Abstract:
Techniques for evaluating physical aspects of a formation fluid from within a wellbore include changing at least one of a pressure on and a temperature of a sample of the formation fluid and transmitting at least one acoustic pulse through the fluid sample and analyzing acoustic information collected. Apparatus and methods for the evaluating involve using at least one acoustic transducer. Analyzing typically involves use of formulae that relate equation (s) of state and other properties for the fluid to a change in the sound speed in the fluid.
Abstract:
In one embodiment an apparatus is disclosed that includes a tool in a wellbore. A probe is extendable from the tool to contact a wall of a formation surrounding the wellbore. A tube substantially surrounds the probe wherein the tube is extendable into the formation surrounding the wellbore. In another embodiment a method for reducing contamination of a sample of a formation fluid is disclosed that includes extending a probe to contact a wall of a formation. A barrier tube that substantially surrounds the probe is extended into the formation thereby restricting a flow of a contaminated reservoir fluid that would otherwise come from near-wellbore regions above and below the probe from going toward the probe.
Abstract:
The present invention provides method and apparatus for quantifying sample clean up in real time by providing curve-fitting measurements of optical or other physical properties of fluid downhole. Fluid is extracted from the formation surrounding a borehole. As fluid continues to be extracted the composition of the extracted fluid changes, altering the measured values of optical and physical properties of the fluid. Measurements are made of optical or physical properties of the sampled fluid, analysis is performed on the acquired measured data points.
Abstract:
A formation fluid sample is exposed to a rigidly-supported semi-permeable membrane such as silicone rubber to permit diffusion of gases and vapors from the formation fluid into a vacuum chamber, while at the same time, blocking the passage of any liquids. The membrane-transmitted gas is analyzed in the vacuum chamber by a sorbent-coated resonator. The sorbent absorbs gas and changes the resonant frequency of the resonator to indicate the presence of a gas. An ion pump or sorbent is associated with the evacuated chamber to maintain the vacuum. The ion pump or sorbent removes gases and vapors from the chamber that diffuse into the chamber from the reservoir sample that is on the opposite side of the semi-permeable membrane.
Abstract:
The present invention provides a simple, robust, and versatile high-resolution spectrometer that is suitable for downhole use. The present invention provides a method and apparatus incorporating a spinning, oscillating or stepping optical interference filter to change the angle at which light passes through the filters after passing through a sample under analysis downhole. As each filter is tilted, the color or wavelength of light passed by the filter changes. Black plates are placed between the filters to isolate each filter's photodiode. The spectrometer of the present invention is suitable for use with a wire line formation tester, such as the Baker Atlas Reservation Characterization Instrument to provide supplemental analysis and monitoring of sample clean up. The present invention is also suitable for deployment in a monitoring while drilling environment. The present invention provides a high resolution spectometer which enables quantification of a crude oil's percentage of aromatics, olefins, and saturates to estimate a sample's gas oil ratio (GOR). Gases such as CO2 are also detectable. The percentage of oil-based mud filtrate contamination in a crude oil sample can be estimated with the present invention by using a suitable training set and chemometrics, a neural network, or other type of correlation method.
Abstract:
In a particular embodiment, a method is disclosed for determining a source of a fluid downhole. The method includes deploying an ion selective sensor downhole, exposing the fluid to the ion selective sensor downhole, measuring an ion concentration at different places within the fluid and using that information to identify a source of the fluid from the ion concentration profile. In another particular embodiment, an apparatus is disclosed for estimating a source of a fluid. The apparatus contains a tool deployed in a well bore, an ion selective sensor in the tool, a processor in communication with the ion selective sensor and a memory for storing an output from the ion selective sensor.
Abstract:
The disclosure, in one aspect, provides a method for estimating a property of a fluid that includes: pumping an ultraviolet (UV) light into a fluid withdrawn from a formation downhole at a wavelength that produces light due to the Raman effect at wavelengths that are shorter than the substantial wavelengths of fluorescent light produced from the fluid; detecting a spectrum corresponding to the Raman effect light (“Raman spectrum”); and processing the detected Raman spectrum at one or more selected wavelengths to estimate a property of the fluid. In another aspect, the disclosure provides an apparatus that includes a laser that induces UV light at a selected wavelength into a fluid in a chamber, a detector that detects Raman scattered light at wavelengths shorter than the wavelengths of the fluorescent light scattered by the fluid, and a processor that analyzes a spectrum corresponding the Raman scattered light at a selected wavelength to estimate a property of the fluid.
Abstract:
The present invention provides an down hole apparatus and method for ultrahigh resolution spectroscopy using a tunable diode laser (TDL) for analyzing a formation fluid sample downhole or at the surface to determine formation fluid parameters. In addition to absorption spectroscopy, the present invention can perform Raman spectroscopy on the fluid, by sweeping the wavelength of the TDL and detecting the Raman-scattered light using a narrow-band detector at a fixed wavelength. The spectrometer analyzes a pressurized well bore fluid sample that is collected downhole. The analysis is performed either downhole or at the surface onsite. Near infrared, mid-infrared and visible light analysis is also performed on the sample to provide an onsite surface or downhole analysis of sample properties and contamination level. The onsite and downhole analysis comprises determination of aromatics, olefins, saturates, gas oil ratio, API gravity and various other parameters which can be estimated by correlation, a trained neural network or a chemometric equation.
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. A hard or inorganic coating is placed on the flexural mechanical resonator (such as a tuning fork) to reduce the effects of abrasion from sand particles suspended in the flowing fluid in which the flexural mechanical resonator is immersed.
Abstract:
A cooling system in which an electronic device or other component is cooled by using one or more solid sources of liquid vapor (such as polymeric absorbents, hydrates or desiccants that desorb water at comparatively low temperature) in conjunction with one or more high-temperature vapor sorbents or desiccants that effectively transfer heat from the component to the fluid in the wellbore. Depending on the wellbore temperature, desiccants are provided that release water at various high regeneration temperatures such as molecular sieve (220–250° C.), potassium carbonate (300° C.), magnesium oxide (800° C.) and calcium oxide (1000° C.). A solid water source is provided using a water-absorbent polymer, such as sodium polyacrylate. Heat transfer is controlled in part by a check valve selected to release water vapor at a selected vapor pressure.