Systems and methods for determining shear failure of a rock formation are disclosed. The method includes receiving, by a processor, a plurality of parameters related to physical properties of the rock formation, applying the plurality of parameters to a predetermined failure criterion, and determining shear failure of the rock formation based on the failure criterion. In some embodiments the failure criterion is a modified Hoek-Brown failure criterion that takes into consideration an intermediate principal stress, and the difference between normal stresses and an average confining stress.

A method for characterizing complexity of rock fracture based on fractal dimension and a device thereof are provided. The method includes steps of: collecting rock fracture samples of a rock, and collecting basic parameters of the rock; determining a fractal dimension of a rock fracture morphology of the rock; calculating the fractal dimension of the rock; calculating a complexity coefficient Fc of rock fracture of the rock; and characterizing a complexity of rock fracture of the rock based on the complexity coefficient Fc of rock fracture of the rock. In the present invention, combined with the fractal geometry theory, fracture complexity coefficient of shale rocks is redefined and calculated to accurately characterize rock fracture morphology, so that characteristics of rock fracture morphology is correctly understood and affecting factors of fracture morphology is analyzed.

A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

Monitoring and diagnosing completion during hydraulic fracturing operations provides insights into the fracture geometry, inter-well frac hits and connectivity. Conventional monitoring methods (microseismic, borehole gauges, tracers, etc.) can provide a range of information about the stimulated rock volume but may often be limited in detail or clouded by uncertainty. Utilization of DAS as a fracture monitoring tool is growing, however most of the applications have been limited to acoustic frequency bands of the DAS recorded signal. In this paper, we demonstrate some examples of using the low-frequency band of Distributed Acoustic Sensing (DAS) signal to constrain hydraulic fracture geometry. DAS data were acquired in both offset horizontal and vertical monitor wells. In horizontal wells, DAS data records formation strain perturbation due to fracture propagation. Events like fracture opening and closing, stress shadow creation and relaxation, ball seat and plug isolation can be clearly identified. In vertical wells, DAS response agrees well with co-located pressure and temperature gauges, and illuminates the vertical extent of hydraulic fractures. DAS data in the low-frequency band is a powerful attribute to monitor small strain and temperature perturbation in or near the monitor wells. With different fibered monitor well design, the far-field fracture length, height, width, and density can be accurately measured using cross-well DAS observations.

A numerical simulation and parameter optimization method for volumetric fracturing of an unconventional dual medium reservoir includes the following steps: based on the theory of dual-medium pore elasticity, in consideration of the friction effect between fractures, developing a viscoelastic-plastic damage model of hydraulic fractures based on explicit time integral; simulating random intersection and bifurcation of hydraulic fractures encountering with natural fractures by adopting a method of embedding zero-thickness fracture units in the inner boundaries of computational model grids, and establishing a mathematical model of hydraulic fracture expansion of volumetric fracturing in the unconventional dual-medium reservoir; compiling a finite element program for complex multi-fracture fracturing and competitive expansion during volumetric fracturing of the unconventional reservoir, and establishing a hydraulic fracturing finite element model of a casing-cement ring-perforation hole in cluster-reservoir matrix containing natural fractures.

This disclosure describes systems, methods, and apparatuses for preventing wireline sticking during hydraulic fracturing operations, the system comprising: a sensor coupled to a fracking wellhead, circulating fluid line, or standpipe of a well and configured to convert acoustic vibrations measured in fracking fluid in the wellhead, fluid line, or standpipe into an electrical signal in a time domain; a memory configured to store the electrical signal; a converter configured to access the electrical signal from the memory and convert the time domain electrical signal into a frequency domain spectrum; a machine-learning system configured to classify the current frequency domain spectrum as associated with increasing wireline friction, the machine-learning system trained on previous frequency domain spectra measured during previous wireline operations and previously classified by the machine-learning system; and a user interface configured to return an indication of the increasing wireline friction to an operator of the hydraulic fracturing operations.

Methods may include creating a fracture set from a collection of intersecting fractures in a borehole image log recorded within a subterranean formation; classifying the fracture set into groups of fully and partially intersecting fractures; calculating one or more of the elongation ratio and the rotation angle of the partially intersecting fractures; determining a probability of full intersection of fractures from the fracture set; and determining a fracture size or a parametric distribution of fracture sizes from the fracture set using the calculated one or more of the elongation ratio and the rotation angle and the determined probability of full intersection of formation fractures within the borehole.

A system, computer-readable medium, and method for determining a potential drilling location, of which the method includes obtaining data representing a subterranean domain. The data includes at least seismic data. The method also includes inverting the seismic data, creating a petroleum systems model of the subterranean domain based at least in part on a result of inverting the seismic data, simulating a dynamic reservoir model of the subterranean domain based at least in part on the petroleum systems model, and identifying the potential drilling location based on a combination of the inverting of the seismic data, creating the petroleum systems model, and simulating the dynamic reservoir model.

Methods, systems, devices, and products for well logging. Methods include conveying a logging tool in the borehole on a carrier; obtaining a borehole image over at least one interval of borehole depth from well logging measurements with a downhole imaging instrument; obtaining acoustic information representative of acoustic reflections from a far-field region of the formation; obtaining quantitative borehole fluid information indicative of properties of a formation fluid in a near-field region of the borehole; generating a borehole connectivity fracture model of the formation in dependence upon the borehole image, the quantitative borehole fluid information, and the acoustic information. Methods may include identifying near-field fractures from the borehole image, and/or identifying far-field fractures from the acoustic information. Methods may include generating a fracture interpretation correlating the near-field fractures with the far-field fractures, and generating the borehole connectivity fracture model of the formation in dependence upon the fracture interpretation.

Systems and methods for generating candidate designs and selecting a fracturing position design scheme for a horizontal well to be fractured based on fracturing potential are disclosed. A fracturing potential value of each designed fracturing point or each fracturing point is calculated using obtained values of various indexes of various depth points. A first corresponding relation between fracture conductivity value and the fracturing potential value and a second corresponding relation between a fracture half length and the fracturing potential value is determined. Corresponding first simulated production data for each candidate design is generated, and the candidate design with a highest predicted net present value is selected as the fracturing position design scheme which provides higher rationality and practicability to better guide development.