71 results about "Nondimensionalization" patented technology

The invention discloses a method for evaluating compressibility of a tight reservoir based on a stress-strain curve. The method comprises the following steps: testing the stress-strain curve of a rocksample under a certain confining pressure to obtain elasticity modulus and Poisson's ratio of an elastic deformation stage so as to obtain the volumetric strain of the elastic deformation stage and obtain crack volume strain; determining an expansion point of the rock sample according to an axial strain-crack volume strain relationship curve and obtaining the strain energy size through the stress-strain curve envelope area formed from the expansion point to the break point in an enclosing way; and establishing a compressibility index mathematical model of the surrounding rock by performing nondimensionalization on the change numerical value of the parameter, and calculating and comparing the size. The experimental evaluation method provided by the invention is suitable for the unconventional resources such as shale gas, coal bed gas, compact oil gas and a hot dry rock, and can be applied to the conventional oil and gas reservoir with low permeability and ultralow permeability. The confining pressure effect is considered and the artificial fracture density formed after the rock is expanded is considered, so the method can be used for evaluating the artificial joint network formingcapability of the formation condition and guiding the volumetric fracturing construction to select wells and select formations.

The invention discloses a rail passenger flow congestion risk evaluation method based on an entropy weight. The method comprises: acquiring monitoring values of two characteristic indexes, namely an in-out station passenger flow volume and a load factor, of a rail station section at different durations; respectively nondimensionalizing a forward index and a reverse index by utilizing different membership functions, uniformly transforming an evaluation value of each index to be a quantified numeric value in a range [0, 1], and eliminating nondimensionalization influence; calibrating model parameters by taking maximum values of the indexes within the statistic time as input values of a model; and calculating weights of different evaluation indexes in the model according to an entropy weight method, clustering risk evaluation, and partitioning grades of rail passenger network passenger flow congestion five-stage risk. The method provided by the invention constructs a rail passenger network operation passenger flow congestion risk evaluation model and quantitatively evaluates the whole rail passenger network operation passenger flow congestion risk based on the in-out station passenger flow volume and the load factor of the rail station section.

The invention relates to a method for quantitatively forecasting analog development indexes of oil and gas fields. The method comprises the following steps that 1), an oil pool three-dimensional seepage mathematic model is built according to a motion equation, a matter balance equation, a saturability auxiliary equation, initial conditions and boundary conditions of an oil pool; 2), nondimensionalization is carried out on the oil pool three-dimensional seepage mathematic model to obtain the nondimensionalization mode of the oil pool three-dimensional seepage mathematic model; 3), the oil pool three-dimensional seepage similarity criterions are obtained according to the equation structure and similarity theory analysis of the nondimensionalization mode of the oil pool three-dimensional seepage mathematic model and are simplified into pi I and pi II; 4), whether the oil and gas fields to be developed and the developed oil and gas fields meet the similarity criterions pi I and pi II or not is judged; 5), for the oil and gas fields meet the similarity criterions pi I and pi II, to-be-developed productivity Q and to-be-developed recovery efficiency R of the developed oil and gas fields are forecasted according to developed productivity Q and developed recovery efficiency R of the developed oil and gas fields by using a forecast formula; 6), the quantitative forecast result of to-be-developed productivity Q and to-be-developed recovery efficiency R of the oil and gas fields to be developed in the development indexes can be obtained through calculation.