Abstract: The method for equal channel angular extrusion increases yield strength and ultimate tensile strength of a dissolvable aluminum alloy. A billet of a dissolvable aluminum alloy is wrapped with a sheet cover so as to form a wrapped billet. The wrapped billet is extruded through an equal channel angular extrusion die with an extrusion angle ranging 90-135 degrees so as to form an extruded billet. The step of extruding is at a temperature ranging 150-250 degrees C., an extrusion rate ranging 0.003-0.010 inches per second, and a back pressure ranging 200-10000 psi. The dissolvable aluminum alloy of the extruded billet has a yield strength and ultimate tensile strength 50% greater than the initial yield strength and initial ultimate tensile strength.

Abstract: A dissolvable aluminum alloy can be used for components of a downhole tool in hydraulic fracturing operations with low salinity fluid at low temperatures, including fresh water. The dissolvable aluminum alloy can be dissolved completely and controlled at a dissolving rate compatible with hydraulic fracturing operations. The alloy comprises aluminum having grain boundaries, magnesium at 8.25-12% by weight, gallium at 2.5-4% by weight, and indium at 2-4% by weight. At least portions of magnesium, gallium, and indium are located in the grain boundaries. There are secondary phase particles, including Al—Mg Beta, Mg2Si, Mg and Al—Ga Gamma phases at the grain boundaries.

Abstract: The invention provides a method and device for measuring the elasticity of hardened cement for cementing of oil-gas wells. The measurement method comprises: determining the loading and unloading rates of the hardened cement; determining the maximum loading on the hardened cement; determining the experimental temperature and the experimental pressure of the hardened cement; establishing a stress-strain curve for the hardened cement; and describing the elasticity of the hardened cement with the degree of strain recovery of the hardened cement in different cycles, and describing the mechanic integrity of the hardened cement with the degree of damage to the hardened cement in different cycles. The invention further provides a device for measuring the elasticity of hardened cement for cementing of oil-gas wells.

Abstract: The invention provides a method and device for measuring the elasticity of hardened cement for cementing of oil-gas wells. The measurement method comprises: determining the loading and unloading rates of the hardened cement; determining the maximum loading on the hardened cement; determining the experimental temperature and the experimental pressure of the hardened cement; establishing a stress-strain curve for the hardened cement; and describing the elasticity of the hardened cement with the degree of strain recovery of the hardened cement in different cycles, and describing the mechanic integrity of the hardened cement with the degree of damage to the hardened cement in different cycles. The invention further provides a device for measuring the elasticity of hardened cement for cementing of oil-gas wells.