Abstract: An optical sensor for pH is described using a cross-linked network of bisilanes to immobilize a pH sensitive chromophore to a surface potentially exposed to a high pressure, high temperature environment such as wellbore effluents at a downhole location.

Abstract: This invention provides rotating electrical connections and methods of using the same. One aspect of the invention provides a rotating electrical connection. The rotating electrical connection includes: a rotary member and a pin. The rotary member includes a contact surface and is configured for rotation about a rotational axis. The rotational axis intersects with the contact surface. The pin is configured to contact the rotary member at the intersection of the rotational axis and the contact surface.

Abstract: Tubewaves are used for detection and monitoring of feature state to enhance stimulation operations and remediate failure conditions. For example, proper sealing of perforations may be confirmed based on lack of a reflection of a tubewave by the perforations. Alternatively, at least one of amplitude, frequency, attenuation, dispersion and travel time associated with a tubewave and reflection may be used to determine feature state. If a sealant fails during treatment then the failure condition is indicated by appearance of a tubewave reflection. Consequently, the stimulation operation can be stopped in a timely manner, and remediation by means, for example, of pumping diversion fluid or dropping of balls, can be reinitiated until the difference between the expected responses and responses measured by the instrument along the segment to be stimulated confirm that sealing has taken place and that stimulation of the intended zone can resume.

Abstract: Methods and apparatuses to direct a drill bit of a directional drilling assembly are disclosed. The methods and apparatuses employ the use of bi-directional actuators that are capable of displacing a hybrid steering sleeve in positive and negative directions. The bi-directional actuators are capable of greater control and precision in their actuations than traditional “engaged-disengaged” unidirectional actuators, thereby allowing for more precise directional drilling operations. The bi-directional actuators are preferably driven by drilling fluids and may optionally be shielded to lessen the erosive effects thereof.

Abstract: A method comprising using inelastic and capture gamma-ray count rates from two detectors in a borehole logging tool and determining formation water saturation. In this method the formation water saturation is determined without prior knowledge of the carbon density in the pore hydrocarbons.

Abstract: Methods and systems are provided where a production gas stream including natural gas and carbon dioxide is separated downhole using dual reflux pressure swing adsorption with the natural gas being produced and the carbon dioxide being directed for downhole storage (sequestration).

Abstract: The permeability of the cement annulus surrounding a casing is measured by locating a tool inside the casing, placing a probe of the tool in hydraulic contact with the cement annulus, measuring the change of pressure in the probe over time, where the change in pressure over time is a function of among other things, the initial probe pressure, the formation pressure, and the permeability, and using the measured change over time to determine an estimated permeability. By drilling into the cement and making additional measurements of the change of pressure in the probe over time, a radial profile of the cement permeability can be generated.

Abstract: The permeability of the cement annulus surrounding a casing is measured by locating a tool inside the casing, placing a probe of the tool in contact with the cement annulus, measuring the change of pressure in the probe over time, where the change in pressure over time is a function of among other things, the initial probe pressure, the formation pressure, and the permeability, and using the measured change over time to determine an estimated permeability. The estimated permeability is useful in determining whether carbon dioxide can be effectively sequestered in the formation below or at the depth of measurement without significant leakage through the cement annulus.

Abstract: A method and apparatus for electrically interfacing between two or more distinct environments. The method and apparatus are directed to an electrical feedthru with exterior traces traversing a core. The electrical feedthru may be very small, facilitating its use in MEMS devices. The electrical feedthru may also include an over-mold shaped to create a mechanical seal between the two or more distinct environments without the use of an O-ring. The electrical feedthru is not limited to any particular geometry, it may be adapted to fit between any two environments, and thus the traces are not necessarily parallel to a central axis of the core.

Abstract: Carbon dioxide is sequestered in a formation using a dual completion and injection method that reduces or eliminates upward leak rates of the sequestered carbon dioxide. The dual completion and injection method involves the injection of a benign fluid such as brine (water) into a permeable layer of the formation located above the sequestration layer and which is separated form the sequestration layer by a nearly impermeable layer. The water is preferably injected at the same time the carbon dioxide is injected.

Abstract: Exhaust pressure from at least one actuator (34,36) which can tilt joint 6 of a bottom hole assembly 4 can be utilized to determine the direction 26 tiltable joint 6 is pointing (e.g., orientation, angular displacement, and/or inclination and azimuth). In one embodiment, a known exhaust pressure can be correlated to a known orientation and/or angular displacement, and the measured exhaust pressure can be compared to the known exhaust pressure to determine the orientation and/or angular displacement. In another embodiment, the flow rate of fluid exhausted from an actuator (34,36) can be derived from the exhaust pressure. The exhaust flow rate can then be used to calculate the state of actuation, which can allow determination of the angular displacement of the tiltable joint 6. Orientation and/or angular displacement with respect to the bottom hole assembly 4 can be resolved into an inclination and azimuth with respect to a formation 14.

Abstract: A method and apparatus for providing, e.g., identifying or determining, at least one parameter of a fluid moving through a fluid channel using a vibrating wire in contact with the fluid moving through the fluid channel that is clamped under tension. The vibrating wire is actuated by an actuating device capable of displacing the vibrating wire from an initial position. An interpretation element further is utilized to provide a parameter of the fluid moving through the fluid channel based upon data from the vibrating wire following actuation by the actuation element.

Abstract: The invention concerns an apparatus for analysing water chemistry. According to the invention, the apparatus is adapted to operate downhole and comprises a colouring agent supply device for supplying a colouring agent to a water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and a colorimetric analyser arranged to determine the colour of the water sample.

Abstract: A new approach is described based on reciprocity for estimating acquisition-related effects, which has several advantages over conventional surface-consistent processing techniques: (i) It can be applied to complete recordings, hence does not require the isolation of primary reflections in the data, (ii) no assumptions are imposed on the subsurface, and (iii) it is applicable to multi-component data. The application of reciprocity requires symmetric data acquisition, i.e. identical source and receiver patterns, identical locations, and the source orientations have to be identical to the receiver components. Besides reciprocity, additional constraints are required to determine the lateral source and receiver amplitude variations fully. Criteria based on minimizing total energy differences between adjacent common source and common receiver gathers, and in common offset panels of the medium response are applied.

Abstract: A method and apparatus is disclosed for identifying changes in composition in a flow containing an oil/hydrocarbon gas fluid mixture, including a measurement of the respective holdups of any two of the gas, oil and water; and measurements to determine attenuation or scattering of high energy photons passing through the mixture; and combining holdup measurements and attenuation or scattering measurements to detect the presence or concentration of a hetero-component in the mixture.

Abstract: A bottom hole assembly has a drill bit and an under-reamer on the up-hole side of the drill bit. In one aspect, the assembly further has a compliant element linking the drill bit to the under-reamer, the compliant element allowing displacement of the drill bit relative to the under-reamer in the axial direction of the assembly. In another aspect, the assembly further has a sensor element which is arranged to measure the weight-on-bit and/or the applied torque of the drill bit, and a transmitter for transmitting the weight-on-bit and/or applied torque measurements to the surface.

Abstract: A method to estimate water saturation (Sw) of a thin-bedded formation is provided including (a) developing a model of anisotropy of resistivity (Rv/Rh) a function of water saturation (Swt) for one or more volume fractions (either Fshale or Fsand); (b) measuring the anisotropy of resistivity of the formation; (c) measuring the volume fraction of the formation; (d) correlating anisotropy of resistivity to the measured volume fraction of the formation using the model to estimate the water saturation (total water saturation or sand water saturation) of the formation.

Abstract: Earth formations are characterized by using an array of electrodes which can measure streaming potentials in the formation, and by interpreting the data obtained by the electrodes. The electrodes are placed on a wireline tool, a LWD tool, or in a fixed manner about a completed wellbore. The measured streaming potentials are generated by drilling with an overbearing pressure, slitting the mudcake in a borehole, acid injection, or any of various other manners which causes fluid movement. The data obtained is interpreted to locate fractures, measure formation permeability, estimate formation pressure, monitor drilling fluid loss, detect abnormal pressure, etc. Particularly, a streaming potential voltage transient having a double peak profile signifies the presence of a formation fracture.

Abstract: An oil sample is subjected to nuclear electromagnetic irradiation downhole, and the electron and/or mass density of the oil sample is determined by measuring the attenuation of the irradiation and relating the attenuation to the electron density. If the irradiation is high energy gamma ray irradiation, the attenuation is considered to be a function of Compton scattering only, which in turn is related to the electron density of the sample. If X-rays are utilized, attenuation is preferably measured in two energy windows. Using the two different attenuation values found in the different windows, the attenuation due to Compton scattering can be found and related to the electron and/or mass density of the sample. In addition, attenuation due to photoelectric absorption may also be determined and related to the presence of one or more heavy elements in the oil (e.g., sulfur) and/or sanding.