borehole logging measurement
91Formation evaluation gamma ray — In the field of formation evaluation, gamma ray log records natural radioactivity emission of formation. Measurement of natural emission of gamma rays in oil and gas wells are particularly helpful because shales and sandstones typically have… …
92Drilling rig — For a detailed diagram of a Petroleum drilling rig, see List of components of oil drilling rigs. Drilling rig preparing rock blasting …
93Formation evaluation neutron porosity — In the field of formation evaluation, porosity is one of the key measurements to quantify an oil and gas reserves. Neutron porosity measurement employs neutron source to measure hydrogen index in a reservoir, which is directly related to porosity …
94Spontaneous potential — In the field of formation evaluation, spontaneous potential (SP) is a naturally occurring electric potential difference in the Earth, measured by an electrode in a borehole relative to a fixed reference electrode on the surface. SP was first… …
95Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
96Driller's depth — The original depth recorded while drilling an oil or gas well is known as the Driller s Depth. Contents 1 The Problem 1.1 Measurement of Driller s Depth 1.2 Measuring drill string length 1.2.1 …
97Gas porosity — Determining the true porosity of a gas filled formation has always been a problem. While gas is a hydrocarbon, similar to oil, the physical properties of the fluids are very different, making it very hard to correctly quantify the total amount of …
98Deviation survey — A Deviation survey[1], more generally known in the oil industry as simply a survey , is the measurement of a borehole s departure from the vertical, measured in degrees (°). When a well plan dictates the drilling of a straight borehole, surveys… …
99tunnels and underground excavations — ▪ engineering Introduction Great tunnels of the world Great tunnels of the worldhorizontal underground passageway produced by excavation or occasionally by nature s action in dissolving a soluble rock, such as limestone. A vertical opening …
100Geotechnical investigation — Geotechnical investigations are performed by geotechnical engineers or engineering geologists to obtain information on the physical properties of soil and rock around a site to design earthworks and foundations for proposed structures and for… …
