Abstract: Methods for estimating formation pressure from data taken during the drawdown cycle are presented. In one aspect, a method of determining a formation pressure during drawdown of a formation comprises sampling fluid from a formation using a downhole tool having a sample volume and a fluid sampling device. At least one time dependent parameter of interest related to the fluid is determined during the drawdown. The at least one time dependent parameter is analyzed using a plurality of calculation techniques to determine the formation pressure. The techniques include (i) a first pressure derivative technique; (ii) a second pressure derivative technique; (iii) a formation rate analysis technique; (iv) a dp/dt-ratio technique; and (v) a stepwise drawdown technique.

Abstract: Apparatus and methods for sensing one or more physical parameters at a remote location while minimizing or eliminating contact between reservoir fluids and the like at the remote location and the sensor used to sense the physical parameters. In one example arrangement, the apparatus includes a tubing containing a communication cable and a sensor in communication with the cable, the sensor being located within the tubing proximate the remote location. The apparatus is configured to impose a barrier of a fluid between the sensor and the environment at the remote location. A fluid barrier reservoir containing the barrier fluid is also provided in some example arrangements.

Abstract: The present invention discloses a method and apparatus to detect bubbles in a fluid sample to determine if gases are present, wherein an ultrasonic source is used and its properties monitored. Fluctuations in the ultrasonic source's electrical properties indicate the presence of bubbles/gas. Alternatively, the ultrasonic source may be used to cavitate the sample and induce the nucleation of bubbles. In such a system/method, bubbles may be detected by either (1) monitoring the ultrasonic source properties, (2) monitoring the compressibility of the sample, (3) monitoring the sample properties, including harmonics and subharmonics. The method and apparatus disclosed herein may be used in a borehole such as with a sampling means (including either a flowing sample or a stationary sample) or in a surface lab.

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: A well fluid sampling tool (5) having a sample chamber (315) at least partly contained within an at least partially evacuated jacket (160, 165, 170), the outermost wall (160) of the jacket (160, 165, 170) being adjacent to or forming an outermost wall of the tool (5). In such a tool (5) the evacuated jacket (160, 165, 170) acts to maintain the sample as originally retrieved, e.g. in single phase form (at original temperature).

Abstract: A downhole connate water sample drawn from the formation surrounding a well is validated when mud filtrate concentration is acceptably low. A preferred method includes drilling the well with a water-based drilling fluid, or more generally a water-based mud (WBM), containing a water-soluble dye. The dye acts as a tracer to distinguish connate water from WBM filtrate in a downhole sample of formation fluid contaminated by mud filtrate from the water-based mud. Preferably, an optical analyzer in a sampling tool measures light transmitted through the downhole sample to produce optical density data indicative of dye concentration. Preferably, optical density is measured at a first wavelength to obtain a first optical density, and at a second wavelength, close in wavelength to the first wavelength, to obtain a second optical density. First and second optical density data are transmitted to the surface.

Abstract: An apparatus is provided comprising a first tubular having an inside surface and outside surface defining an outside diameter; a second tubular concentric with the first tubular, the second tubular having an inside surface defining an inside diameter greater than the outside diameter of the first tubular, an outside surface, and a longitudinal axis; a plurality of spacers between the first and second tubulars, each spacer having a longitudinal axis parallel to the longitudinal axis of the second tubular, wherein at least one spacer is hollow; and at least one data sensing device and/or at least one data collecting device and/or at least one data transmitting device is carried within the at least one hollow spacer.

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: The present invention provides a tool and method for obtaining at least one parameter of interest such as pressure of a subterranean formation in-situ. The tool comprises a carrier member for conveying the tool into a borehole, at least one selectively extendable member mounted on the carrier member for separating the annulus into a first portion and a second portion, a first port exposable to formation fluid in the first portion, a second port exposable to a fluid containing drilling fluid in the second portion, a first sensor for determining a first value indicative of a first portion characteristic, a second sensor for determining a second value indicative of a second portion characteristic referenced to the first value.

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: 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: This invention provides saturated and unsaturated Vadose zone remote sample acquisition and in-situ contaminant character identification. The invention is addressed to the management of the Vadose zone. Matters of interest to the agricultural community may include, in addition to other factors, the quantity of nutrients in the saturated zone and the existence of contaminants and the potential for loss of nutrients to the unsaturated zone. Matters of interest to facilities engaging in pollution, toxic or other contaminant detection will be the presence of such contaminants in both the saturated and unsaturated zones and additionally of the transit of contaminants into the unsaturated zone having potential of interaction with the water table.

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: A formation fluid sampling apparatus (40) for verification of monophasic samples is disclosed. The apparatus (40) comprises a housing (42) having a sampling chamber (48) and a sampling port (50) defined therein. The sampling port (50) is in communication with the sampling chamber (48) and the formation traversed by the wellbore such that formation fluids may be collected in the sampling chamber (48). A temperature monitoring device (52) monitors the temperature of the formation fluids collected in the sampling chamber (48). A temperature recorder (46) that is operatively connected to the temperature monitoring device (52) is used to record the temperature fluctuations of the formation fluids in the sampling chamber (48) to determine whether the formation fluids undergo phase change degradation during collection of the fluid sample and retrieval of the formation fluid sampling apparatus (40) from the wellbore.

Abstract: An in situ underground sample analyzing apparatus for use in a multilevel borehole monitoring system is disclosed. A casing assembly comprising a plurality of elongate tubular casings (24) separated by measurement port couplers (26) is coaxially alignable in a borehole (20). The measurement port couplers (26) include an inlet measurement port (70b) for collecting fluid from an underground measurement zone (32) and an outlet measurement port (70a) for releasing fluid into the measurement zone (32). An in situ sample analyzing probe (124) is orientable in the casing assembly. The in situ sample analyzing probe (124) includes inlet and outlet probe ports (148b and 148a) alignable and mateable with the inlet and outlet measurement ports (70b and 70a). The inlet and outlet measurement ports (70b and 70a) typically include valves.