Abstract: The present invention finds the acoustic impedance of the drilling fluid using reflections from a precise metal disk, and therefrom the density of the drilling fluid. Because the reverberation characteristics of an acoustic wave depend in part on the acoustic wave shape, the first reflection from the metal disk may be used to calibrate the measurement. A method for determining a borehole fluid property is disclosed that includes (i) generating an acoustic signal within a borehole fluid, (ii) receiving reflections of the acoustic signal from the fluid, and (iii) analyzing a reverberation portion of the acoustic signal to determine the property. The analyzing of the reverberation portion may include obtaining a theoretical reverberation signal and relating the measured reverberation signal with the theoretical reverberation signal to determine the borehole fluid property.

Abstract: Micro-Electro Mechanical Systems (MEMS) based fluid sensors adapted to measure physical properties of oilfield reservoir fluids under downhole conditions. Certain embodiments of the invention may be characterized as a MEMS based reservoir fluid sensor adapted for downhole conditions having a planar member machined from a substrate material, an electrical conductor formed at least partly on the planar member; and a gauge formed on the planar member and adapted to measure a physical effect on the planar member, the physical effect being indicative of a property of a fluid in contact with the planar member.

Abstract: The present invention provides a downhole method and apparatus using a flexural mechanical resonator, for example, a tuning fork to provide real-time direct measurements and estimates of the viscosity, density and dielectric constant of formation fluid or filtrate in a hydrocarbon producing well. The present invention additionally provides a method and apparatus for monitoring cleanup from a leveling off of viscosity or density over time, measuring or estimating bubble point for formation fluid, measuring or estimating dew point for formation fluid, and determining the onset of asphaltene precipitation. The present invention also provides for intercalibration of plural pressure gauges used to determine a pressure differential downhole.

Abstract: Systems and methods particularly suitable for open hole formation testing are provided. In a described embodiment, a method of performing a test on a formation intersected by a wellbore includes the steps of flowing fluid into an apparatus from the formation, displacing a fluid barrier of the apparatus in one direction, flowing the formation fluid out of the apparatus and back into the formation by applying pressure to the apparatus, and displacing the fluid barrier in an opposite direction.

Abstract: A method and apparatus for retrieving magnetic casing fragments from a well using a shrouded magnet are disclosed. Retrieving casing fragments allows the determination of weight loss from the casing to assist in analyzing the integrity and the condition of the casing and to determine whether more expensive analysis is required. The shrouded magnet, that is formed by a non-magnetic container enclosing a source of magnetic field, recovers metal casing fragments by attracting them and other magnetic materials from oil and gas well fluids passing by the shrouded magnet device, which fragments are easily separated from the device by removing the source of magnetic field from the container.

Abstract: This invention relates to flowable devices and methods of utilizing such flowable devices in wellbores to provide communicate between surface and downhole instruments, among downhole devices, establish a communication network in the wellbore, act as sensors, and act as power transfer devices. The flowable devices are adapted to move with a fluid flowing in the wellbore. The flowable device may be memory device or a device that can provide a measure of a parameter of interest or act as a power transfer device. The flowable devices are introduced into the flow of a fluid flowing in the wellbore. The fluid moves the device in the wellbore. If the device is a data exchange device, it may be channeled in a manner that enables a device in the wellbore to interact with the memory device, which may include retrieving information from the flowable device and/or recording information on the flowable device. The sensor in a flowable device can take a variety of measurement(s) in the wellbore.

Abstract: An instrument and method for surveying the static fluid column of a cased oil well and measuring the volume of oil and brine in the fluid column is disclosed. The instrument uses the inherent differences in specific gravity between water, oil and brine to provide a more simple, convenient, portable and cost effective means for surveying oil columns in cased oil wells. The instrument includes a probe, and a modified fishing rig used to lower and raise the probe into the oil well. The fishing rig includes a handled rod, a reel with a numeric line counter, and length of fused braided fishing line. The numeric line counter visually indicates the length of line expelled from the reel's spool. The probe includes a tubular casing, which is filled with ordinary tap water. The probe is constructed and filled with water so that it has a specific gravity greater than oil and less than brine (approximately 1.0 g/cc).

Abstract: System and method for controlling fluid flows in one or more oil and/or gas wells in a geological formation, the wells each comprising a production tube, the formation containing a water-containing volume with a higher water level, comprising: one or more measuring devices, each mounted in relation to a chosen zone of a well for measuring the distance to the water level in the zone, one or more valve devices comprised in the production tubes for regulating the fluid flow from the surrounding formation to the production tube, one or more control units connected to each of the valves for regulating then on the basis of the measured distance or distances.

Abstract: A well monitoring apparatus for burial in the ground to sample and monitor subsurface water having a cylindrical bailer unit with an internal reservoir chamber for collection of samples communicated thereto from outside the bailer. A pressurization system allows for selected pressurization of the chamber from a remote location to transmit fluid therform to a remote location for inspection. The bailer may be buried separately or attached to the lower end of a conventional well casing.

Abstract: An improved method to detect water influx using video monitoring of a cased wellbore is disclosed. A wireline well tool having a video camera and a light source is lowered into a selected borehole interval where water influx is suspected. The borehole fluid over the selected interval is displaced and replaced with either a water transparent mixture containing a viscosifying agent, a coloring agent and/or sufficient salt to increase mixture density; or a transparent water insoluble solvent. By use of either of these displacement fluids, the quality of video monitoring over the selected borehole interval for water influx, is enhanced.

Abstract: An apparatus for performing a function in a flowing fluid includes an apparatus body and a drag member associated with the apparatus body. The drag member is configurable between drag configuration for moving with the fluid wherein the apparatus has a first drag and a reduced drag configuration for moving against the fluid wherein the apparatus has a second drag which is less than the first drag.

Abstract: The present invention provides a method for improving the quality of a formation fluid sample by taking the sample at a time when the formation fluid composition contains the most favorable portion of hydrocarbons. This task is accomplished by determining in real-time, the composition of the fluid flowing into a downhole tool from the formation. This method determines the optical density of the fluid as the fluid flows through the tool. An optical density spectrum is generated from the optical density measurement. The optical density spectrum is compared to a composite optical density spectrum generated from a database of known fluid samples. As a result of the comparisons, there is a determination of the derivations between corresponding features of the two spectra. Adjustments are made to the components of the composite spectrum until the deviations between the two spectra are at an acceptable minimum.

Abstract: A system for evaluating multiphase fluid flow in a wellbore. Two distinct AC signals are injected into a fluid. One AC signal originates from a transmitter electrode in ohmic contact with the fluid, and the other AC signal originates from a transmitter electrode capacitively coupled to the fluid. The geometric factors between the electrode pairs are selected to distinguish between different constituents within the wellbore fluids. The output electrical impedance of the ohmic transmitter is low so that the AC signal from the capacitive transmitter is shunted to signal ground in electrically conductive fluids. A single detector can measure the fraction of electrically conductive water covering the detector electrode as well as the dielectric constant of an oil and gas mixture. Arrays of such detector electrodes can measure the holdups and velocities of the constituent fluids in a flowing multiphase fluid.

Abstract: A device for sensing and recording downhole data relating to an ambient environment in a production well and a method for obtaining such downhole data utilizing the device. Further, the device is used in combination with a downhole pump, and preferably, in combination with a strainer for the downhole pump. The device is connected with the downhole pump, and particularly the strainer, such that the device and the downhole pump may be conveyed or transported within, and retrieved from, the production well together or as an integral unit.

Abstract: Subsurface wellbore conditions are measured directly in the wellbore while the fluid circulation system is not pumping. The measured values are recorded at the subsurface location and subsequently transmitted to the well surface when circulation is resumed using fluid pulse telemetry (FPT). Real-time measurements made when the fluids are circulating are transmitted real time using FPT. Axially spaced measurements are used to obtain differential values. The apparatus of the invention comprises an assembly carried by a drill string that is used to selectively isolate the area within the well that is to be evaluated. The apparatus includes an assembly having axially spaced inflatable well packers that are used to isolate an uncased section of the wellbore. The apparatus is equipped with self-contained measuring and recording equipment, a fluid receiving reservoir, circulation valving, measurement while drilling equipment, and automated controls.