| 摘要 |
1,093,663. Drilling muds. CHEVRON RESEARCH CO. June 22, 1966 [June 24, 1965], No. 27895/66. Heading E1F. The nitrate ion originally added to a drilling mud is compared with the amount of ion which filters into a liquid well sample and the ratio is used as a measure of the invasion by the mud filtering into the liquid sample. Methods of measuring nitrate ions are described. |
