A directional drilling-exploring-monitoring integrated method for guaranteeing safety of an underwater shield tunnel includes: drilling a small-diameter borehole below a water area, and establishing an initial geological model; reaming the small-diameter borehole into a large-diameter borehole, placing a parallel electrical method (PEM) power cable and a monitoring optical fiber cable into the large-diameter borehole, acquiring zero field data, primary field data and secondary field data through carbon rod measurement electrodes before tunnel excavation, and processing the data with an existing inversion method to form an inversion image, thereby obtaining a refined geological model of a stratum; starting the tunnel excavation, and respectively acquiring a disturbance condition of rock and soil and a sedimentation and deformation condition of rock and soil around the tunnel during the excavation, thereby implementing safety excavation of the tunnel; and continuously monitoring the tunnel and the surrounding rock and soil in later use of the tunnel.

Methods and systems for determining an image of a subterranean region of interest are disclosed. The method includes obtaining a seismic dataset and a geological dip model for the subterranean region of interest and determining a set of input seismic gathers from the seismic dataset. The method further includes determining a central seismic gather and a set of neighboring seismic gathers in a vicinity of the central seismic gather from the set of seismic gathers, determining a set of dip-corrected neighboring seismic gathers based, at least in part, on the set of neighboring seismic gathers and a geological dip from the geological dip model, and determining a noise-attenuated central seismic gather by combining the dip-corrected neighboring seismic gathers and the central seismic gather. The method still further includes forming the image of the subterranean region of interest based, at least in part, on the noise-attenuated central seismic gather.

A method comprises determining a measure of drilling efficiency, such as a friction factor or mechanical specific energy, of a drill bit used in a drilling operation of a wellbore and performing video analytics of at least one video that includes a substantially complete view of the wear surfaces of a drill bit to determine drill bit wear of the drill bit that is a result of the drilling operation of the wellbore. The method includes determining a cause of the drill bit wear based on the measure of drilling efficiency and the drill bit wear determined by performing video analytics. Based on correlation or modeling of drill bit wear and the measure of drilling efficiency, drill bit wear can be predicted and some types of drilling dysfunction mitigated in subsequent drilling runs.

Techniques for predicting a landing zone of a wellbore include identifying a first subsurface geological model of a first subterranean layer located under a terranean surface that includes an upper boundary depth of the first subterranean layer and a lower boundary depth of the first subterranean layer; identifying a second subsurface geological model of a second subterranean layer deeper than the first subterranean layer that is independent of the first subsurface geological model and includes an upper boundary depth of the second subterranean layer; correlating a predicted landing zone for a plurality of wellbores using the first and second subsurface geological models that is based on a location of a horizontal portion of each wellbore; and generating data that comprises a representation of the correlated plurality of wellbores for presentation on a graphical user interface (GUI).

Techniques for predicting a landing zone of a wellbore include identifying a first subsurface geological model of a first subterranean layer located under a terranean surface that includes an upper boundary depth of the first subterranean layer and a lower boundary depth of the first subterranean layer; identifying a second subsurface geological model of a second subterranean layer deeper than the first subterranean layer that is independent of the first subsurface geological model and includes an upper boundary depth of the second subterranean layer; correlating a predicted landing zone for a plurality of wellbores using the first and second subsurface geological models that is based on a location of a horizontal portion of each wellbore; and generating data that comprises a representation of the correlated plurality of wellbores for presentation on a graphical user interface (GUI).

A method for reducing water production from a hydrocarbon bearing subterranean formation includes identifying a high permeability zone in the formation and injecting a dense CO.sub.2 composition from a production well into the high permeability zone. The dense CO.sub.2 composition includes dense CO.sub.2 and a thickener soluble in the dense CO.sub.2. The thickener includes a copolymer that is the polymerized reaction product of monomers that include at least one alkenyl ether or dialkenyl ether monomer, at least one acrylate or methacrylate monomer, at least one structural monomer, and at least one allyl ester monomer. After injecting the dense CO.sub.2 composition into the high permeability zone, the method includes withdrawing hydrocarbons from the hydrocarbon bearing subterranean formation through the production well. The dense CO.sub.2 composition blocks pores in the high permeability zone to reduce or prevent flow of water from the high permeability zone into the production well.

A method for reducing water production from a hydrocarbon bearing subterranean formation includes identifying a high permeability zone in the formation and injecting a dense CO.sub.2 composition from a production well into the high permeability zone. The dense CO.sub.2 composition includes dense CO.sub.2 and a thickener soluble in the dense CO.sub.2. The thickener includes a copolymer that is the polymerized reaction product of monomers that include at least one alkenyl ether or dialkenyl ether monomer, at least one acrylate or methacrylate monomer, at least one structural monomer, and at least one allyl ester monomer. After injecting the dense CO.sub.2 composition into the high permeability zone, the method includes withdrawing hydrocarbons from the hydrocarbon bearing subterranean formation through the production well. The dense CO.sub.2 composition blocks pores in the high permeability zone to reduce or prevent flow of water from the high permeability zone into the production well.

Systems and methods for producing controlled vibrations within a borehole. In one example, the system includes a movement mechanism and a controller. The movement mechanism is configured to enable translational movement of a first surface relative to a second surface to allow the first surface to impact the second surface to produce a plurality of beats. The frequency and amplitude of the beats may be selectively controlled by suppressing or dampening the beats. The controller is configured to selectively control an amplitude or frequency of the beats to encode information therein, where the amplitude of a beat may be selectively controlled by dampening or suppressing the impact of the first surface and the second surface.

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.