摘要:
The invention relates to a method for determining the geology at a geographical location while drilling, which method comprises the steps of: - performing sonic drilling with a drill pipe, a sonic drilling head, wherein the drill pipe is coupled to the sonic drilling head and wherein the sonic drilling head has vibration means for vibrating the drill pipe; - measuring the vibrations of the drill pipe during drilling; - converting the measured vibrations from the time domain to the frequency domain by applying a Fourier transformation; and - determining the soil composition at the momentary drill depth by comparing the frequency pattern from the Fourier transformation with predefined frequency patterns for different soil compositions.
摘要:
The present invention relates to a method of seismic exploration utilizing vibrationally generated, elliptically polarized shear waves (62) in an earth medium (38) for subsequent detection of one or more dimensions of orthogonal particle motion. A preferred form of shear wave source (40) is of a type which couples a continually rotating longitudinal force into an earth medium thereby to propagate an elliptically polarized shear wave (62) for refraction, reflection or subsurface detection, for various forms of exploration.
摘要:
Method for seismic prospecting using counter-rotating (207-208) eccentric-mass (201, 202) vibrator (CREMV) technology adapted as vibrator sources for seismic prospecting to produce controlled sweeps, as in the manner used in modern seismic prospecting, but with large forces at low frequencies, e.g. forces > 275 kN at frequencies between 1 and 5 Hz. This is achieved by adapting the CREMV to enable rotational frequency and the eccentricity (205, 206) of the masses relative to their rotation axes (203-204) to be varied independently and simultaneously, and by designing the CREMV such that the radius of rotation of the center of mass of each rotating mass is on the order of 50 cm or more. The low frequency data obtained from such a seismic source enables improved detection and resolution of subsurface structures and better determination of subsurface properties
摘要:
An orbital vibrator (12) comprises a rotatable shaft (14) with a crank (28) attached thereto, a bearing (31) mounted on said crank, a reaction mass (30) mounted on said crank by means of said bearing and, by virtue of said mounting, orbitally oscillating about said crank in response to the rotation of said shaft in order to induce avibratory motion.
摘要:
The present invention relates to a method of seismic exploration utilizing vibrationally generated, elliptically polarized shear waves (62) in an earth medium (38) for subsequent detection of one or more dimensions of orthogonal particle motion. A preferred form of shear wave source (40) is of a type which couples a continually rotating longitudinal force into an earth medium thereby to propagate an elliptically polarized shear wave (62) for refraction, reflection or subsurface detection, for various forms of exploration.
摘要:
Apparatus for simultaneously generating elliptically polarized seismic shear waves and compression waves downhole for coupling energy through the fluid into a borehole wall (12). The apparatus includes an elongate frame (26) for support in the borehole and the frame includes a drive means (36,42) energizable to impart an orbital motion to at least a portion of the frame thereby to generate an orbital shear wave.