Abstract: In chromatography, the weight percent of higher boiling hydrocarbons is estimated by comparing areas under the certain segments of chromatograms. This procedure is subject to both human and equipment errors. A supplemental procedure for measuring the percent of higher boiling point hydrocarbons is disclosed. This procedure is specially related to chromatography and uses gradual heating and inert gas vaporization of the lower boiling point hydrocarbons in the sample material. In the procedure, a sample of the same hydrocarbon tested in the chromatograph is weighed and is heated to the same temperature as used in the chromatograph while flowing inert gas, e.g. helium, past the sample. After reaching this temperature, gas flow is continued for at least eight minutes. The residual sample is weighed and the difference used to determine and check the chromatograph estimation. The procedure may be checked with a calibrated sample of hydrocarbons boiling at and below the final maximum test temperature.

Abstract: Method and apparatus for electrical logging in a mud-filled borehole by sensing redox potential and other formation characteristics. An elongated, tubular probe body contains reference and potential measuring electrodes which extend longitudinally thereof and are adapted to make external contact with the borehole fluid at the streamlined surface of the probe nose. The metal reference electrode member is immersed in an electrolyte-filled compartment separated from the external borehole fluid by a pressure-compensating diaphragm in the probe side wall, a fluid bridge with the mud of the borehole being established through a permeable ceramic wick. Probe design insures adequate mud flow past the electrodes in a nonturbulent state as the probe is lowered, thus eliminating clogging and providing good electrical contact. Alternate means are provided for maintaining a positive leak pressure regardless of borehole conditions.