Process and apparatus for coupled electromagnetic and acoustic stimulation of crude oil reservoirs using pulsed power electrohydraulic and electromagnetic discharge
Pulsed power sources are installed in one or more wells in the reservoir interval. The pulse sources include (1) an electrohydraulic generator that produces an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir, and an acoustic pulse from the plasma vaporization of water placed around the source that propagates through the reservoir at the speed of sound in the reservoir and (2) an electromagnetic generator that produces only an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir. The electromagnetic pulse produces a high frequency vibration of the reservoir that is active at the scale of the pores in the rock that acts to decrease the effective viscosity of the oil and lower the resistance of the crude oil to flow, and the acoustic pulse from the plasma effect enhances the mobility of the crude further. The combination of electrohydraulic and electromagnetic generators in the reservoir causes both the acoustic vibration and electromagnetically-induced high-frequency vibrations occur over an area of the reservoir where stimulation is desired. Single generators and various configurations of multiple electrohydraulic and electromagnetic generators stimulate a volume of reservoir and mobilize crude oil so that it begins moving toward a producing well. The method can be performed in a producing well or wells, an injector well or wells, or special wells drilled for the placement of the pulsed power EOR devices. The method can be applied with other EOR methods such as water flooding, CO2 flooding, surfactant flooding, diluent flooding in heavy oil reservoirs.
The invention includes a geographical sensor apparatus for use under water in the sea, including a plurality of seismic sensors (1) for sensing seismic waves associated with underground formations, and a plurality of EM-sensors constituted preferably by electrodes (4) for sensing electromagnetic waves associated with the underground formations. In a preferred receiver cable configuration embodiment of the invention, the geophysical sensor apparatus includes a seismic receiver cable with a linear array of a plurality of seismic sensors (1) and EM-sensors arranged inside a flexible outer skin (25), with the EM-sensors having electrodes on the outside of the outer skin. The cable is operated on the seafloor by a surface vessel, the vessel towing an electromagnetic transmitter antenna in addition to the seismic source.
The present invention is directed to an apparatus and method for coring a borehole in a hard rock sidewall of a well bore in a subterranean formation for testing purposes. The apparatus includes a drive motor for operation down hole, a flexible drive shaft coupled to the drive motor and a coring bit coupled to the flexible drive shaft, such that the coring bit is directly driven by the drive motor. The apparatus also includes a control circuit for controlling advancement of the coring bit into the subterranean formation. The apparatus also includes a rotating carousel for storing multiple core samples. The method includes the steps of activating the drive motor to rotate the output shaft; coupling the output shaft of the drive motor to the flexible drive shaft and rotating the coring bit with the flexible drive shaft.
This invention provides a method for improving oil recovery, preferably a high-viscosity oil relying on gravity drainage, by applying vibrational energy. A fracture is created at a wellbore and a fluid displacement device is inserted at or near the fracture opening. The optimum oil mobilization frequency and amplitude is determined. The fluid inside the fracture is oscillated to a prescribed range of frequency and amplitude to improve oil production. Applications for using the fracture as a delivery device for vibrational energy to enhance performance of the steam-assisted gravity drainage process, vapor-extraction gravity drainage, or cyclic steam process are provided. An application to improve recovery of heavy oil by aquifer drive or peripheral waterflood is also provided.
A method for generating acoustic waves, the method having the steps of: extending a tine from a support structure so that a proximal end of the tine is attached to the support structure and a distal end of the tine is uninhibited; positioning an oscillator so as to be supported by the support structure and to mechanically communicate with the tine; and oscillating the tine with the oscillator.
An apparatus for generating acoustic waves, the apparatus having: a support structure; two tines extending from the support structure so that proximal ends of the two tines are attached to the support structure so that distal ends of the two tines are positioned with standoffs relative to a dimension of the support structure and the distal ends of the two tines are uninhibited, wherein the two tines each comprise a moment arm; and an oscillator in mechanical communication with the two tines.
