Abstract: An apparatus and methods for sidewall percussion coring service are disclosed. In some embodiments, the side-wall percussion coring tool includes a voltage activated igniter, explosive material, and a core barrel in communication with the explosive material, wherein activation of the igniter causes detonation of the explosive material to propel the core barrel from tool. Some method embodiments for performing sidewall percussion coring service using the disclosed sidewall percussion coring tool include positioning the tool within a wellbore, activating the voltage activated igniter housed within the tool, detonating the explosive material within the tool with the voltage activated igniter, propelling a core barrel from the tool into the surrounding formation by detonation of the explosive material, retrieving the core barrel from the formation, and removing the tool from the wellbore.

Abstract: An apparatus and methods for sidewall percussion coring service are disclosed. In some embodiments, the side-wall percussion coring tool includes a voltage activated igniter, explosive material, and a core barrel in communication with the explosive material, wherein activation of the igniter causes detonation of the explosive material to propel the core barrel from tool. Some method embodiments for performing sidewall percussion coring service using the disclosed sidewall percussion coring tool include positioning the tool within a wellbore, activating the voltage activated igniter housed within the tool, detonating the explosive material within the tool with the voltage activated igniter, propelling a core barrel from the tool into the surrounding formation by detonation of the explosive material, retrieving the core barrel from the formation, and removing the tool from the wellbore.

Abstract: A water soluble, acid precipitable polymeric degraded lignin (APPL), having a molecular weight of at least 12,000 daltons, and comprising, by percentage of total weight, at least three times the number of phenolic hydroxyl groups and carboxylic acid groups present in native lignin. The APPL may be modified by chemical oxidation and reduction to increase its phenolic hydroxyl content and reduce the number of its antioxidant inhibitory side chains, thereby improving antioxidant properties.