Abstract: A high-throughput microstructure characterization and reconstruction method of heterogeneous materials is provided. By extracting the features such as content, size and morphology of each constituent phase in the microscopic image of heterogeneous materials, and combining the principles of physical descriptor and texture synthesis method, the constituent phase with 10 microns scale, regular geometrical morphology and low content is characterized and reconstructed based on the physical descriptor, and the constituent phase with 100 microns scale, complex geometrical morphology and high content is characterized and reconstructed based on texture synthesis, and then the composition is adjusted to compensate for the overlapping pixels of each constituent phase to obtain batch reconstructed images.

Abstract: The present invention discloses a method for realizing uniform stimulation for the oil and gas well by low-cost multi-stage fracturing, comprising the following steps: first calculate and predict the inlet widths of the fracture created in the planned hydraulic fracturing; then design the plugging scheme for blocking the fracture inlet after each fracturing treatment; the selected plugging particles are composed of filling particles and skeleton particles, with designed plugging scheme; after complete the design of plugging scheme, perform the fracturing treatment to create hydraulic fracturing in the reservoir; skeleton particles and filling particles are added into the fractures successively according to plan. The present invention provides a multi-stage single-cluster fracturing method, with the advantages of controllable fracture sizes and low cost. The present invention can realize a good uniformity of stimulation for the oil and gas wells.

Abstract: The present invention discloses a method for realizing uniform stimulation for the oil and gas well by low-cost multi-stage fracturing, comprising the following steps: first calculate and predict the inlet widths of the fracture created in the planned hydraulic fracturing; then design the plugging scheme for blocking the fracture inlet after each fracturing treatment; the selected plugging particles are composed of filling particles and skeleton particles, with designed plugging scheme; after complete the design of plugging scheme, perform the fracturing treatment to create hydraulic fracturing in the reservoir; skeleton particles and filling particles are added into the fractures successively according to plan. The present invention provides a multi-stage single-cluster fracturing method, with the advantages of controllable fracture sizes and low cost. The present invention can realize a good uniformity of stimulation for the oil and gas wells.

Abstract: The present invention discloses a method for evaluating fracture connectivity and optimizing fracture parameters based on complex network theory, comprising the following steps: obtaining natural fracture distribution laws and characteristic parameters of the formation based on previous knowledge of natural fractures in the formation and statistical analysis of fractures in the core, and establishing a discrete fracture network model of natural fractures based on the previous step; setting up hydraulic fractures, determining intersection relations in the fracture network and coordinates of intersection points of fractures: converting the actual fracture network into a complex network dual topology diagram based on complex network theory, and calculating evaluative indexes of the complex network to realize the evaluation of fracture network connectivity; changing the hydraulic fracture parameters to get the evaluation indexes of different hydraulic fracture schemes.

Abstract: The present invention discloses a method for evaluating fracture connectivity and optimizing fracture parameters based on complex network theory, comprising the following steps: obtaining natural fracture distribution laws and characteristic parameters of the formation based on previous knowledge of natural fractures in the formation and statistical analysis of fractures in the core, and establishing a discrete fracture network model of natural fractures based on the previous step; setting up hydraulic fractures, determining intersection relations in the fracture network and coordinates of intersection points of fractures; converting the actual fracture network into a complex network dual topology diagram based on complex network theory, and calculating evaluative indexes of the complex network to realize the evaluation of fracture network connectivity; changing the hydraulic fracture parameters to get the evaluation indexes of different hydraulic fracture schemes.

Abstract: The present invention discloses an optimized design method for a temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells, which comprises the following steps: calculating a particle size and a volume range of a candidate temporary blocking agent in an applicable target area; establishing a hydraulic fracture expansion calculation model with complete fluid-solid coupling; calculating an optimal average particle size required for effective temporary blocking; determining the particle size distribution of the temporarily blocked particles according to the optimal average particle size; calculating the particle volume of the temporary blocking agent required for effective temporary blocking; and predicting and evaluating a fracturing effect after the preferred temporary blocking design is adopted in the target area.

Abstract: The present invention discloses a method for evaluating and preventing creep damage to conductivity of hydraulic fracture in gas reservoirs, comprising: (1) selecting a rock sample of target reservoir for creep experiment, and plotting ?-t curve of the rock sample during creep; (2) fitting the fractional Kelvin model with the ?-t curve of the rock sample during creep; (3) calculating the conductivity and permeability of hydraulic fracture considering creep damage; (4) numerically solving the productivity model, calculating the cumulative gas production of the gas well produced up to time t, and calculating the creep damage rate for cumulative production of the gas well; (5) repeating Steps (3) to (4), calculating the creep damage rate for cumulative production for the cases of hydraulic fracture sanding concentration N of 5 kg/m2, 7.5 kg/m2, 10 kg/m2, 12.5 kg/m2 and 15 kg/m2 respectively, plotting the creep damage chart of cumulative production.

Abstract: The present invention discloses a method for evaluating and preventing creep damage to conductivity of hydraulic fracture in gas reservoirs, comprising: (1) selecting a rock sample of target reservoir for creep experiment, and plotting ?-t curve of the rock sample during creep; (2) fitting the fractional Kelvin model with the ?-t curve of the rock sample during creep; (3) calculating the conductivity and permeability of hydraulic fracture considering creep damage; (4) numerically solving the productivity model, calculating the cumulative gas production of the gas well produced up to time t, and calculating the creep damage rate for cumulative production of the gas well; (5) repeating Steps (3) to (4), calculating the creep damage rate for cumulative production for the cases of hydraulic fracture sanding concentration N of 5 kg/m2, 7.5 kg/m2, 10 kg/m2, 12.5 kg/m2 and 15 kg/m2 respectively, plotting the creep damage chart of cumulative production.

Abstract: The present invention discloses a process for preparing a Mannich base quaternary ammonium salt high-temperature resistant corrosion inhibitor and applications thereof. The preparation process comprises the following steps: (1) dissolve an amine substance indole, benzhydrylpiperidine, diphenylethylamine, dibenzylamine or diisopropanolamine into an organic solvent, slowly add an aldehyde substance 3-(2-thienyl)benzaldehyde or cinnamaldehyde, then place in a constant-temperature water bath, stir to react at 60-80° C.

Abstract: An optimization method for high-efficiently placing proppants in a hydraulic fracturing treatment includes steps of: (1) constructing a rock deformation governing equation during a fracturing process, and constructing a material balance equation of flowing of fracturing fluid and transport of the proppant; (2) constructing a model for representing a pumped volume fraction of the proppant; (3) calculating with given parameters, and obtaining corresponding fracture geometric size and volumetric concentration distribution of the proppant; (4) calculating a placement efficiency of the proppant for each set of parameters; (5) calculating an average placement efficiency of the proppant under different parameters; (6) selecting optimized parameters; (7) substituting the optimized parameters into the models constructed in the steps (1) and (2), calculating the placement efficiency of the proppant as step (4), and verifying whether the placement efficiency is maximum, which means the optimized parameters are optimal.

Abstract: The present invention discloses a process for preparing a dibenzylaminquaternary ammonium salt high-temperature resistant corrosion inhibitor and applications thereof. The preparation process comprises the following steps: (1) Dissolve the amine reagents benzylamine, phenethylamine, morpholine or indole in an organic solvent, slowly add epichlorohydrin dropwise, stir to react at a room temperature for 12-14 hours, and then distill under reduced pressure, and wash to obtain an intermediate I; (2) Dissolve the intermediate I in an organic solvent, add dibenzylamine at a ratio, then add an acid binding agent, warm to 60-80° C. to react for 14 to 16 hours, after cooling to room temperature, perform filtration, extraction and distillation under a reduced pressure to obtain an intermediate II; (3) Dissolve the intermediate II in an organic solvent, add quaternizing reagent at a ratio, then warm to 80-110° C.

Abstract: The present invention discloses an optimized design method for a temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells, which comprises the following steps: calculating a particle size and a volume range of a candidate temporary blocking agent in an applicable target area; establishing a hydraulic fracture expansion calculation model with complete fluid-solid coupling; calculating an optimal average particle size required for effective temporary blocking; determining the particle size distribution of the temporarily blocked particles according to the optimal average particle size; calculating the particle volume of the temporary blocking agent required for effective temporary blocking; and predicting and evaluating a fracturing effect after the preferred temporary blocking design is adopted in the target area.

Abstract: The present invention discloses a process for preparing a dibenzylaminquaternary ammonium salt high-temperature resistant corrosion inhibitor and applications thereof. The preparation process comprises the following steps: (1) Dissolve the amine reagents benzylamine, phenethylamine, morpholine or indole in an organic solvent, slowly add epichlorohydrin dropwise, stir to react at a room temperature for 12-14 hours, and then distill under reduced pressure, and wash to obtain an intermediate I; (2) Dissolve the intermediate I in an organic solvent, add dibenzylamine at a ratio, then add an acid binding agent, warm to 60-80° C. to react for 14 to 16 hours, after cooling to room temperature, perform filtration, extraction and distillation under a reduced pressure to obtain an intermediate II; (3) Dissolve the intermediate II in an organic solvent, add quaternizing reagent at a ratio, then warm to 80-110° C.

Abstract: The present invention discloses a process for preparing a Mannich base quaternary ammonium salt high-temperature resistant corrosion inhibitor and applications thereof. The preparation process comprises the following steps: (1) dissolve an amine substance indole, benzhydrylpiperidine, diphenylethylamine, dibenzylamine or diisopropanolamine into an organic solvent, slowly add an aldehyde substance 3-(2-thienyl)benzaldehyde or cinnamaldehyde, then place in a constant-temperature water bath, stir to react at 60-80° C.

Abstract: A method for optimizing perforation parameters to maintain uniform fracture growth in multi-stage hydraulic fracturing of horizontal well and device therefor are provided. The method includes steps of: S1: collecting the geological and engineering parameters of the targeted pay zone, and estimating the net inlet pressure of fractures within the targeted fracturing stage of horizontal well; S2: calculating the perforation friction coefficient required for maintaining the uniform fracture growth in multi-stage hydraulic fracturing of horizontal well; S3: calculating the perforation characteristic parameter; and S4: determining the optimized perforation parameters. The method considers the stress heterogeneity, the stress shadowing and the perforation erosion in the process of dynamic hydraulic fracturing propagation, and also the influence of perforation erosion.