increased diameter of drilling bit
1Drilling rig — For a detailed diagram of a Petroleum drilling rig, see List of components of oil drilling rigs. Drilling rig preparing rock blasting …
2Drill bit — For the fictional character, see Drill Bit (Transformers). For the cancelled skyscraper nicknamed Drill bit, see Chicago Spire. For the types used in drilling wells, see Well drilling. From top to bottom: Spade, lip and spur (brad point), masonry …
3Directional drilling — A horizontal directional drill in operation Directional drilling (or slant drilling) is the practice of drilling non vertical wells. It can be broken down into three main groups: Oilfield Directional Drilling, Utility Installation Directional… …
4Quecreek Mine Rescue — The Quecreek Mine Rescue took place when nine miners were trapped underground for over 78 hours, July 24 ndash;28, 2002. All nine miners were rescued.Accident and rescueOn July 24, 2002, coal miners at the Quecreek Mine in Lincoln Township,… …
5Evolutionary history of plants — Plants have evolved through increasing levels of complexity, from the earliest algal mats, through bryophytes, lycopods, ferns and gymnosperms to the complex angiosperms of today. While the simple plants continue to thrive, especially in the… …
6List of Chinese inventions — A bronze Chinese crossbow mechanism with a buttplate (the wooden components have …
7mining — /muy ning/, n. 1. the act, process, or industry of extracting ores, coal, etc., from mines. 2. the laying of explosive mines. [1250 1300; ME: undermining (walls in an attack); see MINE2, ING1] * * * I Excavation of materials from the Earth s… …
8tunnels 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 …
9Water well — Village pump redirects here. For information on Wikipedia project related discussions see Wikipedia:Village pump. Water well at the Wald monastery in Germany. A water well is an excavation or structure created in the ground by digging, driving,… …
10Business and Industry Review — ▪ 1999 Introduction Overview Annual Average Rates of Growth of Manufacturing Output, 1980 97, Table Pattern of Output, 1994 97, Table Index Numbers of Production, Employment, and Productivity in Manufacturing Industries, Table (For Annual… …
