Electromagnetic wave resistivity methods in Measurement-While-Drilling and Logging-While-Drilling applications, or simply MWD/LWD, are now approaching their fourth decade of practice. Th ey are instrumental in anisotropy determination, dip angle analysis, bed boundary detection, fl uid identifi cation, and so on, and are important to economic analysis, stimulation planning, geosteering, unconventional resources and numerous exploration challenges.

The physical theories behind Measurement-While-Drilling design should be rich in scientific challenges, engineering principles and mathematical elegance. To develop the next generation of high-data-rate tools, these must be understood and applied unfailingly without compromise. But one does not simply peruse the latest petroleum books, state-of-the-art reviews, or the most recent patents to understand their teachings. Most descriptions are just wrong. The science itself does not exist.

Our modern world needs more and more resources provided by our planet Earth: foods, water, raw materials, ores and energy, either natural (sun, wind, hydraulic, tidal, geothermal, nuclear) or fossil (coal, petroleum, gas). An on-going effort in research and exploration is therefore necessary to discover, exploit and develop them. And, in this effort, it is better to rely on information coming from fundamental research, development of technology and geological studies, than on hazard and luck! Geological studies more and more rely on different sources of information coming from use of new analytical methods and physical sensors such as well logging tools. <...>

Once the prospect generation is made based on seismic and geological surveys, location for drilling is released based on the most probable structure in the hydrocarbon point of view. The most probable structure is based on the structure identified with

This example shows the "multi-track" recording of the interval between 11 396 and 11441 feet of a well drilled in 1972 in a dominantly shaly deltaic series with thin sandy and dolomitic crossbedding.

The applications of nuclear magnetic resonance (NMR) to petroleum expb ration and production have become more and more important in recent years. The development of the NMR logging technology and the NMR applications to core analysis and formation evaluation have been very rapid and extensive. Part of this book was a collection of many lecture notes written over the years for Chevron in-house training purposes. As we started writing, the scope of the book gradually broadened.

Our modern society has a constant need for raw materials and energy. An on-going effort in exploration and research is necessary, therefore, to discover and develop them. And, in this effort, it is better to appeal to geology than to rely on chance. Geology is by definition "the study of the planet Earth. It is concerned with the origin of the planet, the material and morphology of the Earth, and its history and the processes that acted (and act) upon it to affect its historic and present forms" (Glossary of Geology, 1980).

Метод спонтанной поляризации или метод потенциалов собственной поляризации (ПС) является одним из старейших и основных геофизических методов каротажа, применяемый для изучения геологического строения пород, пройденных геологоразведочными скважинами. Широкое производственное применение метода началось еще в первой трети прошлого века после экспериментов, проведенных братьями Шлюмберже и советским ученым Итенбергом С.С. на нефтяных месторождениях Чечни на Северном Кавказе.

The spontaneous potential well-logging is one of the most common and useful welllogging techniques in petroleum exploitation. Since the earth layer can be regarded as a piecewise uniform medium, and due to electrochemical and other factors, there exists a jump of potential (spontaneous potential difference) on each interface of different layers.

Geology is the science that deals with the history and structure of the earth and its life forms, especially as recorded in the rock record. A basic understanding of its concepts and processes is essential in the petroleum industry, for it is used to predict where oil accumulations might occur.