Abstract: A monopole acoustic logging while drilling instrument used together with a bottom hole assembly and a method for measuring a shear wave velocity of slow formations, wherein the bottom hole assembly includes a drill collar and a drill bit, wherein the monopole acoustic logging while drilling instrument is installed on the drill collar. The monopole acoustic logging while drilling instrument comprises: an acoustic receiver array installed on the drill collar; a monopole acoustic source arranged at the drill collar, wherein the monopole acoustic source is configured to emit acoustic waves with a frequency in a preset frequency range, and the ratio of the outer diameter D1 of the drill collar to the outer diameter D2 of the drill bit is d, and 0.75<d<1.

Abstract: A monopole acoustic logging while drilling instrument used together with a bottom hole assembly and a method for measuring a shear wave velocity of slow formations, wherein the bottom hole assembly includes a drill collar and a drill bit, wherein the monopole acoustic logging while drilling instrument is installed on the drill collar. The monopole acoustic logging while drilling instrument comprises: an acoustic receiver array installed on the drill collar; a monopole acoustic source arranged at the drill collar, wherein the monopole acoustic source is configured to emit acoustic waves with a frequency in a preset frequency range, and the ratio of the outer diameter D1 of the drill collar to the outer diameter D2 of the drill bit is d, and 0.75<d<1.

Abstract: The present application provides a seismic travel time tomographic inversion method based on two-point ray tracing comprising: collecting seismic data including direct wave travel time and reflected wave travel time; establishing an initial one-dimensional continuously layered model having continuously a varying intraformational velocity; representing a ray parameter p by a variable q, representing a source-receiver distance X by a function X=f(q) of the variable q, solving the function X=f(q) using a Newton iteration method; calculating a theoretical direct wave travel time and reflected wave travel time according to the ray parameter p; comparing the calculated theoretical arrival time with actual arrival time, using an optimal algorithm to adjust velocity parameters of the initial one-dimensional continuously layered model, until a difference between the theoretical direct wave travel time and reflected wave travel time and the actual direct wave travel time and reflected wave travel time complies with a p

Abstract: A method, device, terminal and computer readable storage medium for determining a cross-sectional shape of a borehole involves obtaining a plurality of logging data items as measured at a same depth of a well via a multi-arm caliper. The logging data items include pad coordinates which use a center of the multi-arm caliper as a reference point. Coordinates of a borehole center and a borehole radius at the depth of the well are obtained by using a least squares objective function with a constraint condition and according to the pad coordinates. The constraint condition is that a distance from a pad of a caliper tool to the borehole center is larger than or equal to the borehole radius. The pad positions are located outside a circle or on the circle obtained by fitting according to the least squares objective function, such that a real borehole cross-sectional shape is obtained.

Abstract: A system and method for determining shear wave anisotropy in a vertically transversely isotropic formation is disclosed. The method includes generating a broad band Stoneley wave and a broad band dipole flexural wave. The broad band Stoneley wave and a broad band dipole flexural wave may be generated at a logging tool located within a wellbore. The method also includes receiving at the logging tool first data corresponding to the broad band Stoneley wave and second data corresponding to the broad band dipole flexural wave. The method also includes determining a vertical shear wave constant, c66, by at least applying an inversion algorithm to the first data and the second data.