An overview of logging technology in oil and gas fields
Li guan lan;
Geologging, which is usually referred to in the oil industry as mud logging, is a continuous monitoring system of various parameters during drilling of exploratory-assessment wells aimed for geological, gas logging, drilling, and overpressure studies. Inasmuch as it is a formation evaluation tool,monitoring of the various parameters must be carried out by geologists, who keep round-the-clock watch and plot data on various log sheets. Geologging data are equally useful when drilling development wells, as it helps in pinpointing the gas-oil and oil-water contacts with the help of gas chromatography as well as fluorescence studies. The use of gas chromatography, which is a part of geologging, is also helpful in determining the compositional characteristics of natural gases and in identifying the wet and dry gases. The other principal application of geologging is in carrying out overpressure studies during the course of drilling and to predict pore pressure well ahead, to avoid serious well hazards, which could result in the loss of time,personnel, material, and money unless timely action is taken. Selection of the type of geologging unit depends on the area. However, with the advance in computer technology, on-line geologging units for areas where the geology is complicated and not clearly understood have come into use and played a major role in formation evaluation during the course of drilling. Geologging, is, in fact, a foolproof formation evaluation tool for carrying out the qualitative determination of oil and gas occurring in the formation. However, the data obtained have to be supplemented by wireline logs when making vital decisions with regard to casing and testing policies and other details related to both exploratory and development wells.
【CateGory Index】： P618.13;P631.81