Abstract: A hydrocarbon recovery method for recovering a production fluid containing hydrocarbons from a production well provided in the ground in which Type 1 microorganisms that produce a biological membrane (biofilm) and Type 2 microorganisms that produce carbon dioxide for promoting deposition of calcium carbonate exist, the hydrocarbon recovery method includes injecting, into the production well, a culture medium for increasing the Type 1 microorganisms; injecting, into the production well, a composition used for the Type 2 microorganisms to produce carbon dioxide, decompressing an inside of the production well after the culture medium and the composition are injected, and recovering the hydrocarbons in a state where the inside of the production well is decompressed.

Abstract: A hydrocarbon recovery method for recovering a production fluid containing hydrocarbons from a production well provided in the seabed in which microorganisms that produce carbon dioxide or sulfate ions for promoting a deposition of calcium carbonate exist, the method includes: an injecting process of injecting, into the production well, a composition used for producing carbon dioxide or sulfate ions by the microorganisms; a decompressing process of decompressing an inside of the production well after the composition is injected; and a recovering process of recovering the hydrocarbons in a state in which the inside of the production well is decompressed.

Abstract: A hydrocarbon recovery method for recovering a production fluid containing hydrocarbons from a production well provided in the seabed in which microorganisms that produce carbon dioxide or sulfate ions for promoting a deposition of calcium carbonate exist, the method includes: an injecting process of injecting, into the production well, a composition used for producing carbon dioxide or sulfate ions by the microorganisms; a decompressing process of decompressing an inside of the production well after the composition is injected; and a recovering process of recovering the hydrocarbons in a state in which the inside of the production well is decompressed.

Abstract: Disclosed is a heat-sensitive recording material comprising a support and a heat-sensitive recording layer formed on the support and containing a leuco dye, a developer and a binder, wherein the heat-sensitive recording material uses as the developer at least two hydroxy-diphenylsulfone compounds such as 4-hydroxy-4?-isopropoxy-diphenylsulfone, 2,4?-dihydroxy-diphenylsulfone and the like, and uses as the leuco dye a black-color-forming leuco dye such as 3-di(n-butyl)amino-6-methyl-7-anilinofluoran or the like and 0.5 to 3.5 wt. %, relative to the black-color-forming leuco dye, of a red-color-forming leuco dye such as 3-diethylamino-7-chlorofluoran or the like.

Abstract: Disclosed is a heat-sensitive recording material comprising a support and a heat-sensitive recording layer formed on the support and containing a leuco dye, a developer and a binder, wherein the heat-sensitive recording material uses as the developer at least two hydroxy-diphenylsulfone compounds such as 4-hydroxy-4′-isopropoxy-diphenylsulfone, 2,4′-dihydroxy-diphenylsulfone and the like, and uses as the leuco dye a black-color-forming leuco dye such as 3-di(n-butyl)amino-6-methyl-7-anilinofluoran or the like and 0.5 to 3.5 wt. %, relative to the black-color-forming leuco dye, of a red-color-forming leuco dye such as 3-diethylamino-7-chlorofluoran or the like.