7 results about "Repeated fractures" patented technology

The invention discloses a method for predicting the service behavior of an oil and gas pipeline under a stress corrosion cracking condition, and belongs to the field of material performance analysis and prediction. Firstly, based on a convection diffusion equation, a real stress intensity factor of an oil and gas pipeline crack tip is used as an unknown quantity to obtain a stress distribution condition; then, applying boundary conditions and a crack propagation criterion in fracture mechanics, and performing preliminary calculation to obtain crack propagation behavior characteristics of the one-dimensional semi-analytical model; and finally, calibrating and calculating the diffusion coefficient of the material parameter in the one-dimensional semi-analytical model to obtain real full-life service time information of the oil and gas pipeline material. According to the method, the full-life behavior information of stress corrosion cracking can be quickly obtained, and a partial differential equation does not need to be solved; on the basis of fracture mechanics, the mechanism of repeated fracture and reconstruction of the passivation layer in the fracture process can be reproduced; the full-life service time of the oil and gas pipeline can be effectively predicted, and the parameter calibration method can be applied to other conditions and is wide in application range.

The invention discloses a preparation method of a growth factor gradient bionic scaffold for tendon-bone interface regeneration and repair, and belongs to the technical field of biomedical materials. The composite scaffold is constructed by adopting a coaxial electrospinning and self-assembly technology, and is compounded by a core-shell oriented nanofiber layer and a non-oriented nanofiber layer through a gelatin adhesive to respectively simulate tendon phase and bone phase structures of a tendon-bone interface; a shell layer of the tendon-phase-simulated core-shell oriented nanofiber is a PCL layer containing CTGF, a core layer of the tendon-phase-simulated core-shell oriented nanofiber is a PVA layer containing TGF-beta1, and a bone-phase-simulated non-oriented nanofiber layer is a PCL / Gel co-spun layer containing BMP-2 polylactic acid microspheres and nano-hydroxyapatite. The scaffold can realize secondary controlled release of early-stage release of CTGF, slow release of TGF-beta1 in the middle and later periods and continuous release of BMP-2, and cooperates with a fiber orientation structure to induce graded differentiation of mesenchymal stem cells and promote integrated repair of a tendon-bone interface gradient structure, so that the problems of poor healing of a tendon-bone interface and high repeated fracture rate in a traditional repair method are solved, and the scaffold has good application prospects. The important application value is realized in the field of tendon-bone injury treatment in sports medicine.

The application discloses a fracturing parameter optimization method and system based on repeated fracturing fracture morphology, belongs to the technical field of overall repeated reconstruction of old oilfield blocks, and comprises the following steps: first, obtaining seismic source positioning information; then, in combination with the seismic source positioning information, obtaining seismic source fracture length, fracture width, fracture height, fracture branch index, fracture network length, apparent stress, stress index, diffusion index and plasticity index; based on the above parameters, obtaining fracturing results of a remaining oil enrichment area; and according to the fracturing results of the remaining oil enrichment area, adjusting construction parameters to realize fracturing parameter optimization of the repeated fracturing fracture morphology. Therefore, the optimization method solves the problems in the prior art, can realize evaluation of fracturing effects by using interpretation results of microseismic monitoring data, optimization of hydraulic fracturing design, and ultimately, on the basis of the repeated fracturing fracture morphology and the fracture parameters, optimization of an old oilfield repeated fracturing effect evaluation method and formation of a parameter system.

The present application relates to the technical field of well repair operation, in particular to a horizontal well wellbore reconstruction and repeated fracturing process method.The process method of the present application is integrated with fracture leakage reduction, wellbore reconstruction and soluble bridge plug multi-layer fracturing technology, and a new technology for precise repeated fracturing reconstruction of horizontal wells is proposed, which mainly injects leakage reduction agent into the original fracture through the tubing to temporarily block the original fracture, and then performs staged fracturing after cementing the wellbore reconstruction pipe column from the tubing, and one pipe column is used to complete all the layers that need to be reconstructed, which meets the requirements of horizontal well reconstruction, large displacement, large sand volume, large liquid volume and precise target layer fracturing, thereby improving the development effect of old oil fields.

The present specification provides a method and device for determining an energy accumulation and repeated fracturing mode. The method comprises: performing different modes of energy accumulation and repeated fracturing on a sealed target core sample, the target core sample having initial fracture characteristic data; determining a fracture zone of the target core sample after the different modes of energy accumulation and repeated fracturing and extracting target fracture characteristic data of the fracture zone; determining comprehensive fracture characteristic data according to the initial fracture characteristic data and the target fracture characteristic data, the comprehensive fracture characteristic data being used to determine fracturing effects of the different modes of energy accumulation and repeated fracturing; comparing the comprehensive fracture characteristic data and selecting a target energy accumulation and repeated fracturing mode according to a comparison result. Based on the above method, an optimal energy accumulation and repeated fracturing mode can be selected, guidance can be provided for fracturing sites, and oil well productivity can be improved.

The application discloses a repeated fracturing method for a high-water-cut horizontal well in a low-permeability reservoir, which comprises the following steps: performing a repeated fracturing seam design on the high-water-cut horizontal well, determining a high-water-yielding fracture of the high-water-cut horizontal well in a target block, determining a safety distance S of the high-water-yielding fracture and an adjacent fracturing fracture, performing the seam design according to the principle that the distance of the high-water-yielding fracture and the adjacent fracturing fracture along the wellbore direction is greater than the safety distance S, and determining the safety distance S according to the maximum horizontal stress direction of the target block, judging the predicted extension direction of the high-water-yielding fracture, and determining the safety distance S based on the included angle alpha between the extension direction and the wellbore. The method solves the problem that the existing repeated fracturing construction of the high-water-cut horizontal well in the low-permeability reservoir easily leads to water flooding.

The invention belongs to the field of oil reservoir development, and particularly relates to a horizontal well pre-fracturing energy supplement refracturing physical simulation experiment device which comprises a mold, two first splinters are arranged in the mold, a second splinter is arranged in the mold, and the size of the first splinters is larger than that of the second splinter. The device further comprises a plurality of independent pipelines, one ends of the pipelines are embedded into the cracks of the first split piece and the second split piece respectively, the other ends of the pipelines extend out of the mold and are connected with a power source, the concentration of fluid flowing through the second split piece is higher than that of fluid flowing through the first split piece, and valves and first monitoring units are arranged on the pipelines. The first monitoring unit is arranged along the length direction of the pipeline, the second monitoring unit is arranged along the length direction of the pipeline in the mold, cement is poured into the mold to form a simulation block, and a driving source is arranged outside the simulation block. And more experimental bases are provided for refracturing scheme design of oil fields and scientific research institutions.