Abstract: A method is given of fracturing a subterranean formation including the step of a) pumping at least one device actively transmitting data that provide information on the device position, and further comprising the step of assessing the fracture geometry based on the positions of said at least one device, or b) pumping metallic elements, preferably as proppant agents, and further locating the position of said metallic elements with a tool selected from the group consisting of magnetometers, resistivity tools, electromagnetic devices and ultra-long arrays of electrodes, and further comprising the step of assessing the fracture geometry based on the positions of said metallic elements. The method allows monitoring of the fracture geometry and proppant placement.

Abstract: A method and apparatus for producing gas from a hydrate formation includes the use of at least one wellbore which penetrates the hydrate formation and further extends into an aquifer below the hydrate formation. The aquifer provides relatively warm water which may be produced up and into the hydrate formation thereby causing the release of gas from the hydrate. Suitable flow control and monitoring equipment may be included to control the flow of water produced from the aquifer and gas produced from the hydrate formation.

Abstract: A method is given of fracturing a subterranean formation including the step of a) pumping at least one device actively transmitting data that provide information on the device position, and further comprising the step of assessing the fracture geometry based on the positions of said at least one device, or b) pumping metallic elements, preferably as proppant agents, and further locating the position of said metallic elements with a tool selected from the group consisting of magnetometers, resistivity tools, electromagnetic devices and ultra-long arrays of electrodes, and further comprising the step of assessing the fracture geometry based on the positions of said metallic elements. The method allows monitoring of the fracture geometry and proppant placement.

Abstract: The present invention relates to methods of fracturing a subterranean formation including the step of pumping at least one device actively transmitting data that provide information on the device position, and further comprising the step of assessing the fracture geometry based on the positions of said at least one device or pumping metallic elements, preferably as proppant agents, and further locating the position of said metallic elements with a tool selected from the group consisting of magnetometers, resistivity tools, electromagnetic devices and ultra-long arrays of electrodes. The invention allows monitoring of the fracture geometry and proppant placement.

Abstract: A template for locating the proper placement of junction boxes and for marking a section of wall to be cut out to accommodate a junction box. The template comprises a first straight portion of designated length having a first end which is free and a second end defining an aperture which is about or slightly larger than the dimension of a junction box.

Abstract: The invention is related to a method of determininng the instantaneous rotation speed of a drill string or a drill bit in a borehole or the lateral shocks applied to the string or bit. The centripetal acceleration of the drill string is measured at at least two opposite ends of a drill string diameter so as to obtain two centripetal acceleration signals ac1 and ac2; the signals ac1 and ac2 are combined and the instantaneous rotation speed or the lateral shocks are derived from said combined signal. The accelerometers must be of the type delivering a signal with a DC component. An important application of the invention is to transform drill string rotation speed dependent data acquired versus time with a constant sampling time increment T.sub.c separating successive data, into compensated data which would be obtained for a substantially constant drill string rotation speed S.sub.c. The compensated data are obtained either by adjusting the constant sampling time interval T.sub.

Abstract: A method is provided for determining the state of wear of a multicone drill bit. Vibrations generated by the working drill bit are detected and converted into a time oscillatory signal from which a frequency spectrum is derived. The periodicity of the frequency spectrum is extracted. The rate of rotation of at least one cone is determined from the periodicity and the state of wear of the drill bit is derived from the rate of cone rotation. The oscillatory signal represents the variation in amplitude of the vertical or torsional force applied to the drill bit. To extract periodicity, a set of harmonics in the frequency spectrum is given prominence by computing the cepstrum of the frequency spectrum or by obtaining an harmonic-enhanced spectrum. The fundamental frequency in the set of harmonics is determined and the rate of cone rotation is derived from the fundamental frequency.