Abstract: A method for performing fluid influx tests in a wellbore comprises inserting a well test device into the wellbore such that it separates a well test section from other sections of the wellbore; performing a first fluid influx test during which fluid pressure in the test section is reduced, pore fluid is induced to flow into the test section and fluid influx into the test section is monitored; injecting a completion fluid into the test section, and inducing the completion fluid to flow into the formation; performing a second fluid influx test during which fluid pressure within the test section is reduced, completion and pore fluids are induced to flow into the test section, and fluid influx into the test section is monitored; comparing fluid influx monitoring data acquired during the fluid influx tests to determine any effects of the completion fluid on formation pore fluid influx into the test section.

Abstract: A method for performing fluid influx tests in a wellbore (3) traversing a permeable formation (4) to test the compatibility of one or more completion fluids comprises: a) inserting a well test device (1) comprising a straddle packer assembly (6A,6B) into the wellbore (3) such that the straddle packer assembly (6A,6B) separates a well test section (13) from other sections of the wellbore; b) performing a first fluid influx test during which the fluid pressure the test section (13) is reduced, pore fluid is induced to flow from the pores of the permeable formation (4) into the test section (13) and fluid influx into the test section (13) is monitored; c) injecting a completion fluid into the test section (13), thereby increasing the fluid pressure within the test section and inducing the completion fluid to flow into the pores of the surrounding formation (4); d) performing a second fluid influx test during which the fluid pressure within the test section (13) is reduced, the completion fluid and pore fluid are

Abstract: An apparatus and methods for acoustically analyzing a fluid sample and determining one or more properties of the sample are disclosed by the present invention. The apparatus comprises a chamber, a transmitter positioned within the chamber for transmitting an acoustic signal through the fluid, a reflector movably positioned within the fluid inside the chamber for reflecting the acoustic signal, and a receiver positioned within the chamber for detecting reflections of the acoustic signal. The methods employ the use of a transmitter, a reflector movably positioned within the fluid inside the chamber, and a receiver to characterize the fluid sample based on one or more of its acoustic properties.

Abstract: Determining the viscosity of a hydrocarbon reservoir fluid that is present in a formation layer traversed by a borehole, which method involves the steps of selecting a location in the formation layer; lowering in the borehole to the location a tool that has a central conduit having an inlet, means for displacing fluids through the central conduit, and an optical fluid analyzer; making an exclusive fluid communication between the formation and the inlet of the central conduit; obtaining a spectrum of the optical density; calculating a first factor that is the maximum optical density in a predetermined short-wavelength range multipled with the length of the short-wavelength range, calculating a second factor which is the integral over the same short-wavelength range of the spectrum, subtracting the second factor from the first factor to obtain a hydrocarbon oil property; and obtaining the magnitude of the in-situ viscosity from the oil property using a relation that has been obtained by fitting a curve through

Abstract: A method for retrieving a formation fluid sample through a cased borehole utilizing a sampling tool. Sampling tool straddle packers are set about a first set of perforations and annular fluid is drained from the isolated zone, through a central conduit in the tool and discharged above or below the packers. Formation fluid is induced to flow into the central conduit and into sample chambers. The packers are unset, the tool moved to the next set of perforations that are azimuthally offset from the first set of perforations and the sampling process repeated, with subsequent samples being placed in separate sample chambers.

Abstract: A method for determining the in-situ effective mobility of hydrocarbons in a formation layer, in which a formation test tool, having a fluid analyzer, induces sample fluid to flow from the formation, the sample being analyzed and discarded where it includes fluid from the invaded zone, so as to perform the pressure test on uncontaminated formation fluid.

Abstract: Determining the in situ effective mobility of a formation layer comprises selecting a location in the formation layer; lowering in the borehole traversing the formation layer a tool that comprises a central conduit having an inlet and being provided with a pressure sensor, a fluid receptacle having an inlet opening into the central conduit. a fluid analyser, and means for discharging fluid; making an exclusive fluid communication between the formation and the inlet of the central conduit; allowing formation fluid to pass through the central conduit, analysing the fluid, allowing the formation fluid to enter into the fluid receptacle when the fluid is the substantially uncontaminated formation fluid, and measuring the pressure build-up: and determining the effective mobility from the pressure build-up.

Abstract: The invention relates to a coin (1) which has a metallic surface (2, 3) and comprises macroscopic reliefs (5) that serve to visually indicate the value of the coin and as a legitimacy feature. Microscopically fine relief structures (8) that cause diffraction are placed directly inside at least one of the surfaces (2, 3). The relief structures (8) are preferably recessed and covered with a lacquer (9). In addition, it is advantageous when at least one portion of the relief structures (8) has an asymmetrical profile shape and/or the lattice vectors are radially aligned. The relief structures (8) can also contain a machine-readable coding which is recognized by cost-effective optical reading devices to be installed in coin examiners. The microscopic relief structure (8) can be provided on a hard material surface (2, 3) by removing material effected by exposing the material surface (2, 3) to a laser beam.

Abstract: Retrieving a sample of formation fluid from a formation layer traversed by a cased borehole comprising making a plurality of perforation sets through the casing wall into the formation layer, wherein the orientation of the perforation sets is so selected that the angle between adjacent perforation sets equals 360° divided by the number of perforation sets; lowering a sampling tool into the borehole to the first perforation set; taking a sample from the formation and storing the sample in the first fluid sample container; positioning the sampling tool near the next perforation) set, taking a sample from the formation and storing the sample in the next fluid sample container; and repeating the latter step until samples from all perforation sets have been taken, and retrieving the sampling tool.

Abstract: Deteriming the viscosity of a hydrocarbon reservoir fluid that is present in a formation layer traversed by a borehole, which method comprises the steps of selecting a location in the formation layer; lowering in the borehole to the location a tool that comprises a central conduit having an inlet, means for displacing fluids through the central conduit, and an optical fluid analyser; making an exclusive fluid commuication between the formation and the inlet of the central conduit; obtaining a spectrum of the optical density; calculating a first factor that is the maximum optical density in a predetermined short-wavelenght range multiplied with the length of the short-wavelenght range, calculating a second factor which is the integral over the same short-wavelength range of the spectrum, subtracting the second factor from the first factor to obtain a hydrocarbon oil porperty; and obtaining the magnitude of the in situ viscosity from the oil property using a relation that had been obtained by fitting a curve (1

Abstract: Measuring the in situ temperature of a formation traversed by a borehole comprising lowering to a predetermined position in the borehole a tool that comprises a central conduit having an inlet an dbeing provided with a temperature sensor in contact with the fluid, means for analysing the fluid, and means for discharging fluid; allowing only formation fluid to pass through the central conduit; analysing the formation fluid; and measuring the temperature when the formation fluid is substantially uncontaminated.