Abstract: Disclosed herein are various embodiments of a technique to monitor hydro-fracturing in oil and gas wells by use of active seismic sources and arrays of monitoring sensors. The invention utilizes combinations of seismic sources such as vertical vibrators in anti-phase pairs. The invention utilizes combinations of multi-component rotational seismic sensors, and/or multi-component linear sensors, and/or pressure sensors. Sensors are jointly deployed in arrays on the surface and/or in shallow monitoring wells to avoid the complicating effects of the free surface of the earth. The emplacement of sensors on the surface or in the shallow monitoring wells may be permanent. Fractures are monitored by combinations of physical effects such as propagation time delays, shear reflections, birefringent shear wave splitting, and amplitude variations. The method has a wide range of application in oil and gas exploration and production.

Abstract: A method for determining an optimum spacing of seismic energy sources based on mutual admittance includes deploying a plurality of seismic energy sources along a source line, separated by a selected spacing. Seismic receivers are deployed along a receiver line orthogonal to the source line. Seismic energy is simultaneously transmitted from each of the plurality of seismic energy sources while recording signals from the seismic receivers. The transmitting and recording of signals is repeated for a plurality of different spacings between the energy sources. Seismic energy in the recorded signals is determined in separate time windows selected to represent reflected body wave signal, and source generated ground roll noise, respectively. A signal-to-noise ratio with respect to the spacing of the seismic energy sources is calculated and the optimum spacing between energy sources is selected based on the signal-to-noise ratio.

Abstract: The present invention provides a technique to separate compressional seismic waves from shear seismic waves and to determine their direction of propagation to enhance the seismic monitoring oil and gas reservoirs and the seismic monitoring of hydrofracturing in oil and gas wells. The invention utilizes various combinations of multi-component linear seismic sensors, multi-component rotational seismic sensors, and pressure sensors. Sensors are jointly deployed in arrays of shallow monitoring wells to avoid the complicating effects of the free surface of the earth. The emplacement of sensors in the shallow monitoring wells may be permanent. The method has a wide range of application in oil and gas exploration and production. This abstract is not intended to be used to interpret or limit the claims of this invention.

Abstract: The present invention provides a method and apparatus for enhanced monitoring of induced seismicity and industrial vibration to comprehensively measure all aspects of potentially damaging motion. The invention utilizes various combinations of multi-component low frequency linear seismic sensors and multi-component rotational seismic sensors. Sensors are jointly deployed in arrays on the free surface of the earth, and/or in arrays of shallow monitoring holes, which may be intended to be permanent deployments. The method has a wide range of risk/damage monitoring applications for industrial activity, and in oil and gas exploration and production for seismic surveys, hydraulic fracturing, and waste injection wells. This abstract is not intended to be used to interpret or limit the claims of this invention.

Abstract: Disclosed herein are various embodiments of a method and apparatus to enhance spatial sampling in all nominally horizontal directions for Dual-Sensor seismic data at the bottom of a body of water such as the ocean. The sensor apparatus on the water bottom is comprised of sensing elements for linear particle motion, for rotational motion, for pressure measurement, for pressure gradients, and for static orientation. Stress and wavefield conditions known at the water bottom allow numerical calculations that yield enhanced spatial sampling of pressure and nominally vertical linear particle motion, up to double the conventional (based on physical sensor locations) Nyquist spatial frequency in two nominally horizontal independent directions. The method and apparatus have a wide range of application in Ocean Bottom Seismic 3D, 4D, and Permanent Reservoir Monitoring surveys, and other marine seismic surveys, in oil and gas exploration and production.

Abstract: A method for spatial sampling of a seismic wavefield at the bottom of a water layer at an effective spatial sampling denser than the physical layout of the sensors. The sensors comprise a sensing element for vertical particle motion and a sensing element for rotational motion around a horizontal axis. Stress and wavefield conditions allow the rotational sensing element to yield the transverse horizontal gradient of the vertical particle motion wavefield, used in ordinate and slope sampling to yield improved transverse spatial sampling of the vertical particle motion wavefield.

Abstract: The present method provides spatial sampling of a seismic wavefield on the free surface of the earth at an effective spatial sampling denser than the physical layout of the sensors. The sensors are comprised of a sensing element for vertical particle motion at the earth's surface, and a sensing element for rotational motion around a horizontal axis at the surface of the earth. Stress and wavefield conditions known at the free surface of the earth allow the rotational sensing element to yield the transverse horizontal gradient of the vertical particle motion wavefield. This horizontal gradient and the vertical particle motion data are utilized in the technique of ordinate and slope sampling to yield an improved transverse spatial sampling of the vertical particle motion wavefield. The method has a wide range of application in seismic surveys in oil and gas exploration and production.

Abstract: A method for detemining an optimum spacing of seismic energy sources based on mutual admittance includes deploying a plurality of seismic energy sources along a source line, separated by a selected spacing. Seismic receivers are deployed along a receiver line orthogonal to the source line. Seismic energy is simultaneously transmitted from each of the plurality of seismic energy sources while recording signals from the seismic receivers. The transmitting and recording of signals is repeated for a plurality of different spacings between the energy sources. Seismic energy in the recorded signals is determined in separate time windows selected to represent reflected body wave signal, and source generated ground roll noise, respectively. A signal-to-noise ratio with respect to the spacing of the seismic energy sources is calculated and the optimum spacing between energy sources is selected based on the signal-to-noise ratio.

Abstract: The present invention provides extensions to the sampled spatial wavenumber spectrum of a seismic wavefield on the free surface of the earth or at the bottom of a body of water to wavenumbers higher than the Nyquist limit for the physical layout spacing of the seismic sensor units. The seismic sensor units are comprised of linear sensing elements for at least linear vertical particle motion; and rotational sensing elements for rotational motion around at least one, or more, horizontal axes. Stress and wavefield conditions known on the land surface of the earth or on a water bottom allow the rotational sensing element to yield the transverse horizontal gradient of the vertical particle motion wavefield. This horizontal gradient and the linear vertical particle motion data are utilized in techniques of sample reconstruction to yield an improved horizontal spatial sampling of the linear vertical particle motion wavefield.

Abstract: The present invention provides visualization of a seismic wavefield as measured by various multi-component sensors, including, but not limited to, pressure, 3-component vector spatial pressure gradients, 3-component linear motion, and 3-component rotational motion. The visualization of the present invention employs combinations of dynamic displacement; dynamic rotation; dynamic dilation and compression; and dynamic color and transparency variations to display various measurements of a seismic wavefield. The visualization of the present invention may be applied to various seismic data sets, including, but not limited to, pre-stack data sets; post-migration data volumes; micro-seismic passive or active source monitoring; and vertical seismic profiles. The method has a wide range of application in seismic surveys in oil and gas exploration and production.

Abstract: The present invention provides a method and apparatus for enhanced monitoring of induced seismicity and industrial vibration to comprehensively measure all aspects of potentially damaging motion. The invention utilizes various combinations of multi-component low frequency linear seismic sensors and multi-component rotational seismic sensors. Sensors are jointly deployed in arrays on the free surface of the earth, and/or in arrays of shallow monitoring holes, which may be intended to be permanent deployments. The method has a wide range of risk/damage monitoring applications for industrial activity, and in oil and gas exploration and production for seismic surveys, hydraulic fracturing, and waste injection wells. This abstract is not intended to be used to interpret or limit the claims of this invention.

Abstract: Disclosed herein are various embodiments of a technique to monitor hydro-fracturing in oil and gas wells by use of active seismic sources and arrays of monitoring sensors. The invention utilizes combinations of seismic sources such as vertical vibrators in anti-phase pairs. The invention utilizes combinations of multi-component rotational seismic sensors, and/or multi-component linear sensors, and/or pressure sensors. Sensors are jointly deployed in arrays on the surface and/or in shallow monitoring wells to avoid the complicating effects of the free surface of the earth. The emplacement of sensors on the surface or in the shallow monitoring wells may be permanent. Fractures are monitored by combinations of physical effects such as propagation time delays, shear reflections, birefringent shear wave splitting, and amplitude variations. The method has a wide range of application in oil and gas exploration and production.

Abstract: Disclosed herein are various embodiments of a method and apparatus to enhance spatial sampling in all nominally horizontal directions for Dual-Sensor seismic data at the bottom of a body of water such as the ocean. The sensor apparatus on the water bottom is comprised of sensing elements for linear particle motion, for rotational motion, for pressure measurement, for pressure gradients, and for static orientation. Stress and wavefield conditions known at the water bottom allow numerical calculations that yield enhanced spatial sampling of pressure and nominally vertical linear particle motion, up to double the conventional (based on physical sensor locations) Nyquist spatial frequency in two nominally horizontal independent directions. The method and apparatus have a wide range of application in Ocean Bottom Seismic 3D, 4D, and Permanent Reservoir Monitoring surveys, and other marine seismic surveys, in oil and gas exploration and production.

Abstract: The present invention provides a technique to separate compressional seismic waves from shear seismic waves and to determine their direction of propagation to enhance the seismic monitoring oil and gas reservoirs and the seismic monitoring of hydrofracturing in oil and gas wells. The invention utilizes various combinations of multi-component linear seismic sensors, multi-component rotational seismic sensors, and pressure sensors. Sensors are jointly deployed in arrays of shallow monitoring wells to avoid the complicating effects of the free surface of the earth. The emplacement of sensors in the shallow monitoring wells may be permanent. The method has a wide range of application in oil and gas exploration and production. This abstract is not intended to be used to interpret or limit the claims of this invention.

Abstract: The present method provides spatial sampling of a seismic wavefield on the free surface of the earth at an effective spatial sampling denser than the physical layout of the sensors. The sensors are comprised of a sensing element for vertical particle motion at the earth's surface, and a sensing element for rotational motion around a horizontal axis at the surface of the earth. Stress and wavefield conditions known at the free surface of the earth allow the rotational sensing element to yield the transverse horizontal gradient of the vertical particle motion wavefield. This horizontal gradient and the vertical particle motion data are utilized in the technique of ordinate and slope sampling to yield an improved transverse spatial sampling of the vertical particle motion wavefield. The method has a wide range of application in seismic surveys in oil and gas exploration and production.

Abstract: A method for spatial sampling of a seismic wavefield at the bottom of a water layer at an effective spatial sampling denser than the physical layout of the sensors. The sensors comprise a sensing element for vertical particle motion and a sensing element for rotational motion around a horizontal axis. Stress and wavefield conditions allow the rotational sensing element to yield the transverse horizontal gradient of the vertical particle motion wavefield, used in ordinate and slope sampling to yield improved transverse spatial sampling of the vertical particle motion wavefield.