100 results about "Differential stress" patented technology

A method for optimizing hydraulic fracturing simulates the geomechanical interaction between regional stress and natural fractures in a reservoir. An equivalent fracture model is created from data on the natural fracture density, regional stress and geomechanical properties of the reservoir, so that points in the reservoir are assigned a fracture length and fracture orientation. The horizontal differential stress and maximum principal stress direction at points in the reservoir are then estimated by meshless particle-based geomechanical simulation using the equivalent fracture model as an input. The meshless particle-based geomechanical simulator uses the derived initial geomechanical condition to simulate the sequence of hydraulic fracturing and derive the resulting strain and J integral that can be used to estimate the asymmetric half fracture lengths and initial propped permeability needed by hydraulic fracturing design and reservoir simulation software to optimize wellbore and completion stage positions.

This invention relates to methods of inducing differential stress resistance in a subject with cancer by starving the subject for a short term, administering a cell growth inhibitor to the subject, or reducing the caloric or glucose intake by the subject. The induced differential stress resistance results in improved resistance to cytotoxicity in normal cells, which, in turn, reduces cytotoxic side-effects due to chemotherapy, as well as improved effectiveness of chemotherapeutic agents.

Method for constructing an integrated rock physics model that simulates both shale anisotropy and stress-induced anisotropy of clastic rocks. In the model, the total pore volume is divided into three parts according to the estimated shale volume and effective stress: (1) clay-related pores, (2) sand-related pores, and (3) microcracks (mainly in the sand component). The pore space is then partitioned into the clay-related and sand-related pores using a scheme first disclosed by Xu and White in 1995. The model simulates shale anisotropy via the preferred orientation of clay-related pores and stress-induced anisotropy via the preferred orientation of microcracks, which is controlled by the differential stresses. Laboratory measurements or well logs are needed to establish a relationship between crack density and the effective stress.

The invention provides a method for quantitatively determining the brittle-ductile critical condition of gypsum rock-carbonatite. The method comprises the steps that the gypsum rock-carbonatite is adopted as a sample, and the sample comprises the lithological characters of gypsum containing dolomite, gypseous dolomite, dolomite-quality gypsum rock and dolomite containing gypsum rock; temperature and pressure of a critical construction period of petroleum entrapment evolution according to the history of structural evolution of a basin where the gypsum rock-carbonatite is located, and are adopted as temperature and pressure of experimental simulation; the maximum differential stress value and the maximum inflection point stress point of the sample are measured under simulation temperature and pressure respectively; the critical position of conversion of the brittleness and tenacity of the sample is quantitatively evaluated according to the maximum differential stress value and the maximum inflection point stress point of the sample, and the brittle-ductile critical condition of the gypsum rock-carbonatite is quantitatively determined. According to the method, the brittle-ductile critical condition of the gypsum rock-carbonatite can be accurately evaluated, and a basis is provided for accurately evaluating and predicting petroleum entrapment of the gypsum rock-carbonatite.

The invention discloses a method for measuring two-dimensional stress at a weld joint by using a Barkhausen effect and a detection instrument. A ferrite magnetic core and a magnetic core of a Barkhausen measuring probe are directly contacted with the surface of the weld joint of the test piece, so that the X-direction tangential stress and the Y-direction axial stress of the weld joint of the test piece are calibrated; the Barkhausen measuring probe is used for collecting excitation signals and detecting Barkhausen signals, stress signal amplitude waveforms are obtained, and signal amplitude noise is obtained according to the waveforms; a Barkhausen noise signal amplitude is extracted from a signal detected by the Barkhausen measuring probe, the Barkhausen noise signal amplitude continuously changes along with the tension and pressure stress values to form a tension and pressure fitting curve, and the tension and pressure fitting curve serves as a calibration result of the relation between the Barkhausen noise signal amplitude and the continuous tension and pressure stress; and finally, a Barkhausen noise signal, the residual stress sigma1 in the vertical direction, the residual stress sigma2 in the parallel direction and the quantitative relation of the included angle theta between the main stress direction and the magnetic field direction are obtained, and the two-dimensional residual stress of the welding area is directly detected.

The invention provides a method for preparing an amorphous alloy bulk material. The preparation method adopts amorphous alloy powder as a raw material, and the characteristics of viscosity decrease and gradual softening of amorphous alloy with the increase of the temperature and the characteristic of superplasticity of the amorphous alloy in a supercooled liquid region are combined with the characteristics of rapid particle acceleration, low heating temperature, small heat influences, difficult oxidation and microstructure change, small thermal stress and final compressive stress state in thecold spraying process and the optimization control of process parameters to achieve high-speed bumping deposition of the particles layer by layer in order to form the he bulk material; and the impactof the subsequent particles has a compacting and densifying effect on formed deposits in a range of sizes of several particle thicknesses. The method has the technical advantages of simple process, short production cycle, low processing cost, strong adaptability, and unlimited size of the material.

Disclosed herein are various methods and structures using contacts to create differential stresses on devices in an integrated circuit (IC) chip. An IC chip is disclosed having a p-type field effect transistor (PFET) and an n-type field effect transistor (NFET), a PFET contact to a source / drain region of the PFET and an NFET contact to a source / drain region of the NFET. In a first embodiment, a silicon germanium (SiGe) layer is included only under the PFET contact, between the PFET contact and the source / drain region of the PFET. In a second embodiment, either the PFET contact extends into the source / drain region of the PFET or the NFET contact extends into the source / drain region of the NFET.

The invention provides a method for prolonging the fatigue life of a complex structure of a crude oil transfer barge. The method comprises the following steps: step 110, establishing a full-random fatigue life prediction model; 120, collecting a 3D model of a target complex structure, determining positions and sizes of all drain holes of the 3D model, and inputting the 3D model into the full-random fatigue life prediction model to obtain a related prediction result; 130, determining drain holes with stress concentration according to related prediction results; and step 140, adjusting the position and the size of the drain hole with stress concentration, and paying attention to the adjusted prediction result in real time until the stress concentration problem is solved. According to the method, stress concentration can be effectively reduced by adjusting the position of the drain hole in the structural design. Meanwhile, residual compressive stress is further formed by using a laser shock peening method, and the fatigue life of a complex structure is prolonged.

A method for minimizing the risk of induced seismicity from injection of fluids into a naturally fractured reservoir uses a meshless particle-based simulation to quantify the heterogeneity in energy storage within the reservoir. In particular, this methodology creates an equivalent fracture model from data on the natural fracture density, regional stress, pore pressure and elastic properties of the reservoir, in which points in the reservoir have a fracture length and fracture orientation. A meshless particle-based method is then employed to simulate the geomechanical interaction between regional stress and natural fractures to estimate the stress anisotropy and strain (e.g., differential stress and shear strain). The induced seismicity potential is then calculated at points in the reservoir based on the estimated stress anisotropy and strain. A zone for injection of fluids into the reservoir can be selected by identifying a large area of the reservoir having low induced seismicity potential.