131 results about "Effective stress" patented technology

The invention relates to a concrete temperature-stress two-parameter cooperative monitoring and early warning method and system, and belongs to the technical field of concrete structure health monitoring, and the method comprises the steps: activating a composite sensor network disposed at a preset position of a concrete structure, and executing a sensor self-calibration mode; the method comprises the following steps: synchronously acquiring temperature and stress original monitoring data of each node, processing based on an altitude air pressure compensation algorithm, and outputting a temperature gradient field matrix and a stress tensor sequence with aligned time domains; the method comprises the following steps: separately calculating a thermal stress component and an effective stress component, performing integral calculation on hydration reactivity, generating a multi-dimensional feature vector set, inputting a pre-constructed prediction model, executing time sequence evolution prediction, calculating a crack probability value, performing environment correction in combination with real-time environment parameters, outputting a risk level identifier, and matching a preset regulation and control strategy. And generating an equipment control instruction set and executing corresponding regulation and control actions. According to the invention, the accuracy and timeliness of crack risk prediction can be improved.

Systems, methods, and apparatus for characterizing reservoirs are discussed. As an example, a method for characterizing a reservoir is discussed that includes determining a ki parameter, a αE parameter, and a αP parameter based at least in part on the at least four pairs of effective stress and permeability; and predicting a hydrocarbon production rate from reservoir represented by the sample rock based at least in part on the ki parameter, the αE parameter, and the αP parameter.

The invention discloses a double-row medium-length hole blasting method for a filling stope. According to the method, a theoretical value range of each blasting parameter is deduced according to field engineering practice, an ore rock blasting crushing mechanism and a blasting parameter theoretical formula. The method comprises the following steps of: constructing a stope blasting model with different hole bottom distances, explosive unit consumption and resistance line combinations by using ANSYS numerical simulation software in combination with physical and mechanical properties of ore rocks and field explosive performance parameters, and preferably selecting double-row medium-length hole blasting parameters according to a chamber effective stress distribution rule and a roof area vibration velocity peak value of the ANSYS blasting model. According to the method, by selecting the double-row optimal medium-length hole blasting parameters, it is guaranteed that ore rocks in the chamber are fully crushed, the effective stress invading the roof and the blasting vibration velocity peak value are reduced, and the roof is prevented from being damaged. And meanwhile, the explosive loading amount is reduced, the economic cost is reduced, and the production efficiency of a mine is improved.

The invention provides a concrete elastic-plastic damage constitutive model construction method and system, belongs to the field of computers, and solves the problems that in the prior art, an integral or gradient enhanced regularization method is adopted to establish a non-local constitutive model, but the two methods require relatively fine finite element grid division, and numerical value implementation is very difficult. Comprising the following steps: 1, determining a damage variable, nominal stress, effective stress and an elastic-plastic damage stress-strain relationship, and decomposing the effective stress according to tension and compression characteristics; 2, in the effective stress space, a concrete elastic-plastic damage constitutive model is established; and step 3, based on an energy regularization method, determining a tensile damage variable, a compression damage variable and a corresponding stress-strain relationship, and in combination with a plastic loading and unloading rule, constructing a concrete elastic-plastic damage constitutive model based on energy regularization. The invention provides the construction method of the PC box girder concrete elastic-plastic damage constitutive model under the non-uniform constraint, and the application range is wide.

The invention discloses a geotechnical engineering catastrophe dynamic real-time intelligent early warning method and system based on displacement monitoring, and the method comprises the steps: collecting the real-time displacement data and related parameters of a geotechnical engineering region through displacement monitoring equipment, and transmitting the real-time displacement data and related parameters to a bank slope stability evolution analysis platform to establish a multi-dimensional database; calling a fractured rock mass effective stress analysis model to calculate rock mass effective stress distribution characteristics, and inputting a multi-grid sliding surface stress calculation algorithm to obtain a potential sliding surface stress state and a critical threshold value; inputting the sliding surface stress parameters and the displacement data into a multi-field coupling analysis learning prediction model to obtain a displacement evolution trend and a catastrophe risk coefficient; and finally, real-time early warning information is generated and fed back through the catastrophe dynamic real-time intelligent early warning module. The method improves the real-time performance and accuracy of early warning, can effectively guarantee the safety of geotechnical engineering, and is suitable for catastrophe early warning scenes of geotechnical engineering such as bank slopes and foundation pits.

The invention discloses an invasion limit surrounding rock excavation method for a large deformation section of soft rock, and relates to the technical field of invasion limit surrounding rock excavation construction for the large deformation section of the soft rock. The invasion limit surrounding rock excavation method for the large deformation section of the soft rock comprises the steps that refined partitioning of an invasion limit body is achieved through dense scanning and loose circle testing; dividing the invasion limiting body into a core pressure-bearing area and a peripheral stress relaxation area; a main stress diversion arch crossing an invasion limit section is constructed through full-ring radial grouting reinforcement and erection of a strong profile steel temporary cover arch, and effective stress transfer is achieved; the mode of subarea gradual type dismantling and chiseling and instant supporting is adopted, a peripheral stress relaxation area is treated firstly, then a core pressure-bearing area is treated, and surrounding rock disturbance is reduced; the circumferential stress equalization is realized by compensating grouting in stages and dynamically adjusting the grouting pressure according to real-time monitoring data. According to the method, the excavation construction safety of the invasion limit surrounding rock of the large deformation section of the soft rock can be improved, surrounding rock disturbance is reduced, stress distribution is optimized, and the treatment efficiency of the invasion limit surrounding rock is improved.

The invention relates to the technical field of data processing, discloses a coupling calculation method for seepage deformation analysis of a dam body-dam foundation of a high earth and rockfill dam, and aims at solving the problem that a data acquisition method of an existing terminal device is poor in accuracy and safety. Carrying out grid division on a solid domain and a reservoir water external flow field area; performing transient calculation on the reservoir water external flow field area based on a computational fluid mechanics method, and solving an RANS equation to obtain flow field evolution data of the reservoir water external flow field area; the pressure field is applied to the surfaces of the dam body and the dam foundation, seepage-deformation coupling calculation is conducted on a solid domain based on a Biot equation in a u-p form, and displacement fields, pore pressure fields and effective stress fields of the dam body and the dam foundation are obtained; and post-processing the calculation result, and extracting response features. The accuracy of high earth and rockfill dam body-dam foundation seepage deformation analysis coupling calculation is improved, and the method is particularly suitable for high earth and rockfill dams with dam foundation defects.

The invention provides a visual characterization method, device and equipment for a deformation rule of a rock microstructure, and relates to the technical field of oil-gas exploration. The method comprises the following steps: acquiring scanning grey-scale map data of an internal structure of a rock under different load conditions; establishing a rock three-dimensional digital core model under different load conditions according to the scanned grey-scale map data and the pre-trained neural network; performing pore structure feature extraction processing according to the rock three-dimensional digital core model to obtain rock pore structure feature parameters, and representing a dynamic deformation rule of the rock micro-pore structure along with effective stress loading according to the rock pore structure feature parameters; performing fracture morphological feature extraction processing according to the rock three-dimensional digital core model to obtain a rock fracture morphological feature parameter system, and representing a rock internal fracture morphological deformation evolution rule according to the rock fracture morphological feature parameter system. According to the method provided by the invention, the real rock micro-pore structure is accurately reflected.

The invention relates to a shale reservoir stratum pore pressure logging prediction method based on an improved Bowers equation, and the method comprises the steps: building an acoustic wave velocity response equation considering the influence of density and organic matter content in combination with the Bowers equation; carrying out a soaking experiment on the rock sample, and obtaining formation acoustic velocity and density subjected to hydration correction based on interval transit time, density and depth resistivity in logging information: obtaining a Bowers equation of a research formation based on the acoustic velocity and density of an undisturbed formation subjected to hydration correction; the Bowers equation of the research stratum is corrected, and an improved Bowers equation of the research stratum is obtained; based on an improved Bowers equation, effective stress and vertical stress of the stratum are calculated; and based on the effective stress and the vertical stress of the stratum, calculating to obtain the stratum pore pressure of the research stratum. According to the corrected Bowers formation pore pressure prediction model established by the invention, the prediction precision is obviously improved, and the development cost is reduced while the occurrence of construction accidents is reduced.

The invention discloses a method for determining the minimum cylindrical shell thickness of a core-filled concrete column, and relates to the technical field of constructions.The method for determining the minimum cylindrical shell thickness comprises the steps that the first cylindrical shell thickness meeting the design bearing capacity condition of the core-filled concrete column is calculated; calculating the thickness of a second cylindrical shell meeting the requirements of the construction pouring stage; calculating a third cylindrical shell thickness meeting the construction requirement that the stirrups and the longitudinal bars are pre-embedded in the cylindrical shell; and selecting the maximum value of the first cylindrical shell thickness, the second cylindrical shell thickness and the third cylindrical shell thickness, and determining the maximum value as the minimum cylindrical shell thickness. According to the method, the minimum column shell thickness value of the core-filled concrete column under different column heights and different design bearing capacities can be quantitatively determined in the design process through an effective acting stress model, a thick-wall cylinder theory and other theoretical models, the core-filled concrete column designed according to the minimum column shell thickness meets the requirements of engineering design, column shell materials can be saved, and the cost is reduced. And the utilization rate of the column shell UHPC material in the core-filled concrete column is improved.

The invention relates to the technical field of geotechnical engineering, in particular to a sandy soil liquefaction discrimination method which comprises the following steps: collecting geological survey data, seismic parameters and soil test and in-situ test results of a target area, and determining parameters required by numerical simulation; a three-dimensional calculation model is constructed, grids are subdivided, a constitutive model is set, static balance and an initial pore pressure field are established, and the accuracy of the model is verified through mechanical balance and fluid balance; dynamic waves are processed and applied, a free field boundary, a seepage mode and mechanical damping are set, a coupling constitutive model is constructed, and monitoring points are arranged on the liquefiable stratum; determining liquefaction according to the effective stress, the pore water pressure time history curve and the excess pore pressure ratio; according to the invention, vertical and lateral deformation after liquefaction can be predicted, quantitative deformation data can be provided, errors of a standard penetration test are reduced, and the problems of small application range and strong regionality are solved; and the judgment result is more accurate through the verification of the excess pore pressure ratio, and a reliable basis is provided for the design of engineering anti-liquefaction measures.

The application provides a calculation method of pore pressure of a tectonic compression formation. The calculation method of pore pressure of the tectonic compression formation comprises the following steps: S1, obtaining a density trend curve, and performing integral calculation on the density trend curve to obtain overburden pressure S V ; S2, determining total porosity POR of the formation based on acoustic logging, density logging, neutron logging or nuclear magnetic resonance logging; S3, analyzing characteristics of a target layer section to determine a tectonic compression coefficient ACm_C of the formation; S4, solving a pore pressure coefficient PP of a mudstone section based on a pore pressure model corrected based on the tectonic compression coefficient ACm_C; S5, determining a relationship between effective stress P eff and biot coefficient α and total porosity POR; and S6, inversely deducing a pore pressure coefficient of a reservoir section according to the relationship between the effective stress P eff and the total porosity POR. The application solves the problem of low calculation accuracy of the pore pressure calculation method in the prior art.

The invention discloses a shield tunnel electromechanical numerical control and testing integrated model test platform and method, and relates to the technical field of shield construction testing. Comprising the following steps: S1, collecting water-soil machine three-dimensional coupling test data in real time, and performing data preprocessing; s2, reconstructing a pore pressure, water content, stress and average effective stress multi-distribution field; multiple types of residual parameters are calculated, the three-dimensional water-soil coupling balance is evaluated, the hydraulic stress state is judged, and balance control over flow and pressure is executed; s3, when the hydraulic stress state is imbalanced, evaluating and correcting the flux adjusting quantity, and realizing water inlet and outlet flow adjustment; and S4, based on the three-dimensional water-soil coupling balance change rate and the correction flux regulation variable change rate, evaluating dynamic response consistency, updating parameters and correcting a threshold value. The problem that the test precision and the subsequent construction safety are affected due to the fact that an existing shield test device cannot accurately reflect the stress seepage collaborative change rule in the shield construction process under the complex water-rich stratum is solved.

The invention relates to the technical field of geotechnical engineering and geological engineering, and discloses a CO2 geological utilization and storage induced earthquake multi-field coupling numerical analysis method, which comprises the following steps of 1, acquiring rock fault geometric characteristic parameters, reservoir geological characteristic parameters, tectonic stress characteristic parameters and construction parameters of a well production point; 2, simulating the CO2 phase change process according to the seepage field, the temperature field, the chemical field and the stress field, constructing a heat-fluid-solid-chemical multi-field coupling mathematical model in the CO2 injection process, including a seepage source confluence item, a thermal field equation, a reaction rate and effective stress, and realizing simulation of the whole fault activation-fracture process under the heat-fluid-solid-chemical multi-field coupling action; the multi-field coupling analysis is more comprehensive; 3, injection-induced fault activation simulation is carried out, and normal stress and shear stress of the fault surface and the fault slip rate are analyzed; and step 4, non-seismic slippage and seismic slippage are evaluated, corresponding seismic moments and induced seismic magnitudes are output, and the seismic nucleation precision is high.

According to the method for testing the effective prestress of the existing concrete structure considering the reverse friction influence, a plurality of prestressed tendons are pre-buried in concrete to form an in-service prestressed concrete member, and one prestressed tendon at the end part of the concrete is stretched by using a supplementary tensioning tool; in the stretching process, the obtained stretching stress of the prestressed tendon, the corresponding stretching length measured from the failure of friction constraint between an anchorage device and a wedge-shaped clamping piece of the prestressed tendon and the effective stress of the in-service prestressed concrete member are recorded for at least five times, and the obtained stretching stress and the corresponding stretching length are the secondary reverse friction force influence stress; selecting the friction coefficient of local deviation of the length per meter in the pore channel and the friction coefficient between the prestressed tendon and the wall of the pore channel from the anti-friction influence length corresponding to the anti-friction influence stress; finding out an optimal one; and calculating the effective stress of the out-service prestressed concrete member by using any recorded tensile length.

This invention provides a method and system for calculating pile foundation length, relating to the field of pile foundation design technology. Specific steps include: calculating environmental characteristic parameters based on the maximum flow velocity and highest water level under a preset return period using the moment estimation method to accurately quantify extreme hydrological evolution trends; constructing a formula for calculating the maximum scour depth by combining water-blocking characteristic parameters to obtain the scour reference surface, thereby overcoming the defects of physical boundary failure; reconstructing the effective stress field of the underlying soil layer based on the scour reference surface and stress release logic to realistically restore the physical unloading effect; calculating the side friction resistance at each depth using nonlinear strength decay logic to accurately assess the degradation loss of pile-soil bearing capacity; and outputting the optimal pile foundation length using a dynamic step-size iterative algorithm under a preset load safety threshold, based on the preset ultimate end resistance of the pile end bearing layer, ensuring the bottom line of flood control mechanical safety while avoiding over-design of the structure.

The present invention discloses a rock and soil static side pressure simulation device and an effective stress calculation method, wherein the rock and soil static side pressure simulation device includes a metering cylinder, a liquid inlet box, a test cylinder, a liquid outlet box and a metering cylinder; a support structure is provided on the top of the liquid inlet box, the support structure includes a hydraulic oil cylinder and an axial force gauge, the axial force gauge is provided on the top of the liquid inlet box, and the hydraulic rod of the hydraulic oil cylinder is pressed against the axial force gauge; a plurality of pressure sensors are provided on the side of the test cylinder. The present invention provides a rock and soil static side pressure simulation device and an effective stress calculation method, which can directly measure the rock and soil static side pressure of reshaped soil or original soil taken on site, directly simulate the actual situation of the rock and soil on the foundation pit side, and make the foundation pit static side pressure test results more accurate. At the same time, it breaks through the traditional concept of Terzaghi's effective stress and proposes a new effective stress calculation formula to provide support for the development of theoretical soil mechanics.

The invention relates to the technical field of oil exploration, in particular to a quantitative prediction method for dynamic permeability of fractures of fractured oil and gas reservoirs. According to the method, an underground crack-free rock core sample is adopted for artificial crack forming, and a relation chart of the confining pressure and the actually-measured crack permeability is obtained; the method comprises the following steps: predicting effective stress change in a development process by utilizing actual measurement formation pressure data of a single well, carrying out numerical simulation of effective stress in the development process on the basis of finite element modeling, and determining a relationship between effective stress of a target well and production time; and establishing a relationship between the effective stress of the target well and the fracture permeability in combination with a calculation result of the fracture permeability of the single well imaging logging, and further establishing a relationship between the production time and the fracture dynamic permeability, thereby realizing quantitative prediction of the change of the fracture dynamic permeability in the development process.

The invention relates to a saturated sand dynamic constitutive model construction method considering pore pressure fluctuation growth, which comprises the following steps: determining total pore water pressure including residual pore pressure component and transient pore pressure component, and constructing a normalized stress ratio skeleton curve independent of a pore pressure state; correcting the total pore water pressure to obtain corrected pore water pressure, and updating the average effective stress at the current moment by using the corrected pore water pressure; coupling the normalized stress ratio skeleton curve and the updated average effective stress to obtain a maximum shear stress value; the maximum shear stress value is used as a target state point, a dynamic virtual hysteretic curve is constructed, the stress-strain behavior of saturated sandy soil is described, accumulated damage and alternate shear shrinkage-shear expansion effects of a soil body in the cyclic loading process can be effectively considered, a pore pressure development curve and cyclic shear stress-strain response which better conform to the test rule are captured, and the test accuracy is improved. And a valuable tool is provided for evaluating the response and liquefaction strength of the saturated sand under the undrained cyclic loading condition.

The application discloses a kind of non-saturated solidified soil fatigue cracking damage prediction methods based on energy-mechanics method.The application introduces the effective stress formula proposed by Lytton and gives the solution method of relevant parameters in combination with energy-mechanics method, obtains the damage density evolution trend of non-saturated solidified soil material, finally based on the theory of fracture mechanics and continuous damage mechanics, on the basis of Paris equation, introduce damage density function, and based on dissipation strain energy DSE, the expression form of J integral is obtained, so as to establish the damage evolution prediction model capable of characterizing the multi-crack cracking process.The application solves the problem that the previous solidified soil fatigue cracking model cannot effectively reflect the influence of unsaturated characteristics on soil material cracking, and the model is based on the basis of mechanics theory, can better predict the multi-crack fatigue cracking damage evolution process from the mechanism level of non-saturated solidified soil material fatigue cracking, and provides basis and guidance for the design of solidified soil material and solidified soil road structure.

The invention relates to the technical field of petroleum geophysical exploration, in particular to a crustal stress calculation method, system and device and a computer program product, and the method comprises the steps: calculating an elastic parameter body and stratum thickness of a target stratum; calculating reservoir pore pressure and effective stress according to the elastic parameter body; calculating a horizontal maximum principal strain and a horizontal minimum principal strain according to the stratum thickness; and according to the horizontal maximum main strain and the horizontal minimum main strain, calculating the seismic crustal stress of the stratum based on a combined spring model considering the porosity. According to the reservoir pore pressure quantitative prediction method considering the influence of the shear wave velocity and the porosity, a Ricker wavelet function differential operator is innovatively constructed, accurate curvature values in different directions can be obtained, an accurate horizontal strain value can be obtained accordingly, ground stress is solved by adopting an improved combined spring model, and the prediction accuracy of the reservoir pore pressure is improved. And the accuracy of ground stress prediction by using the seismic data is greatly improved.

The application discloses a silt state parameter inversion method based on a CPTU calibration tank test, and belongs to the technical field of indoor test of geotechnical engineering; firstly, the CPTU calibration tank is used to carry out silt CPTU penetration tests under different overburden stresses, and an initial silt state parameter model is constructed; then, the influence of pore water pressure of the soil body on the silt state parameter is considered, a relationship between the overburden effective stress and the silt state parameter is established, and a corrected silt state parameter model is obtained; finally, the initial silt state parameter model and the corrected silt state parameter model are combined to obtain a total soil body state parameter model considering the influence of the pore water pressure of the soil body. The scheme can realize accurate acquisition of the silt state parameter of a sea area, has the advantages of rapidness, simplicity, high reliability of test results and the like, provides a theoretical support for safe construction of related facilities such as a submarine tunnel, a cable laying or an oil pipeline, and has important significance for evaluation of silt seabed liquefaction instability.

The application discloses a method for calculating the inner friction coefficient of a three-dimensional natural fracture wall surface in space, which comprises the following steps: determining the strike of the natural fracture and the included angle between the natural fracture and the horizontal plane; determining the horizontal maximum principal stress direction; determining the in-situ three-directional principal stress; determining the poroelastic constant and the formation fluid pressure; determining the natural fracture approaching angle; determining the unit normal vector of the three-dimensional natural fracture surface; determining the normal stress and the shear stress of the three-dimensional natural fracture surface; determining the effective stress; and determining the inner friction coefficient of the spatial natural fracture. The application considers that the natural fracture in the underground reservoir is spatially distributed, and is kept in static mechanical balance under the joint action of the in-situ stress field and the formation fluid. The application obtains the calculation method of the inner friction angle of the three-dimensional natural fracture in space in the rock mass containing the natural fracture medium by using a mathematical method, fills the blank of the method for obtaining the inner friction coefficient of the three-dimensional natural fracture in space, and can show the influence of the strike and the dip angle of the natural fracture on the inner friction coefficient of the fracture surface.

The application provides a method and device for evaluating the safety of liquefiable foundation of offshore wind turbine with single pile foundation, which can be applied to the technical field of offshore wind turbine single pile foundation. The method comprises the following steps: based on the load combination of the single pile foundation in the target working condition of the offshore wind turbine structure, the dynamic response of the offshore wind turbine structure is simulated by using a numerical model to obtain the excess pore water pressure ratio and effective stress of the foundation soil embedded by the single pile foundation; in the case that the excess pore water pressure ratio represents the deterioration of the foundation soil, the soil parameters of the deteriorated foundation soil are determined according to the excess pore water pressure ratio and the effective stress; the soil parameters are updated to the soil elements of the numerical model to perform static elastoplastic analysis on the single pile foundation, and the ultimate bearing capacity of the single pile foundation in the deteriorated foundation soil is obtained; the safety factor between the mud surface load of the single pile foundation under the load combination and the ultimate bearing capacity is calculated to evaluate the bearing safety of the single pile foundation in the deteriorated foundation soil.

The application discloses an arch dam valley amplitude deformation risk quantitative early warning method and system based on plastic effective stress evolution, and the method comprises the following steps: S1, acquiring deep site monitoring data; S2, calibrating the plastic effective stress coefficient and the rock mass or structural plane strength parameter, and determining the value range of different rock masses; S3, removing the elastic volume deformation component, and directly constructing the plastic effective stress tensor for controlling the shear yield; S4, constructing the dimensionless plastic approximation degree index K, and quantifying the approximation degree of the stress state to the failure envelope surface; S5, introducing the displacement rate and the cumulative deformation for double control verification, and intelligently identifying the critical yield locking, limited plastic damage and continuous structural plane rheological mode. The application solves the mechanism paradox between the traditional theory of 'water thrust causes deformation widening' and the actual monitoring of 'valley amplitude narrowing', and realizes the accurate quantification and grading early warning of the rheological risk of the deep rock mass of the high arch dam.

A method, system, device, and readable storage medium for predicting leading-edge bulging cracks are disclosed, relating to the field of geological disaster monitoring and early warning. Specifically, the method includes determining the active thrust of the landslide on the leading edge based on the landslide mass weight, sliding surface dip angle, seepage hydrodynamics, and additional thrust, wherein the additional thrust is generated by external dynamic disturbance. When the detected active thrust is not less than the passive earth pressure limit, the target vertical bulging displacement is determined based on horizontal shear displacement, maximum dilatation angle, geometric correction factor for shear zone thickness, hydraulic correction factor, initial effective stress, real-time effective stress, and dilatation angle stress sensitivity factor. The predicted leading-edge bulging crack result is determined based on the target vertical bulging displacement and the predicted vertical bulging displacement. This application can improve the accuracy and applicability of leading-edge bulging crack prediction.

The invention relates to the technical field of oil exploration, in particular to a method and device for measuring and analyzing the total porosity of deep coal rock. The method comprises the following steps: preparing a deep coal rock core sample of a target work area; measuring the deep coal rock core sample under different effective stresses to obtain the total porosity of the deep coal rock core sample; establishing a function equation of the total porosity and the effective stress based on the total porosity and the corresponding effective stress of the coal rock core sample measured under different effective stresses; and obtaining the total porosity of the deep coal rock of the target work area based on logging information of the target work area and the functional equation. The method mainly aims at a coal rock stratum, has higher precision compared with a previous method, and can provide necessary parameters for deep coal rock gas exploration dessert evaluation, reserve submission and the like.

The application is suitable for the technical field of earth pressure balance shield tunneling safety, and provides a shield soil cabin pressure control method in a pneumatic auxiliary tunneling mode, which comprises the following steps: obtaining the vertical effective stress distribution of the soil in the soil cabin according to the gas, solid and liquid three-phase volume percentages, pore water pressure and air pressure of the foam improved spoil, and considering the compressibility and unsaturation thereof; determining the air-soil mixed pressure distribution in the soil cabin according to the air-soil interface height in the soil cabin; determining the air-soil mixed pressure distribution at the next moment according to the screw conveyor speed, shield tunneling speed and air pressure loss amount in the soil cabin; and adjusting the shield tunneling speed and screw speed so that the air-soil mixed pressure resultant force in the soil cabin is between the active soil pressure resultant force and the passive soil pressure resultant force of the excavation stratum. The application can improve the control precision of the air-soil mixed pressure in the shield soil cabin in the pneumatic auxiliary tunneling mode.

The invention discloses a method and a device for evaluating lateral sealing performance of a shale gas reservoir in lifting stages. The method comprises the following steps: acquiring initial reference data of the shale gas reservoir and lifting response data of each lifting stage; dividing the target area into a plurality of geologic structure units and meshing the geologic structure units, and coupling multi-physical field coupling equations in each grid, including a stress equation, a physical property equation constructed based on initial reference data and lifting response data, and a gas seepage equation; iteratively solving a multi-physics field coupling equation, outputting grid effective stress and grid lifting amplitude after processing of a stress equation, outputting grid porosity and grid permeability after processing of a physical property equation, and outputting gas mass flux after processing of a gas seepage equation; and determining the maximum lateral sealing distance of each geological structure unit according to the gas mass flux and the grid permeability, then calculating a sealing coefficient, and evaluating the lateral sealing property of each geological structure unit of the shale gas reservoir in the lifting stage. According to the method, accurate and quantitative evaluation of the lateral sealing performance in the lifting stage can be realized.

This invention provides a quantitative calculation method for the multi-factor causes of abnormal low pressure in oil reservoirs, including: calculating the formation pressure P after uplift time t based on the formation temperature, pressure, overlying strata pressure, and effective stress coefficient before uplift; the formation temperature, formation pressure, overlying strata pressure, formation compaction coefficient, and effective stress coefficient at time t during the uplift process; the thermal expansion coefficient and compressibility coefficient of petroleum; and the petroleum residual coefficient after light hydrocarbon loss. Pt The calculation formula; based on the pressure value P Pt The calculation formula uses the controlled variable method to quantitatively calculate the influence of multiple controlling factors during the tectonic uplift period on the current abnormally low pressure P. Pt The relative contribution of the resulting erosion is determined by various controlling factors, including uplift erosion, temperature reduction, and dissolution. The method provided by this invention has wider applicability and greater practicality than previous methods, and possesses certain industrial application value.