7 results about "Multiple fracture" patented technology

The invention discloses a tight sandstone shear wave prediction method based on a fluid saturation dual fracture coupling model, and relates to the technical field of earth exploration physics. According to the method, a saturated rock physical model containing two groups of vertical orthogonal fracture fluids is constructed based on a Chapman multi-scale fracture medium theory framework, and an inter-fracture fluid mass distribution function is introduced to construct a dual-fracture coupling model based on fluid saturation. According to the method, conventional logging information is used as prior information, a rock physical model is used as a drive, an actual longitudinal wave speed and a simulated transverse wave speed are used as nested constraint conditions, a transverse wave speed prediction objective function is constructed, the tight sandstone transverse wave speed and the reservoir multi-group fracture density are estimated, a simulated annealing particle swarm optimization algorithm is introduced, and the reservoir multi-group fracture density is predicted. And the global optimization capability and the local convergence efficiency are enhanced. According to the method, the shear wave velocity prediction error can be effectively reduced, meanwhile, reservoir microstructure parameters are provided, and effective support is provided for reservoir fluid property judgment, lithology accurate recognition and underground fracture system quantitative description.

This invention relates to the field of oil and gas reservoir geological exploration technology, specifically a method for identifying multiple fracture stages in buried hill oil and gas reservoirs based on tectonic stress field evolution. The method includes the following steps: Tectonic evolution history analysis step: Geological data of the target buried hill oil and gas reservoir area are systematically collected. Based on seismic profiles, stratigraphic contact relationships, tectonic deformation characteristics, and chronological data, a comprehensive analysis is conducted to construct a multi-stage tectonic evolution history of the area from the Paleozoic to the Cenozoic, accurately determining the geological age and tectonic nature of each key tectonic event. Compared to existing technologies, this application establishes a quantitative discrimination model based on mechanical principles through paleostress field numerical simulation and quantitative prediction of theoretical fracture parameters. This standardizes and quantifies the fracture stage identification process, significantly reducing the uncertainty caused by human factors, improving the objectivity and repeatability of the discrimination results, and achieving a leap from qualitative analysis to quantitative discrimination.

The invention discloses an automatic plugging device and method for a regeneration crack of a roadway protection coal pillar, and the device comprises a plurality of groups of grouting systems which are respectively installed in drill holes of a coal wall; the slurry supply system is connected with the conveying pipeline system; a plurality of groups of pressure monitoring systems are arranged; the slurry supply system and the pressure monitoring system are connected with the control system; the audible and visual alarm is connected with the control system; a liquid level detection unit is installed in the slurry supply system, and an electric ball valve is arranged on the conveying pipeline system. The method can effectively cope with expansion of multiple fractures of the coal pillar caused by mining-induced stress, can automatically perform grouting and plugging, reduces the construction times of coping with regenerated fractures, and reduces the drilling construction cost.

This invention discloses a coalbed methane fracturing fluid system and a method for balanced propagation of multiple fractures, relating to the field of coalbed methane extraction technology. The coalbed methane fracturing fluid system includes a main fluid base as the transport medium, ceramic particles as proppant, coated heat-generating microcapsules, and a self-responsive diverting agent. The core material of the heat-generating microcapsules is a solid substance that releases heat upon contact with water. Its coating layer has temperature-responsive characteristics, softening and rupturing when a temperature threshold is reached, releasing heat to reduce the viscosity of the fracturing fluid. The self-responsive diverting agent has a core-shell structure; its outer shell hydrolyzes at specific temperatures and pH levels, causing the core elastomer to absorb water and expand. It can selectively and autonomously seal wide fractures according to the fracture width, guiding the fracturing fluid to narrower, less expanded fractures. The method includes: first, injecting a pre-fluid containing coated heat-generating microcapsules; then adding proppant and diverting agent and pumping sand-carrying fluid; finally, shutting in the well and controlling flowback. This optimizes fracture conductivity, promotes balanced propagation of multiple fractures, and improves extraction efficiency.

The invention discloses a carbonate rock crack modeling method based on digital outcrop and geomechanical simulation. According to the method, firstly, a high-precision digital outcrop model is constructed through unmanned aerial vehicle oblique photography, outcrop surface crack parameters are obtained, and crack groups are divided; and determining the ancient stress field characteristics of multiple fracture forming periods by combining filler isotope test and acoustic emission experiment. And further, carrying out geomechanical simulation based on the recovered paleostructure, and quantitatively calculating the density and opening parameters of the crack in each stage by utilizing a two-stage fracture criterion and a strain energy density theory. And then, a deterministic modeling technology and a random modeling technology are fused, a multi-stage and multi-scale discrete fracture network model is constructed, and fluid simulation is performed based on the model so as to analyze the control effect of the fracture on the ancient karst. And finally, through comparison verification with outcrop measured data, the corrected crack-matrix coupling prototype geologic model is output, quantitative prediction of the cracks in the outcrop is realized, and the precision and reliability of the crack prototype model are remarkably improved.

The invention relates to the technical field of oil and gas reservoir geological exploration, in particular to a buried hill oil and gas reservoir multi-stage crack stage judgment method based on tectonic stress field evolution, which comprises the following steps: a tectonic evolution history analysis step: a system collects geological data of a target buried hill oil and gas reservoir area; based on a seismic profile, a stratum contact relation, tectonic deformation characteristics and chronology data, a multi-period tectonic evolution history of the region from ancient generations to neonatology is comprehensively analyzed and constructed, and the geological age and the tectonic property of each key tectonic motion event are accurately determined. Compared with the prior art, the method has the advantages that a quantitative judgment model based on the mechanical principle is established through paleostress field numerical simulation and theoretical crack parameter quantitative prediction, so that the crack period judgment process is standardized and quantified, the uncertainty caused by human factors is greatly reduced, the objectivity and repeatability of a judgment result are improved, and the method is suitable for popularization and application. And the crossing from qualitative analysis to quantitative discrimination is realized.

The invention discloses a fracturing transformation effect analysis method and device. The method comprises the steps that a wellhead pressure curve obtained after fracturing transformation is conducted on a shale gas well is obtained; according to the wellhead pressure curve, the pressure fluctuation frequency and the pressure fluctuation amplitude of the multiple fracturing sections are determined; projecting the pressure fluctuation frequencies and the pressure fluctuation amplitudes of the plurality of fracturing sections to a preset evaluation chart; according to projection results of the pressure fluctuation frequencies and the pressure fluctuation amplitudes of the plurality of fracturing sections on the evaluation chart, determining fracturing transformation effects of the plurality of fracturing sections; the fracturing transformation effect reflects the complexity of a fracture network formed by fracturing transformation, a fracturing transformation effect analysis technical scheme which is simple in operation process, low in cost and high in timeliness can be provided, the analysis accuracy is improved, and the requirement for accurately and rapidly evaluating the fracturing transformation effect on an oil field site is met.