Abstract: Apparatus and methods to control fluid flow in a downhole tool are disclosed. A disclosed example system includes a hydraulically actuatable device having a cavity for receiving pressurized hydraulic fluid stored by a reservoir, a first and a second hydraulic pump, a motor and means for selectively flowing hydraulic fluid from the outlet of at least one of the first and second pumps to the at least one cavity. The first and second hydraulic pumps include an inlet fluidly coupled to the reservoir and an outlet fluidly coupled to the cavity, and the motor is operatively coupled to at least one of the pumps.

Abstract: A method of sampling fluid from a rock formation penetrated by a borehole includes positioning a downhole tool having a flow line in the borehole, establishing an inlet port through which fluid passes from a first point in the formation into the flow line, establishing an outlet port through which fluid passes from the flow line into a second point in the formation, and passing fluid between the formation and the flow line through the inlet and outlet ports.

Abstract: Methods and systems for testing a subterranean formation penetrated by a wellbore are provided. A testing tool has a plurality of packers spaced apart along the axis of the tool, and at least a testing port. The testing tool is positioned into the wellbore and packers are extended into sealing engagement with the wellbore wall, sealing thereby an interval of the wellbore. In some embodiments, the wellbore interval sealed between two packers is adjusted downhole. In one embodiment, the location of the testing port is adjusted between two packers. The methods may be used to advantage for reducing the contamination of the formation fluid by fluids or debris in the wellbore.

Abstract: Example methods and apparatus to determine the compressibility of a fluid are disclosed. A disclosed example method includes capturing a fluid in a chamber, pressurizing the captured fluid to first and second pressures, measuring first and second values representative of first and second densities of the fluid while pressurized at respective ones of the first and second pressures, and computing a third value representative of a compressibility of the fluid using the first and second values.

Abstract: A modular tool for use in subterranean formations includes a first module, a second module and one or more connectors for connecting the first and second modules. In particular, the first module includes a first collar that at least partially defines an exterior of the tool and that includes a first engagement mechanism at a first end of the collar and a second engagement mechanism at a second end of the collar. The first module also includes a fluid passageway for passing drilling fluid therethrough. The second module has a similar configuration as includes similar architecture. The one or more connectors facilitate the connection of at least one flowline fluidly connected to an exterior of the tool, and an electrical pathway for transmitting power and/or data between the modules.

Abstract: A method for determining the size of tubular pipe to be inserted into an interval of cased or uncased borehole is disclosed. The position of the borehole wall or innermost casing surface in the interval is determined and a window length that is less than the length of the interval is defined. A series of windows along the interval is defined and for each window, the determined position of the borehole wall in that window is used to define a polygon, the edges of which are defined by the parts of the borehole wall closest to the borehole axis in that window. The maximum size of pipe diameter that will fit inside the polygon in each window without intersecting the edges is determined and the size of pipe to be inserted into the interval selected based on the maximum size of diameter pipe determined for each window.

Abstract: A connector connects auxiliary flow lines—and, in some configurations, electrical lines—that extend through and terminate at or near opposing ends of two respective components of a downhole tool string. The connector comprises a body assembly for fluidly-connecting the auxiliary flow lines and electrically-connecting the electrical lines of the respective two components, and an assembly for adjusting the length of the body assembly. In particular embodiments, the two components are discrete modules of a unitary tool, or alternatively, are distinct tools. Additionally, the connector may include a mechanism for closing the auxiliary flow lines of one or both components upon disconnection of the fluid connection between the two components.

Abstract: A method includes obtaining a first set of survey data at a first point along a wellbore, estimating a present wellbore position based on at least the first set of survey data, determining a related ellipse of uncertainty at the present wellbore position, comparing the related ellipse of uncertainty of the present wellbore position to a threshold, and selecting a methodology for a subsequent survey based on a comparison of the related ellipse of uncertainty to the threshold.

Abstract: Apparatus and methods to perform focused sampling of reservoir fluid are described. An example method couples a sampling probe to a subterranean formation and, while the sampling probe is coupled to the subterranean formation, varies a pumping ratio of at least two displacement units to reduce a contamination level of a formation flu id extracted via the sampling probe from the subterranean formation.

Abstract: A formation fluid sampling tool is provided with a drill which drills into the formation in a manner perpendicular or oblique to the borehole wall. The tool comprises a mechanism for enhancing the mobility of the reservoir fluid, such as a heating element on the drill, hot fluid which is generated in the tool and injected into the drilled hole, or a solvent which is stored in the tool and injected by the tool into the drilled hole.

Abstract: A gap collar for an electromagnetic communication unit of a downhole tool positioned in a wellbore is provided. The downhole tool communicates with a surface unit via an electromagnetic field generated by the electromagnetic communication unit. The gap collar includes a first collar having a first end connector and a second collar having a second end connector matingly connectable to the first end connector. The gap collar further includes a non-conductive insulation coating disposed on the first and/or second end connectors, and a non-conductive insulation molding positioned about an inner and/or outer surface of the collars. The insulation molding moldingly conforms to the shape collars. The connectors are provided with mated threads modified to receive the insulation coating. Measurements taken by the downhole tool may be stored in memory, and transmitted to the surface unit via the electromagnetic field.

Abstract: A method for determining a drilling event includes measuring a first signal from a sensor over a first selected time interval, measuring a second signal from the sensor over a second time interval, determining if a noise is reduced in the second signal.

Abstract: A method of retrieving a formation fluid from a formation adjacent a borehole wall includes estimating at least one of a permeability of the formation and a viscosity of the formation fluid. A first tool is selected based on the estimation, the first tool being selected from one of a heating and sampling tool, an injection and sampling tool, and a coring tool. An attempt to retrieve a formation fluid sample from the formation is then made with the first tool, and a formation fluid sample is retrieved from the formation. A second retrieval process may then be initiated, in which the second retrieval process includes increasing the mobility of the formation fluid.

Abstract: A sample module for a sampling while drilling tool includes a sample fluid flowline operatively connectable between a sample chamber and an inlet, for passing a downhole fluid. A primary piston divides the sample chamber into a sample volume and a buffer volume and includes a first face in fluid communication with the sample volume and a second face in fluid communication with the buffer volume. An agitator is disposed in the sample volume for agitating the sample fluid. A secondary piston includes a first face in fluid communication with the buffer volume having buffer fluid disposed therein and a second face.

Abstract: A fluid sampling system retrieves a formation fluid sample from a formation surrounding a wellbore extending along a wellbore axis, wherein the formation has a virgin fluid and a contaminated fluid therein. The system includes a sample inlet, a first guard inlet positioned adjacent to the sample inlet and spaced from the sample inlet in a first direction along the wellbore axis, and a second guard inlet positioned adjacent to the sample inlet and spaced from the sample inlet in a second, opposite direction along the wellbore axis. At least one cleanup flowline is fluidly connected to the first and second guard inlets for passing contaminated fluid, and an evaluation flowline is fluidly connected to the sample inlet for collecting virgin fluid.

Abstract: A device to measure a fluid pressure comprises a pressure sensing element 10 and a pressure readout element 20. The pressure sensing element 10 comprises a cavity 11 capped by a flexible membrane 13, the cavity having a length d that varies with the fluid pressure P1 applied on the flexible membrane 13. The pressure readout element 20 comprises a light source 24 for providing an incident beam of a determined wavelength range directed towards the cavity and an optical spectral analyzer 25 for measuring a power spectrum of a return beam reflected by the cavity, and processing means 27 for determining the cavity length d and the fluid pressure P1 based on the power spectrum.

Abstract: An apparatus for determining the nature of the formation at the bottom of a wellbore being drilled with a tubular drill string through which drilling fluid is pumped to return the drilling fluid to the surface via the wellbore, the apparatus comprising a tool body for installation in a drill string with a bore extending there through and an ultraviolet fluorescence detector in a passageway in the tool body, the tool body being configured to receive drilling fluid from inside the drill string and to receive drilling fluid from outside the drill string, wherein the drilling fluid can be directed past the detector so as to enable measurements to be made.

Abstract: A wellbore tool for locating a target wellbore containing a conductive member from a second wellbore and directing the trajectory of the second wellbore relative to the target wellbore includes an electric current driver having an insulated gap; a three-axis magnetometer positioned within a non-magnetic housing that is disposed within a non-magnetic tubular, the three-axis magnetometer positioned below the electric current driver; a drill bit positioned below the three-axis magnetometer; a hollow tubular connected between the electric current driver and the three-axis magnetometer; and a measurement-while-drilling tool. The current driver generates an electric current across the gap to the portion of the tool below the insulated gap. In a method a current is generated across the insulated gap to the portion of the tool below the insulated gap to the conductive material in the target wellbore returning to a portion of the bottom hole assembly above the insulated gap thereby producing a target magnetic field.

Abstract: A downhole tool configured for conveyance within a wellbore extending into a subterranean formation, the tool comprising an electronics system and a heat-dissipating apparatus. The electronics system includes a controller, a memory, and surface communicating means, at least one of which is a heat-generating source. The heat-dissipating apparatus includes: a chassis engaging the heat-generating source and having a fluid passageway allowing fluid flow therethrough; a radiator for further heat dissipation; a pump; sensors to measure temperature of the chassis and the wellbore; and a compensator to regulate the pressure of fluid in the passageway.

Abstract: Systems and methods in which data compression techniques are utilized to fill a predetermined channel capacity are shown. According to one configuration, event data points within test data are selected for communication via the data communication channel and a data decimator is utilized to identify other data points within the test data to fill or substantially fill the predetermined channel capacity. The foregoing data decimator may employ one or more variables for selecting data for communication, wherein one or more of the variables are preferably adjusted in decimator iterations to select an optimum or otherwise desirable subset of data for communication. Data decimators may additionally or alternatively implement a suitable “growth” function to select the particular data for communication and/or the amount of data communicated.