The invention discloses an experimental test method for subcritical propagation rate of rock fractures based on triaxial stress-strain curve, including: Step 1: preparing test sample core for experiment; Step 2: putting core into triaxial rock mechanics test system, applying constant radial confining pressure to core, and applying axial stress in the axial direction until the core is macroscopically damaged; recording experimental parameters of axial stress, strain and corresponding loading time of the core; Step 3: drawing stress-strain curve of the test core according to detection data points of axial stress and axial strain; Step 4: in the stress-strain curve of the test core, starting time and ending time of the subcritical propagation stage of fractures inside the core correspond to the initiation stress σci and damage stress σcd, respectively, and calculating subcritical propagation rate of the subcritical fracture propagation stage of the test core.

An apparatus for measuring mechanical properties of a downhole material, including first and second fixtures each of the fixtures containing a force application fixture to apply a stress to a specimen of the downhole material. A confining sleeve wraps around portions of the first and second fixtures to form a sealed specimen chamber defined by an inner surface of the confining sleeve and ends of the first and second fixtures nearest the specimen. Wall of a confining chamber contain the first and second fixtures, the confining sleeve and the specimen therein. The confining chamber holds a hydraulic fluid therein such that the hydraulic fluid can exert a confining pressure on the confining sleeve to maintain the seal of the specimen chamber and to maintain contact between the inner surface of the confining sleeve and the specimen when the stress is applied to the specimen. First channels pass though one or more of the walls of the confining chamber to add and remove the hydraulic fluid to and from the confining chamber. Second channels pass though one or more of the walls of the confining chamber and through one of the first and second fixtures to add and remove a pore space fluid to and from specimen chamber ports open to the specimen chamber to maintain a pore pressure at the specimen chamber ports that is equal to or less than the confining pressure while the stress is applied to the specimen. A system and method are also disclosed.

In one aspect, an apparatus includes a chamber configured to control one or more of humidity, pressure, or temperature and a jaw configured to flex a material system. The chamber includes an enclosure disposed within the chamber, the enclosure having an insulating material, and a motor or an actuator disposed within the enclosure. The chamber includes an inlet tube coupled with the enclosure at a first end and a first wall of the chamber at a second end. In one aspect, a method for determining material performance includes exposing a material system to a relative humidity of from 0% to 98% and flexing the material system at a first temperature in a chamber, the chamber comprising an enclosure disposed within the chamber and a motor disposed within the enclosure. The method includes operating the motor at a second temperature different from the first temperature during the flexing.

An apparatus for measuring a degree of cure and a specific volume of a packaging material is provided, including: an upper load module configured for driving the rotation of an upper ball screw via an upper servo motor such that a force plate coupled to the upper ball screw moves downward and is thus positioned; a lower load module having a lower ball screw operating and moving via a lower servo motor such that a load joint group connected to the lower ball screw generates a corresponding displacement; an upper film cavity module connected to the upper load module; and a lower film cavity module disposed on the lower load module. The displacement of the load joint group enables a push rod to move upward. A heating pipe keeps constant the temperature of a subject to be measured in a cavity of the lower film cavity module.

A clamping triaxial seepage and acoustic coupling rock tensile testing machine includes a sample and a scaffold-type tensile testing device. The scaffold-type tensile testing device has an upper chuck and a lower chuck. The upper chuck has an acoustic transmitting channel, one end of which communicating with the outside, and the other end of which having an acoustic transmitting probe. The lower chuck has an acoustic receiving channel, one end of which communicating with the outside, and the other end having acoustic receiving probe. An upper end face of the sample has with a seepage outflow hole while the upper chuck has a seepage outflow channel connected with the seepage outflow hole. A lower end face of the sample has a seepage inflow hole while the lower chuck has a seepage entry channel is connected with the seepage inflow hole.

An apparatus and method for testing a core rock sample for reservoir souring. The apparatus includes first and second pumps, and a piston cell associated with each of the first and second pumps. Each piston cell has a first portion and a second portion divided by a movable piston such that the second portion is fluidly sealed from the first portion. Each piston cell is configured to receive fluid pumped by its respective pump into the first portion thereof. A core holder is sized to receive and maintain a core rock sample at a desired pressure and temperature. The second portions of each of the piston cells are fluidly connected to the core holder.

Disclosed is an exemplary test apparatus having an autoclave head, a fretting mechanism connected on a first end to a first side of the autoclave head, a load train operably connected with a first end of the fretting mechanism, an autoclave adapter connected on a first side to a second side of the autoclave head, and a force balance assembly connected to a second side of the autoclave head and configured to equalize a pressure acting on the load train. Certain exemplary embodiments include an upper plate, a plurality of upper tie rods connected to a first side of the upper plate and a second side of the autoclave adapter, a lower plate, a plurality of lower tie rods connected to the first side of the autoclave head and a first side of the lower plate, and a pressure vessel sealingly connected to the first side of the autoclave head.

The present invention improves the precision in observing cracks in rocks during a hydraulic fracturing test, improving a scientific understanding of the regular pattern of development cracks in of hydraulically fractured rocks. The technical solution includes: hydraulically fracturing the rock with aqueous solutions containing an interventional contrast-enhanced agent, forming hydraulically fractured cracks, wherein the difference in a mass attenuation coefficient / of x-rays between the cracks and the rock is improved by the interventional contrast-enhanced agent in the cracks, moreover, the difference in mass energy absorption coefficient .sub.en/ of x-rays between the cracks and the rock is improved, then the linear attenuation coefficient of the reception of the detector is changed, improving the imaging resolution for hydraulically fractured cracks in the rock.

A method for enhanced interventional imaging for cracks, improving the precision in observing cracks in rock hydraulic fracturing test, benefiting for scientifically understanding regular pattern of development of hydraulically fractured cracks in rocks. The technical solution comprises: hydraulically fracturing the rock with aqueous solutions containing nanoscale interventional contrast-enhanced agent which has a high atomic number; forming hydraulically fractured cracks, wherein the difference in mass attenuation coefficient / of x-ray between the cracks and the rock is improved by the interventional contrast-enhanced agent in the cracks, moreover, the difference in mass energy absorption coefficient .sub.en/ of x-ray between the cracks and the rock is improved, then the linear attenuation coefficient of the reception of detector is changed, improving the imaging resolution for hydraulically fractured cracks in the rock.

An apparatus for measuring a degree of cure and a specific volume of a packaging material is provided, including: an upper load module configured for driving the rotation of an upper ball screw via an upper servo motor such that a force plate coupled to the upper ball screw moves downward and is thus positioned; a lower load module having a lower ball screw operating and moving via a lower servo motor such that a load joint group connected to the lower ball screw generates a corresponding displacement; an upper film cavity module connected to the upper load module; and a lower film cavity module disposed on the lower load module. The displacement of the load joint group enables a push rod to move upward. A heating pipe keeps constant the temperature of a subject to be measured in a cavity of the lower film cavity module.