A penetration-type monitor includes a casing pipe and sensor penetration scissors, the sensor penetration scissors are arranged in a shear shape, and a first blade and a second blade rotate close to each other or away from each other in the vertical direction so as to define an initial position and a monitoring position of the sensor penetration scissors; when the sensor penetration scissors are located at the initial position, ends of pressed portions of the first blade and the second blade are arranged at an interval one above the other, when the sensor penetration scissors are located at the monitoring position, the pressed portions move close to each other, and shearing portions penetrate out of a mounting hole to shear a sliding mass; and a monitor arrangement system drives the sensor penetration scissors to move from the initial position to the monitoring position.

An in-situ stress measurement method is provided. The method includes measuring a length of a maximum diameter at which an amount of distortion relative to a diameter of a standard circle of a measurement cross section of a boring core is largest and a length of a minimum diameter at which the amount of distortion relative to the diameter of the standard circle is smallest based on a shape of the measurement cross section of the boring core; measuring a length of a diameter in a vertical direction and a length of a diameter in a horizontal direction of the measurement cross section of a side-wall core acquired by hollowing ground in a well in an excavation direction thereof, based on a shape of the measurement cross section of the side-wall core; and calculating a maximum horizontal stress and a minimum horizontal stress by first and second equations.

This disclosure relates to a method and a system for sequestering carbon-containing materials in underground wells. An example method includes: obtaining a material comprising a carbon-containing liquid; optionally testing the material for compatibility with an underground well; optionally adjusting a property of the material to improve the compatibility; and providing the material for injection into the underground well.

This disclosure relates to a method and a system for sequestering carbon-containing materials in underground wells. An example method includes: obtaining a material comprising a carbon-containing liquid; optionally testing the material for compatibility with an underground well; optionally adjusting a property of the material to improve the compatibility; and providing the material for injection into the underground well.

A method of evaluating gel stability of a gel for treating a subterranean formation includes placing a composite core plug into a core holder of a coreflood testing device where the composite core plug comprises first, second, and third core plugs, alternating injection of polymer solution into first and second injection areas, and monitoring a pressure drop across the composite core plug as a function of time. The method further includes identifying a gelation of a gelent solution in the third core plug, where the gelation is indicated by an increase in the pressure drop across the composite core plug, after the increase in the pressure drop indicative of the gelation point, continuing alternating injections of the polymer solution into the first and second injection areas, and identifying a reduction in the pressure drop across the composite core plug indicative of deterioration of the gel.

A method of evaluating gel stability of a gel for treating a subterranean formation includes placing a composite core plug into a core holder of a coreflood testing device where the composite core plug comprises first, second, and third core plugs, alternating injection of polymer solution into first and second injection areas, and monitoring a pressure drop across the composite core plug as a function of time. The method further includes identifying a gelation of a gelent solution in the third core plug, where the gelation is indicated by an increase in the pressure drop across the composite core plug, after the increase in the pressure drop indicative of the gelation point, continuing alternating injections of the polymer solution into the first and second injection areas, and identifying a reduction in the pressure drop across the composite core plug indicative of deterioration of the gel.

A performance evaluation device and a design method of a cement for well cementing in a penetrated hydrate layer are provided. The performance evaluation device includes an equivalent wellbore, an inner circulation system, an outer circulation system, a thermal insulation cover, a bracket, a temperature sensing system, and a cement mold. The device can simulate a true downhole situation, conduct an evaluation experiment on the heat insulation performance of a cementing cement, and conduct experiments at different temperatures with automatic temperature control. The design method is to use a low-hydration, early-strength, and heat-insulating cement slurry system during the well cementing in a penetrated hydrate layer, where the low-hydration and early-strength characteristics ensure the effective sealing of a hydrate layer during a cementing process, and the heat insulation characteristic results in low heat conductivity and thus can ensure the stability of a hydrate layer during a production operation.

A performance evaluation device and a design method of a cement for well cementing in a penetrated hydrate layer are provided. The performance evaluation device includes an equivalent wellbore, an inner circulation system, an outer circulation system, a thermal insulation cover, a bracket, a temperature sensing system, and a cement mold. The device can simulate a true downhole situation, conduct an evaluation experiment on the heat insulation performance of a cementing cement, and conduct experiments at different temperatures with automatic temperature control. The design method is to use a low-hydration, early-strength, and heat-insulating cement slurry system during the well cementing in a penetrated hydrate layer, where the low-hydration and early-strength characteristics ensure the effective sealing of a hydrate layer during a cementing process, and the heat insulation characteristic results in low heat conductivity and thus can ensure the stability of a hydrate layer during a production operation.

Methods and systems for determining pore-volume of a fracture in a core plug. The method includes developing a grid block model constrained by fracture porosity estimated from a mechanical laboratory test, aperture calculation, and discrete fracture model validation. The method further includes determining the natural fracture porosity and pore volume from the equivalent medium for natural fractures, determining oil or gas reserves by calculating the fracture pore volume, and determining fracture porosity measurement from a test to calibrate 3D fracture models. The method also includes determining fracture porosity from a mechanical test, analyzing borehole image logs, developing a geomechanical model and fracture drivers, performing fracture model predictions, validating and calibrating the model, and determining fracture pore-volume of the core plug.

Methods and systems for determining pore-volume of a fracture in a core plug. The method includes developing a grid block model constrained by fracture porosity estimated from a mechanical laboratory test, aperture calculation, and discrete fracture model validation. The method further includes determining the natural fracture porosity and pore volume from the equivalent medium for natural fractures, determining oil or gas reserves by calculating the fracture pore volume, and determining fracture porosity measurement from a test to calibrate 3D fracture models. The method also includes determining fracture porosity from a mechanical test, analyzing borehole image logs, developing a geomechanical model and fracture drivers, performing fracture model predictions, validating and calibrating the model, and determining fracture pore-volume of the core plug.