruding effect of the piston through the negative pressure (about 101.325kPa) condition of the vacuum cavity, and meanwhile, horizontal stress and vertical stress applied on the saturated clay are obtained through the horizontal pressure sensor and a vertical pressure sensor so as to further obtain a coefficient k0 of earth pressure at rest (a specific value of the horizontal pressure to the vertical pressure applied to the soil sample under the condition of no lateral deformation).

Maximum and minimum horizontal stresses, and horizontal to overburden stress ratio, are estimated using radial profiles of shear moduli. Inversion enables estimation of maximum and minimum horizontal stresses using radial profiles of three shear moduli associated with an orthogonal set of axes defined by the three principal stress directions. Differences in the far-field shear moduli are inverted together with two difference equations obtained from the radial profiles of the dipole shear moduli C44 and C55, and borehole stresses in the near-wellbore region. The horizontal to overburden stress ratio is estimated using differences in the compressional, dipole shear, and Stoneley shear slownesses at two depths in the same lithology interval where the formation exhibits azimuthal isotropy in cross-dipole dispersions, implying that horizontal stresses are nearly the same at all azimuths. The overburden to horizontal stress ratio in a formation with axial heterogeneity may also be estimated using the far-field Stoneley shear modulus C66 and dipole shear modulus C55 together with the radial variation of the dipole shear modulus C55 caused by near-wellbore stress concentrations.

An integrated style shear apparatus for rock structural plane comprises a frame system, a vertical loading system, a horizontal loading system, and a shearing system. Both the vertical loading system and the horizontal loading system are fixed on, and the shearing system is installed inside the frame system. The shearing system is used to prepare the sample of structural plane and actualize the shear test, the vertical loading system and the horizontal loading system are used to provide normal stress and shear stress for the shearing system respectively. The present invention also provides an experimental method by using the integrated style shear apparatus for rock structural plane, and steps of the method including: sample placement, sample adjustment, sample preparation, sample loading, instrument hookup, exerting normal stress, exerting horizontal stress, measurement and description of shear area, repeating experiment, and normal stress and shear stress calculation. The present invention can effectively reduce sample preparation error and experimental error, and can rapidly and accurately determine shear strength and deformation parameters of rock structural plane.

This invention applies to a bolt-on neck guitar or similar instrument or device. The mechanism of this invention, a multiple section hinge with one end flap attached to the neck and the other end flap attached to the body while the center section stays sandwiched between the neck and the body in normal use, allows the removal of the neck screws with the strings under tension by the hinge absorbing the horizontal stress produced by the tension of the strings. The neck is then rotated 180 degrees to rest on top of the body where it can be secured with a clamp or a strap for transportation or stowage. The neck holding screws can be replaced with a large single one, reducing the time required to loosen the neck, while still maintaining the possibility of using the normal four screws in addition to or in lieu of the single one if so desired, since the tone of the guitar is improved when the pressure of the neck-body junction is increased and distributed over a larger area. By folding the neck on top of the guitar, the bulk and the chances of damaging the instrument are greatly reduced, since the neck can be secured at both ends and the instrument can fit in boxes or pieces of luggage in which an ordinary guitar would not fit, in particular a carry-on size piece of luggage, which allows the traveler guitarist to have full control of the whereabouts of the instrument at all times.

The invention provides a method for increasing the fracture stimulated reservoir volume of shale gas. The method includes the following steps that firstly, the brittleness index of shale is fine analyzed and evaluated; secondly, a proper number of shower holes are selected; thirdly, induced fracturing testing is conducted on each segment; fourthly, acid pretreatment is conducted; fifthly, the amplitude of shale original horizontal stress difference relative to major fracture net pressure is judged, and a fracture is further treated; sixthly, balls are thrown according to the cluster number of perforated holes and the total number of the perforated holes. By fine analyzing and evaluating the brittleness index of shale, selecting reasonable perforated hole parameters, conducting induced fracturing testing on each segment of a horizontal well, well controlling the major fracture net pressure and well controlling a diverting agent in the fracture, generation of network fractures or volume fractures is improved in the shale gas well fracturing process, accordingly the fracture stimulated reservoir volume is increased, and finally the fracture flow conductivity is improved after shale gas fracturing.

Relating to the technical field of coal mine geology, the invention discloses a test device for simulating normal and reverse fault formation. The device comprises a test stand (1), an upper verticalloading apparatus (2), a left loading apparatus (3), a right loading apparatus (4), a hydraulic oil sac (5), a bearing steel plate (6), a steel block (7) and an angle adjustment apparatus (8). The test device provided by the invention is designed with the upper vertical loading apparatus, the left loading apparatus and the right loading apparatus controlled by a hydraulic servo system, realizes different horizontal force loading, and simulates horizontal stress at different depths, U-shaped push plates actually play a horizontal sealing role in simulation of similar stratum materials, and canindependently or wholly apply loads, especially can simulate the horizontal stress of regions with complex geological structure, realizes graded loading in the horizontal direction, is closer to the real effect, and realizes simulation of the formation process of normal fault and reverse fault in one equipment.

The invention provides a test device and a test method for a horizontal stress of compacted soil. The device comprises a limiting box, a sample barrel, a pressing device, and a load sensor. The limiting box is a rigid, rectangular box made of a steel plate with an open upper part. The sample barrel and a protective tube are hollow cuboid wherein the interior is rounded and the outside is square. The sample barrel and a half-pad are in contact with the bottom plate of the limiting box through a ball chute structure, and the two sides of the moving direction are respectively in contact with a sample barrel limit bolt and a load sensor. A half-pad and a half-spacer for reducing a hoop effect are arranged at both ends of the soil sample. The half-pad and the half-spacer are composed of two semicircular metal plates with the same radius. A soil sample layer preparation height is precisely controlled by the half-spacer and a limit block. The contact point of the load sensor is located at thecenter of the outer wall of a half-barrel. The total horizontal pressure of the compacted soil sample taken by the inner wall of the sample barrel is measured by the load sensor, and the horizontal stress is calculated. The error of the horizontal stress value of the compacted soil measured by the device is small, which can provide a more reliable and accurate stress basis for the design, construction and maintenance of embankment filling.

To predict residual settlement quantity and residual horizontal deformation quantity of ground where a liquefaction phenomenon has occurred due to earthquake. Soils in situ (stratum B to stratum D) are sampled from ground, and are made to be element test object stratums. A stratum whose characteristic is well-known, or the like may be substituted for a numerical model (stratum A). Next, setting of input conditions is performed, and vertical stress, horizontal stress and initial shear stress, which are equivalent to applied load that the ground at a depth of the point suffers, are worked on to each stratum. This recreates a stress status of soil before earthquake occurs. Then, shear displacement and the movement quantity of interstitial water by earthquake are given to the test piece, and the quantity of shear stress and pore water pressure, which have occurred, is obtained. In the element test execution stratum, displacement computed for stratum element and the movement quantity of interstitial water are actually given to each element to measure restoring force and the pore water pressure. By sequentially repeating the steps, it is possible to simulate the behavior of the liquefaction phenomenon.

A method for measuring horizontal stress of fine granulated saturation soil at original place in real time calculates out degree U of consolidation and horizontal consolidation coefficient C as well as static side pressure coefficient K by obtaining relation curve of horizontal pressure R at saturation soil layer deep position to time T and by applying three ¿C points calculation means to calculate horizontal stress R1 at initial time and horizontal stress at time of finalizing excess pore water pressure evanish . The probe for realizing said method is also disclosed.

A method of increasing productivity and recovery of wells in oil and gas fields includes determining a direction of maximal horizontal stresses, producing at least two wells so that they are spaced from one another in a direction corresponding to the direction of the maximum horizontal stresses, forming in at least one of the wells at least one vertical slot oriented substantially from the at least one well to the other of the wells, and introducing a hydrofracturing fluid at least into the at least one well to produce a hydraulic fracture in direction from the at least one well to the other well.

The present disclosure is related to methods and apparatuses for acoustic velocity well logging. The method may include estimating a magnitude of a principal horizontal stress in a borehole in a formation. The method may include obtaining a far field stress orientation and making a measurement of near borehole stress orientation. The present disclosure also includes an apparatus configured to be conveyed into a borehole and perform the method. Formation stresses and directions may be estimated.

The invention discloses a test device for a shearing property of a multipurpose interface and a test method thereof. The test device comprises an environmental cabinet and a test piece arranged in theenvironmental cabinet; the test device is characterized in that fixing devices are arranged on the periphery of the test piece; a horizontal loading device and a horizontal displacement sensor are arranged on a horizontal plane of the test piece; a vertical loading device is arranged on a vertical plane of the test piece; a horizontal force presser and a horizontal stress sensor are arranged between the horizontal loading device and the test piece; a vertical force presser and a vertical stress sensor are arranged between the vertical loading device and the test piece; a controller is arranged on the exterior of the environmental cabinet; the controller is electrically connected with the horizontal stress sensor, the vertical stress sensor and the horizontal displacement sensor. The testdevice is capable of realizing real-time recording and monitoring of extreme damage and fatigue destructive property data of the shearing interface so as to finish test. The test device disclosed by the invention can be used for testing the mechanical properties of the shearing interface. The test data can be used for effectively evaluating shear strength and shearing fatigue property of various compound structures, such as paving interlayer interfaces and different dielectric material shearing interfaces.

This invention discloses a rock core clamper, which can distinguish the horizontal stress and vertical stress in the stratum rock and mock the stratum stress status in reality and can be used to measure the porosity and penetration degree of the rock and their varying rule with the stress. The rock core clamper mocks couple functions with multiple stress fields, which comprises flow penetrate board, pressure guiding block, upper cover, base socket and hollow rubber ring. And it has two set pressure systems and the pressure exerted on the rock core through the pressure-guiding block makes the rock core generate vertical stress and the hollow rubber ring is filled with flow to press the rock core and makes the rock core generate horizontal stress.

The invention relates to a transformer substation flexible circuit conductor blanking length numerical solution method based on catenary. A transformer substation flexible circuit conductor is divided into a strain insulator string and a flexible bus, structural parameters and material parameters are determined, the hitch point of the strain insulator string serves as an origin, a X-Y coordinate system is established, and an analysis model of transformer substation flexible circuit conductor blanking length is established; secondly, a sag step length dichotomy adjustment module is constructed; thirdly, a horizontal stress calculation adjustment module is established; fourthly, a hardware space coordinate calculation module is established; fifthly, a total sag calculation error adjustment module is established; finally, the calculation of modules is combined, and the blanking length of the flexible circuit conductor can be obtained. On the basis of the known structural parameters and material parameters, stress is obtained by using sag, designed sag serves as a limiting condition, by means of a numerical method, accurate sag, horizontal stress and the like are obtained, the accurate flexible circuit conductor blanking length is obtained, and the transformer substation flexible circuit conductor blanking length numerical solution method has very high application value.

The invention discloses a method and a system for calculating the icing thickness of a tension resistant tower wire based on a weighing method. The method comprises the following steps: firstly, obtaining the vertical force and the horizontal tension of the tension resistant tower wire without icing; then, calculating and obtaining the horizontal stress of the wire without icing according to the horizontal tension without icing; obtaining the air temperature and the second monitoring tension value of a suspension point during icing; calculating the vertical force and the horizontal tension during icing; calculating the angle of inclination during icing, and further obtaining the weight per unit length of the iced wire; and finally, obtaining the icing thickness of the wire according to the weight per unit length of the iced wire, and the dead weight per unit length of the wire without icing. Therefore, the defect that a model for calculating the icing thickness of the tension resistant tower wire is lacked in the engineering application is remedied. Besides, the method has the advantages of few input monitoring parameters, low requirements for monitoring equipment, high calculating accuracy and the like. The effect of the method in the practical engineering application is good, and the method has good popularization and application prospects.

A stress-optimized structural support which may be utilized as a beam or assembled with similar supports to form a building floor or roof panel or a bridge deck utilizes an open core element, made preferably of suitably treated fluted paper, upper and lower thin skin sheets, preferably steel skins, and a layer of concrete poured over the top skin. Modules comprising the hollow core element and the upper and lower skin sheets are fabricated to lengths required for building floor, roof or bridge spans and, when joined by welding or otherwise joining the upper and lower skin sheets of adjacent elements along their full lengths, provide a floor or roof deck structure of a large span with horizontal stresses distributed omnidirectionally. A post-stressing tensile system redistributes and reduces the load on the roof deck by about one-half. Small building decks utilizing the stress redistribution system can be combined to build a large span roof in which multiple tensioning systems are coordinated to simultaneously effect the load redistribution.

The invention discloses a caisson composite foundation provided with suction type apron shells and semi-rigid connection piles. The caisson composite foundation comprises a caisson, the suction type apron shells, a semi-rigid cushion layer and the preformed piles. The tops of the multiple suction type apron shells are fixedly connected to the circumference of the bottom of the caisson; the semi-rigid cushion layer is formed below the caisson and makes direct contact with the bottom of the caisson to be a whole; the top ends of the multiple preformed piles are fixedly connected to the interior of the semi-rigid cushion layer and are connected with the semi-rigid cushion layer to be a whole; the bottom ends of the multiple preformed piles extend the deep position of the foundation. According to the caisson composite foundation provided with the suction type apron shells and the semi-rigid connection piles, vertical stress is mainly borne by the pile groups, horizontal stress is mainly borne by the suction type apron shells, and therefore the horizontal stress, vertical stress, bending resistance stress and anti-torsion stress properties of the composite foundation are good, the erosion prevention performance is high, and the economical efficiency is good.

A method for predicting the in-situ stress of shale gas formations based on 3D seismic data belongs to the field of shale gas geophysical exploration. The method first uses 3D pre-stack seismic data and logging data to perform pre-stack elastic parameter inversion to obtain shale The elastic parameters of the gas formation; then the formation pressure is calculated by using the seismic layer velocity obtained based on the 3D post-stack seismic data and the stacked velocity data; then the curvature and horizontal direction of the shale gas formation are calculated based on the 3D post-stack seismic data and seismic horizon data Structural strain; finally, according to the linear isotropic combined spring model, the maximum horizontal principal stress, the minimum horizontal principal stress and the horizontal stress difference of the shale gas formation are calculated using three-dimensional data such as elastic parameters, formation pressure, and structural strain. The beneficial effect of the invention is that the three-dimensional geostress data body of the shale gas formation with high precision can be obtained effectively.

This invention relates to a method for determining direction and relative magnitude of maximum horizontal stress in sedimentary basins within Earth's crust. In particular the method uses seismic reflection data in determining the direction and magnitude of stresses. The method involves identifying from seismic data faults which cut the upper continental crust and uses those faults in conjunction with globally simultaneous compressional structures such as anticline to map the horizontal stresses. The invention has a particular application in the hydrocarbon exploration and production industry and has the advantage of providing the results pre-drill.

The invention belongs to a hard roof control range, and particularly discloses a crack initiation method adopting crack prefabricating and orientated hydraulic fracturing. The crack initiation methodadopting crack prefabricating and orientated hydraulic fracturing comprises the steps that firstly the magnitude and direction of the maximum horizontal stress of a hard rock stratum are measured, andthen vertically upward or obliquely upward drilling holes are constructed from one side of an open-off cut coal pillar of a working face or a conveying gate road or one side of a return wind gate road channel or the above three positions to the hard rock stratum, after the drilling construction is completed, cracks are symmetrically prefabricated on both sides of hard rock stratum sections in thedrilling holes in the axial direction, after the prefabrication of the cracks is completed, the drilling holes are rinsed with clean water, then waterproofing agents are applied in the drilling holes, and after the waterproofing agents solidify, the drilling holes are sealed and fractured. The crack initiation method adopting crack prefabricating and orientated hydraulic fracturing overcomes thedisadvantages that when rock permeability is good and the prefabricated cracks and the maximum horizontal stress have a certain included angle, the prefabricated cracks cannot provide the crack initiation position due to the fluid loss of fracturing fluid by rock, so that the crack initiation position and the direction of hydraulic crack propagation are effectively controlled, the spacing of the fractured drilling holes is increased, and the cost of the drilling holes and labor intensity are reduced.

The invention discloses a method for testing the tensile mechanical performance of TiAl-base alloy, comprising the steps of preparing raw materials, designing the size of a sample under test, processing and cutting the sample under test, processing the surface of the sample under test, loading and unloading the sample under test repeatedly and measuring the sample under test repeatedly. The sample which has no gap and is under the in-situ tension test by a scanning electron microscope (SEM) is designed and is ruptured under uniform stress to increase the plastic deformation region. The sample is tensed by being repeatedly loaded and unloaded with horizontal stress points on a standard mechanical performance curve. The method is particularly suitable for testing the tensile mechanical performance of the brittle material such as the TiAl-base alloy and can ensure that the morphology of the non-uniform plastic deformation of the brittle material such as the TiAl-base alloy which is tensed repeatedly can be observed in detail, the generation of the crack and the plastic deformation region of the brittle material such as the TiAl-base alloy can be observed, and the mechanical performance of the brittle material such as the TiAl-base alloy can be researched well.

The invention relates to a partition support system for a large-area deep foundation pit under forward and backward working condition, and a construction method thereof. In the support system, a TRD waterproof curtain forms a closed water barrier wall on the outer side of a deep foundation pit. The inner side of the TRD waterproof curtain is provided with a row of fender posts. The middle part of the deep foundation pit is provided with a tri-axial stirring pile, so as to divide the deep foundation pit into two regions, and a row of fender posts are arranged on a side of the tri-axial stirring pile. The deep foundation pit is internally provided with a plurality of upright piles. Each upright pile is connected with a latticed column. The fender posts are internally provided with a plurality of reinforced concrete internal supports. Through corresponding latticed column, the internal supports bear the internal support which forms the deep foundation pit. The construction method comprises: performing earth excavation and support construction on a region, and performing structural construction from a foundation mat upward, before a first support is dismounted, performing support changing construction of a structural steel diagonal supporting beam, ensuring horizontal stress of the other region to be transmitted to a structural beam plate of the region which is constructed firstly; and performing earth excavation and support construction on the other region from top to bottom.

Methods and systems for analyzing subterranean formations in-situ stress are disclosed. A method for extracting geological horizon on-demand from a 3D seismic data set, comprises receiving sonic log data; computing the anisotropic shear moduli C44, C55 and C66; determining in-situ stress type and selecting an in-situ stress expression corresponding to the in-situ stress type; computing stress regime factor Q of the formation interval; and computing and outputting the maximum stress σH by using the stress regime factor Q, Vertical stress σv and Minimum horizontal stress σh.

The invention relates to a calculation method for a blanking length mathematical model of a flexible lead of a 500kV substation. The method comprises the steps of firstly determining an input parameter and resolving a horizontal stress Rho0 by a sag inverse formula; judging whether the resultant force T0 of suspension points at two sides of the flexible lead is smaller than the damage load gravity [T0] of a U-shaped hanging ring; calculating the space position and stress condition of each part by a catenary method from insulator strings at left and right sides in sequence; then judging whether the resultant force T1 at the connection position between the flexible lead and a tension resistant string clamp is smaller than the maximum bearing pull force [T1] of the lead; then dividing the lead into a plurality of equal parts and resolving the space position and stress of each section of lead by using the catenary method; finally judging the horizontal stress of the lowest point and calculating the actual sag and blanking length of the lead. The spatial form of each part of the flexible lead can be accurately presented, the sag size of the flexible lead is controlled, the accurate blanking length of the flexible lead is calculated, the consistency of the spatial form of the three-phase lead is ensured and the calculation method has very high credibility.

The present invention is measurement method of plastic tensile strength of cement-base material. Two figure-8 shaped semi-molds halved along neck cross section, bottom plate, support plate, etc. are adopted, so that horizontally set plastic material in gravitational field may be supported and measured via applying horizontal stress for measuring plastic tensile strength. The method may be used in measuring the plastic tensile strength of cement-base material, such as slurry, mortar, concrete and their composite material, in any time from formation to final solidification. The present invention may be used in the research, development, production, application and management of cement-base material for evaluating cracking performance, etc.

A method for realizing horizontal stress sense based on double mode photon crystal optical fiber includes coupling output light of laser into zero double refraction or high double refraction and double mode photon crystal optical fiber by horizontal dislocation mode after said output light passes through polarization controller, setting double mode photon crystal optical fiber in force receiving unit for sensing horizontal stress exerted from outside, utilizing far field light spot to detect space light field formed by double mode interference for obtaining detection result of horizontal stress. The system for realizing said method is also disclosed.

The invention discloses a method and a device of optimizing staged fracturing parameters of a horizontal well. The method comprises the steps that rock elasticity parameters and mineral composition parameters of sample point strata in a horizontal well exploration work area are acquired; a rock elasticity parameter data body and a mineral composition parameter data body of the work area are acquired; based on the rock elasticity parameters and the mineral composition parameters, as well as the rock elasticity parameter data body and the mineral composition parameter data body, brittleness parameters and total organic carbon content parameters of the strata in the work area are acquired; fracture layout features and differential horizontal stress ratios of the work area are acquired; and based on the brittleness parameters and the total organic carbon content parameters, as well as the fracture layout features and the differential horizontal stress ratios, the staged fracturing parameters of the work area are optimized. According to the method and the device, the optimization effect of the staged fracturing parameters of the horizontal well can be improved, and a guarantee of the realization of maximized oil and gas resource capacity is provided.