| 摘要 |
<p>The invention relates to borehole treatment agent containing an aqueous phase and a non-aqueous oil phase, emulsifiers and, optionally, other usual additives, such as loading agents, fluid-loss additives, viscosity regulating additives, wetting agents, salts, bio targets, corrosion inhibitors, and/or an alkali reserve. The non-aqueous phase is completely or partially selected from the group which contains a) paraffin having 5 - 22 C-atoms and /or b) internal olefins having 12 - 30 C-atoms per molecule respectively in a mixture with c) carboxylic acid esters of general formula R-C00-R' wherein R represents a linear or branched, saturated or unsaturated alkyl radical having 15 - 25 C-atoms and R' represents a saturated, linear or branched alkyl radical having 3 - 22 C atoms. The invention is characterised in that the quotient of the toxicity of internal olefins of chain length C16/C18 (Standard 10) and the toxicity of the components of the non aqueous phase, measured according to the Leptocheirus plumulosus acute, static 96-hour/10 day sediment toxicity test (according to ASTM E 1367 - 92 & EPA/60018-94/025, section 11), is less than 1.</p> |
