Abstract: The invention refers to antenna configurations for electromagnetic logging tools. The antennas have one or more electrical conductors disposed on a dielectric substrate wrapped around a core or disposed directly on the core. The conductor or conductors are arranged such that the antenna has a first magnetic dipole moment substantially perpendicular to a longitudinal axis of the core. The invention also refers to antennas adapted for mutual balancing using interleaved conductive paths or disks to alter the magnetic dipole moments to mutually balance the antenna system.

Abstract: A load cell for sensing deformation in a drill collar is provided. The load cell comprises a disc member having one or more arcuate apertures and a deformation sensing element disposed on a side surface of the arcuate apertures. The load cell is capable of sensing such drilling parameters as weight and torque on a drill bit during the drilling operation.

Abstract: A method of monitoring the density of a subterranean fluid comprises the steps of: using a subterranean radiation detector to obtain measurements over a plurality of time intervals of the amount of natural background radiation traversing said fluid, and calculating the relative density of said fluid at each of said time intervals from said measurements.

Abstract: Methods and apparatus are disclosed for minimizing or eliminating an undesired axial electric current induced along a subsurface borehole in the process of subsurface measurements with transmitter and/or receiver antennas which are substantially time varying magnetic dipoles with their dipole moments aligned at an angle to the axis of the borehole. Some antennas are disposed within the borehole on instruments having a non-conductive support member. One instrument includes a conductive all-metal body with an antenna adapted for induction frequencies. Antenna shields adapted for controlled current flow are also provided with an all-metal instrument. Methods include providing an alternate path for the current along the instrument body. Another method includes emitting a controlled current to counter the undesired current. Another method corrects for the effect of the current using a superposition technique.

Abstract: Methods and tools are provided for real time velocity imaging of a borehole wall with sufficiently high resolution to identify vugs, worm holes, thin beds, dip angles, fractures and breakouts, for both open hole logging and logging while drilling in the presence of OBM's. A method is provided which includes transmitting an ultrasonic pulse through the borehole wall, receiving at first and second spaced-apart receivers an ultrasonic pulse refracted from the borehole wall, and producing a velocity image data value indicative of difference of arrival times at first and second spaced-apart receivers. This is repeated at a plurality of azimuths and depths to produce a velocity image data set. The method uses compressional pulses and/or pseudo-Raleigh pulses. A tool is provided for wireline use having an ultrasonic transmitter for transmitting ultrasonic pulses into the borehole wall, and a plurality of ultrasonic receivers.

Abstract: A method for supplying a customer with well log data including obtaining wellsite properties from the customer, recommending at least one tool string and analysis software tool combination using the wellsite properties, processing well log data using customer domain information and the least one tool string and analysis software tool combination to obtain processed well log data, viewing the processed well log data using an interactive viewer, manipulating the customer domain information, and updating the processed well log data on the interactive viewer using the manipulated customer domain information.

Abstract: A gravity sensor is disclosed which includes a first mass adapted to free fall when selectively released from an initial position. The mass has optical elements adapted to change a length of an optical path in response to movement of the mass. The sensor output is coupled to a beam splitter. One output of the splitter is coupled substantially optically directly to an interferometer. Another output of the splitter is coupled to the interferometer through an optical delay line. A frequency of the interference pattern is directly related to gravity at the mass. A second such mass having similar optics, optically coupled in series to the first mass and adapted to change the path length in opposed sign, when selectively dropped to cause time coincident movement of the two masses, generates an interference pattern having frequency related to gravity difference.

Abstract: A method for designing acid treatments provides for the selection of optimal treatment for well stimulation wherein reservoir characteristics are obtained to further select the reaction kinetic data on the minerals of interests, the treatment to the reservoir is scaled up using a mathematical model and real time damage are computed based on bottomhole pressure and injection rate and compared to that predicted by the mathematical model to adjust the treatment. The model generated facilitates optimization of matrix treatments by providing a rapid quantitative evaluation of various treatment strategies for a formation. Stimulation with non-traditional fluid recipes containing mixtures of inorganic and organic acids, and chelating agents can be readily computed. The computed values can then be used in an economic model to justify the additional costs associated with the use of the non-traditional fluids.

Abstract: In a well an instrumentation line can be introduced down the well bore by a control line having at least a portion outside of intermediate casing and set in cement slurry between the intermediate casing and the surrounding rock and reaching to a zone of interest. A primary member accepts the distal end of the control line at the end of the intermediate casing. A secondary member has a terminal control line (sealed at its far end) attached on its outer surface. When in place, the secondary member extends into and through the zone of interest. When the secondary member is lowered through the primary member, its top end is lowered onto the bottom end of the primary member. Couplings engage and angularly orientate so that the top of the terminal control line couples to and seals with the distal end of the control line to form a conduit through which a fibre optic instrumentation line can be threaded.

Abstract: A downhole sampling tool and related method are provided. The tool is provided with a main flowline for communicating fluid from the formation through the tool. A main valve is positioned in the main flowline and defines a first portion and a second portion of the main flowline. At least one sample chamber with a slidable piston therein defining a sample cavity and a buffer cavity is also provided. The sample cavity is in selective fluid communication with the first portion of the main flowline via a first flowline and with the second portion of the main flowline via a second flowline. Fluid communication is selectively established between the sample cavity and the first and/or second portions of the main flowline for selectively flushing fluid through the sample cavity and/or collecting samples of the fluid therein. Fluid may also be discharged from the buffer cavity via a third flowline.

Abstract: A sonic logging tool that can be positioned within a fluid-filled borehole includes an axially distributed active vibration control system to reduce tool borne noise. The tool includes an acoustic transmitter, an axial array of acoustic receivers, and actuator assemblies that are coupled to cancel tool mode vibrations at stations along the receiver section of the tool. In a preferred embodiment, force is applied in feedback mode based on tool mode vibrations sensed at each station. The force at each station is applied by a real-time computational algorithm using feedback. The feedback includes weighting to accommodate monopole or dipole tool mode vibration. The computational algorithm includes FIR processing of signals received from a vibration sensor assembly. The force applied at a given station is a function of tool mode vibration measured at that station and the predetermined values of a set of FIR filter coefficients associated with the given station.

Abstract: A method of attenuating noise in three dimensional seismic data using a projection algorithm is disclosed. A frequency—space—space (“f-xy”) projection algorithm is used which is a generalization of the f-x projection algorithm. The predictability of the seismic signals in the f-xy domain constitutes the basis of the algorithm. Specifically it is demonstrated that if the seismic events are planar in the t-xy domain, then in the f-xy domain they consist of predictable signals in the xy-plane for each frequency f. A crucial step of the 2-D spectral factorization is achieved through the helical coordinate transformation. In addition to the disclosed general algorithm for arbitrary coherent noise, a specialized algorithm for random noise is disclosed. It has been found that the disclosed projection algorithm is effective even in extreme cases of poor signal to noise ratio. The algorithm is also signal preserving when the predictability assumptions hold.

Abstract: Determining the downhole rheological properties of a wellbore fluid. The method includes moving the wellbore fluid through a wellbore tool assembly into a wellbore at a first flow rate. A pressure is measured at a first position proximate a bottom of the wellbore. A pressure is measured at a second position in the wellbore axially separated from the first position. The wellbore fluid is then moved through the wellbore tool assembly at a second flow rate. Measuring pressure at the first and second positions is repeated, and at least one rheological property is determined from the pressure measurements.

Abstract: Cementing compositions which are particularly suitable for squeeze cementing operations, comprise an aqueous phase, and a micro-cement, the aqueous phase including an aqueous suspension comprising a vinyl acetate type polymer obtained by chemically cross-linking a polyvinyl compound, a nanolatex and an anionic surfactant with a cloud point of more than 80° C.

Abstract: A straddle packer tool for treatment of wells has a tool body supporting sealing elements in spaced relation for defining a sealed annulus zone within a wellbore. The tool body defines a treatment fluid passage having treatment ports that open to the sealed annulus zone for formation fracturing or other well treatment. The tool body has a bypass passage therethrough which is isolated from the treatment fluid passage and communicates with the wellbore above and below the sealed annulus zone. A check valve permits downward flow of well fluid from the bypass passage into the wellbore below the tool and prevents upward flow of fluid into the bypass passage. Bypass ports conduct fluid flow to and from the bypass passage and the wellbore above and below the sealed annulus zone. A packer actuated bypass valve is opened or closed to control the flow of well fluid within the bypass passage.

Abstract: A well logging instrument is disclosed which includes a housing operatively coupled to a well logging conveyance and movable within the wellbore. The housing has therein a formation testing system and an axial extension mechanism. The axial extension mechanism controllably extends and retracts to allow the formation testing system to perform tests and take samples in an axially fixed position in the wellbore while the housing moves through the wellbore.

Abstract: A well-log display (160) having a principle axis (135) matched to a deviation of a section of a well-bore (450) is disclosed. By presenting a well-log (160) at about the same angle as the section of the well-bore under consideration, a person viewing the well-log (160) will have the advantage of easily visualizing the inclination of the well-bore (450) to aid in geo-steering, proper interpretation of well-bore measurements, etc. Such a well-log (160) may be presented as a hardcopy or as an interactive display on a computer screen (642). A presentation (100, 200) of a well-log (160) may include more than just the log itself, for example, a reference diagram (100, 200) of the entire well highlighting (130) or otherwise indicating the part of the well currently being displayed in the well-log.

Abstract: A method relating to filtering coherent noise and interference from seismic data by constrained adaptive beamforming is described using a constraint design methodology which allows the imposition of an arbitrary predesigned quiescent response on the beamformer. The method also makes sure that the beamformer response in selected regions of the frequency-wavenumber space is entirely controlled by this quiescent response, hence ensuring signal preservation and robustness to perturbations. Built-in regularization brings an additional degree of robustness. Seismic signals with arbitrary spectral content in the frequency-wavenumber domain are preserved, while coherent noise and interference that is temporally and spatially nonstationary is adaptively filtered. The approach is applicable to attenuation of all types of coherent noise in seismic data including swell-noise, bulge-wave noise, ground-roll, air wave, seismic vessel and rig interference, etc. It is applicable to both linear or areal arrays.

Abstract: A robust, low-loss wired pipe joint is provided for service as a component of a wired pipe string for transmitting measurement data to a surface station from locations in a borehole in oil well drilling and oil well operations. Conductive layers reduce signal energy losses over the length of the drill string by reducing resistive losses and flux losses at each inductive coupler. The wired pipe joint is robust in that it remains operational in the presence of gaps in the conductive layer. A wired pipe joint includes an elongate tubular shank having an axial bore, a threaded box-end, and a threaded pin end.

Abstract: Apparatus for determining the density of a fluid downhole includes apparatus for measuring compressibility of the fluid and apparatus for determining the speed of sound through the fluid. According to the methods of the invention, density of the fluid is calculated based upon the relationship between density, compressibility, and the speed of sound through the fluid.