Abstract: The specification discloses a downhole tool that determines hydraulic permeability of a downhole formation taking into account one or both of the dip angle of the borehole relative to the formation, and damage to the borehole wall and invasion of borehole fluid—collectively referred to as skin.

Abstract: A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity and a reference cavity. In one embodiment, the measurement device includes a sample flow tube, a reference flow tube, vibration sources and detectors mounted on the tubes, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The reference flow tube is filled with a reference fluid having well-characterized properties. The measurement module employs the vibration sources to generate vibrations in both tubes. The measurement module combines the signals from the vibration detectors on the tubes to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example.

Abstract: A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity. In one embodiment, the measurement device includes a sample flow tube, vibration source and detector mounted on the tube, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The measurement module employs the vibration sources to generate vibrations in the tube. The measurement module combines the signals from the vibration detector on the tube to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example. To measure the sample fluid density, the measurement module determines the resonant frequency of the sample flow tube. The density can then be calculated according to a formula that compensates for the temperature and pressure of the system.

Abstract: A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity and a reference cavity. In one embodiment, the measurement device includes a sample flow tube, a reference flow tube, vibration sources and detectors mounted on the tubes, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The reference flow tube is filled with a reference fluid having well-characterized properties. The measurement module employs the vibration sources to generate vibrations in both tubes. The measurement module combines the signals from the vibration detectors on the tubes to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example.

Abstract: A fluid property monitor includes a transducer assembly to impart multiple frequency energy to a conduit in one or more modes and to receive resonant frequency energy from the conduit. The resonant frequency energy is responsive to the imparted energy, the conduit and a fluid in the conduit. The fluid property monitor can also be defined as including: a frequency signal generator connected to cause multiple frequency energy to be transferred to a conduit having a fluid to be monitored; and a spectral analysis signal processor connected to receive and process electrical signals generated in response to vibrations propagated through the conduit and the fluid in the conduit in response to transferred multiple frequency energy. Particular implementations can be adapted as a densitometer, a coherent flow detector, and other particular fluid parameter detectors.

Abstract: The present invention discloses a process and apparatus for treating a wellbore, comprising subjecting a substantially same portion of the wellbore to vibratory waves produced by a plurality of vibratory wave generators. The vibratory waves may have about the same frequency or a plurality of frequencies, and the frequencies may partially overlap, not overlap, or be modulated across a range. Additionally, the frequencies may be modulated in an oval, hoop, and flexural modes. The vibratory waves may be produced by firing the vibratory wave generators simultaneously or in sequence. Preferably, the vibratory waves are acoustically streamed in a viscous boundary layer near obstacles, outside a viscous boundary layer near obstacles, or in a free non-uniform sound field. In a preferred embodiment, a vibrating pipe and a piston pulser are used as vibratory wave generators. In another preferred embodiment, a vibrating pipe, piston pulser, and a valve are used as vibratory wave generators.

Abstract: A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity and a reference cavity. In one embodiment, the measurement device includes a sample flow tube, a reference flow tube, vibration sources and detectors mounted on the tubes, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The reference flow tube is filled with a reference fluid having well-characterized properties. The measurement module employs the vibration sources to generate vibrations in both tubes. The measurement module combines the signals from the vibration detectors on the tubes to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example.

Abstract: A formation fluid sampling probe uses two hydraulic lines to recover formation fluids from two zones in a borehole. One of the zones is a guard zone and the other is a probe zone. The guard zone and the probe zone are isolated from each other by mechanical means, with the guard zone surrounding the probe zone and shielding it from the direct access to the borehole fluids. Operation of the tool involves withdrawal of fluid from both zones. Borehole fluids are preferentially drawn into the guard zone so that the probe zone recovers the formation fluid substantially free of borehole fluids. Separation of the guard zone from the probe zone may be accomplished by means of an elastomeric guard ring, by inflatable packers or by tubing. The device can be adapted for use either on a wireline or in an early evaluation system on a drillstring.

Abstract: This invention provides a formation evaluation tool for collecting a formation fluid in a chamber at a predetermined pressure and for maintaining the pressure of the collected fluid at a desired level during the retrieval of the chamber to the surface. The formation fluid is pumped into the chamber while a piston exposed to the hydrostatic pressure maintains the chamber pressure at the hydrostatic pressure. During retrieval of the chamber, the pressure in the chamber is maintained at a predetermined level by pumping wellbore fluid to the piston. A control unit at the surface is utilized for controlling the operation of the formation tool.

Abstract: A system for determining fluid flow characteristics and relaying the information to the surface. The system is ideal for use in horizontal or deviated wellbores since orientation of the wellbore with respect to the vertical will not appreciably affect the system's operation. In the described embodiment, a fluid-driven siren flowmeter is placed within a production string downstream of the location of a completion zone, the flowmeter relays representative information downstream via a fluid column to a signal detection assembly. The flowmeter includes a stationary stator, a rotatable rotor and a turbine deflector which is positioned upstream of the rotor and angularly directs the flow of passing fluid to rotate the rotor. In the case of multiple completed zones described, multiple flowmeters are sequentially mounted along the same production string, each providing signals of different characteristics.

Abstract: This invention provides a closed-loop system for in situ testing of formation fluid conditions and for selectively collecting substantially mud filtrate free formation fluid samples at original formation conditions. The system contains an elongated member having a probe that is sealingly placed against the wellbore formation to withdraw formation fluids. A surface controlled pump controls the flow of a fluid from the formation into a flowline placed in the elongated member. A pressure sensor provides downhole hydrostatic pressure and an acoustic density cell provides the speed of sound in the fluid, acoustic impedance of the fluid and acoustic absorption coefficient of the fluid in the flowline. The system determines the density and compressibility of the formation fluid in the flowline from the speed of sound in the fluid and acoustic impedance of the fluid. The formation of the bubbles are identified or detected from the acoustic absorption coefficient of the fluid in the flowline.

Abstract: A new technique for interpreting pressure data measured during a formation test. The new technique uses an exact spherical flow model that considers the effects of flow line storage and that can be solved in closed, analytical form. This technique generates a type-curve that matches the entire measured pressure plot and that can accurately predict ultimate formation pressure during formation testing from a pressure plot that has not achieved steady state values near the formation pressure.

Abstract: The present invention provides an apparatus and method for determining geologic formation properties. A pressure wave is generated by a reciprocating piston transmitted to the formation by a probe. The pressure is sensed by a high accuracy quartz gauge in the probe. This pressure is compared to the pressure sensed at a spaced probe or to the flow rate of the piston to calculate permeability or other formation properties.

Abstract: An improved formation testing method increases the accuracy of in-situ formation pressure measurements by characterizing the mudcake properties. Specifically, after a formation tester is lowered to a desired depth within a wellbore, a pad is extended to gently abut and seal against the mudcake without disturbing the mudcake. When pressed against the mudcake, the pad experiences momentarily higher pressures, which are measured by a probe housed by the pad. These pressures may be enhanced by briefly rejecting fluids through the probe, so as to avoid disturbing the mudcake. The probe continues to measure pressure, which eventually decreases relative to hydrostatic pressure in the wellbore, due to the flow of high-pressure wellbore fluids through the mudcake.

Abstract: An improved formation testing method for measuring initial sandface pressure and formation permeability in tight zone formations exhibiting formation permeabilities on the order of 1.0-0.001 millidarcies based on pressure transients which occur shortly after the tester enters its pressure buildup cycle and substantially before reaching final buildup pressure. The method makes an estimate of formation permeability based on fluid decompression transients which occur in the formation tester flowlines which occur shortly after the tester begins its buildup cycle. The method further estimates initial sandface pressure based on the change in pressure over time shortly after beginning the buildup phase. The method of the present invention thereby permits accurate estimates of formation permeability and initial sandface pressure to be made relatively early in the buildup cycle, thus substantially reducing the time required to make the pressure and permeability measurements.

Abstract: An improved rotary power shear that includes an electric motor which drives, through a reduction gear assembly, a rotary shear assembly comprised of a driving shear wheel which rotates against a cooperating driven shear wheel. The design of the tool is characterized by a handle that extends above the motor housing and gear casing, and which supports the tool at one end from the gear casing and at the other end from the rear of the motor housing. In this manner the tool is balanced when held by the handle as the weight of the gear casing and cutting assembly at the forward end of the tool offsets the weight of the motor at the rearward end of the tool. In addition, the design of the tool is facilitated by the provision of a single bracket member that serves the multiple functions of supporting and biasing together the rotary shear wheels, providing a cover for the gear casing, and also providing a support for the stub shafts on which the gears are journalled.