Abstract: A marine vibrator with improved seal is described. The marine vibrator includes a housing and piston within the housing for generating vibratory signals. The improved seal is comprised of a two-stage seal having a first seal disposed adjacent the water interface and a second seal disposed away from the water interface, thus improving the reliability of the marine vibrator.

Abstract: An apparatus and a method for characterizing parts of a reservoir surrounding a borehole are provided including using at least one transmitter to emit a probing signal into the borehole and at least one receiver to receive a signal representing a response of the formation to the probing signal, with the distance separating the transmitter and the receiver being variable while suspended in the borehole using for example an apparatus which can be decoupled in the borehole into a stationary and a mobile section, carrying transmitter and receiver.

Abstract: An in-line flow separator comprises an uphill section of pipeline which, in use, carries a gravitationally stratified flow of a first liquid and a second denser liquid. The second liquid forms a sump extending uphill from the foot of the uphill section, and an interface between the first and second liquids on the uphill section is inclined from the horizontal. An extraction port in the pipeline extracts the second liquid from the sump.

Abstract: An efficient and cost-effective technique is provided to perform modeling of a reservoir in a subterranean structure. A compartment model of fluid compartments in a reservoir is generated, and based on the compartment model and a geomechanical model of the subterranean structure, movement of a ground surface due to volumetric change of the compartments is calculated. Satellite measurements of the ground surface are received over time, where the received satellite measurements of the ground surface over time indicate movement of the ground surface. The movement of the ground surface indicated by the received satellite measurements is compared with the calculated movement, and based on the comparing, one or more properties of the geomechanical model are adjusted.

Abstract: A marine vibrator with improved seal is described. The marine vibrator includes a housing and piston within the housing for generating vibratory signals. The improved seal is comprised of a two-stage seal having a first seal disposed adjacent the water interface and a second seal disposed away from the water interface, thus improving the reliability of the marine vibrator.

Abstract: A subsurface formation monitoring system and method is described. The system includes a conductive piping structure positionable within a borehole extending into a subsurface formation. The conductive piping structure is electrically decoupled from a production tubing by an insulating packer. The system also includes a downhole installed conductive casing sub that has one or more sensors. The conductive casing sub is electrically coupled to the conductive piping structure. The system further includes a surface installed power and communication module that has an alternate current generator. The power and communication module is electrically coupled to the conductive piping structure via a downhole intermediate module. The alternate current generator can inject a current signal that flows downhole to the conductive casing sub and then returns with sensor measurements to the surface power and communication module via a grounded return electrode that is coupled to the subsurface formation.

Abstract: An in-line flow separator comprises an uphill section of pipeline which, in use, carries a gravitationally stratified flow of a first liquid and a second denser liquid. The second liquid forms a sump extending uphill from the foot of the uphill section, and an interface between the first and second liquids on the uphill section is inclined from the horizontal. An extraction port in the pipeline extracts the second liquid from the sump.

Abstract: An in-line flow separator (1) comprises an uphill section (2) of pipeline which, in use, carries a gravitationally stratified flow of a first liquid (3) and a second denser liquid (4). The second liquid (4) forms a sump (5) extending uphill from the foot of the uphill section (2), and an interface between the first and second liquids on the uphill section is inclined from the horizontal. An extraction port (6) in the pipeline extracts the second liquid from the sump.

Abstract: A sensor cable for surveying. The sensor cable may comprise at least one pair of current sensor electrodes and an amplifier. The current sensor electrodes may be disposed along opposite sides of the sensor cable. The current sensor electrodes may be configured to detect current in an electromagnetic field transverse to an inline direction of the sensor cable. The amplifier may be configured to amplify the current in the electromagnetic field for detection by the electrode pair.

Abstract: A subsurface formation monitoring system and method is provided. The system comprises a conductive piping structure having a conductive tubing, a surface installed power and communication module coupled to the conductive piping structure, and a downhole installed conductive tubing sub.

Abstract: A method for determining a formation electrical property under a sea floor includes obtaining measurement data using a receiver having an impedance lower than an impedance of seawater at a measurement site; correcting the measurement data to obtain corrected data corresponding to data that would have been acquired using a receiver having an impedance matched with the impedance of the seawater; and deriving the formation property from the corrected data.

Abstract: A method for determining formation electrical properties includes deploying one or more receivers for electromagnetic logging; obtaining measurement data indicative of the formation electrical properties using the deployed receivers; correcting the measurement data for receiver imperfection; and inverting the corrected measurement data to obtain one or more parameters of formation electrical properties.

Abstract: An apparatus and a method for characterizing parts of a reservoir surrounding a borehole are provided including using at least one transmitter to emit a probing signal into the borehole and at least one receiver to receive a signal representing a response of the formation to the probing signal, with the distance separating the transmitter and the receiver being variable while suspended in the borehole using for example an apparatus which can be decoupled in the borehole into a stationary and a mobile section, carrying transmitter and receiver.

Abstract: A subsurface formation monitoring system comprises a conductive piping positioned within a borehole extending into the formation, a surface installed power and communication module, a downhole installed conductive casing or tubing sub comprising sensor(s) mounted on the sub, a data communication module for wireless communication of sensor measurements to the surface module, and a battery for providing power to the data communication module and the sensor. The surface module is coupled to the conductive piping and to a grounded return electrode coupled to the formation, and comprises an alternate current generator that defines an ingoing signal path along the conductive piping and sub, the ingoing signal flowing from the surface module to the sub and transmitting power from the generator to the sub. A return signal comprising sensor measurements is transmitted through a return signal path flowing from the sub to the surface module.

Abstract: An efficient and cost-effective technique is provided to perform modeling of a reservoir in a subterranean structure. A compartment model of fluid compartments in a reservoir is generated, and based on the compartment model and a geomechanical model of the subterranean structure, movement of a ground surface due to volumetric change of the compartments is calculated. Satellite measurements of the ground surface are received over time, where the received satellite measurements of the ground surface over time indicate movement of the ground surface. The movement of the ground surface indicated by the received satellite measurements is compared with the calculated movement, and based on the comparing, one or more properties of the geomechanical model are adjusted.

Abstract: A receiver for electromagnetic measurements includes a polyhedron structure having m faces, where m?4 and m?6: n electrodes each disposed on one face of the polyhedron structure, wherein 3?n?m; and at least one circuitry connected to the n electrodes for signal measurement. A method for electromagnetic measurements includes obtaining a plurality of electric current measurements using a plurality of electrodes each disposed on a surface of a polyhedron receiver, wherein the plurality of electric current measurements comprise at least three different measurements; and determining electric field components in a three dimensional space from the plurality of electric current measurements by using a number of matrices that correlate orientations of surfaces of the polyhedron receiver to a coordinate system in the three dimensional space.

Abstract: A sensor cable for surveying. The sensor cable may comprise at least one pair of current sensor electrodes and an amplifier. The current sensor electrodes may be disposed along opposite sides of the sensor cable. The current sensor electrodes may be configured to detect current in an electromagnetic field transverse to an inline direction of the sensor cable. The amplifier may be configured to amplify the current in the electromagnetic field for detection by the electrode pair.

Abstract: A subsurface formation monitoring system comprises: a conductive piping structure 2 comprising either a conductive casing or a non conductive casing fitted with a conductive tubing, the conductive piping being positioned within a borehole BH extending into the subsurface formation GF, a surface installed power and communication module 3, and a downhole installed conductive casing or tubing sub 4A, 4B, 4C comprising at least one sensor 5, 15 mounted on the sub, a data communication module 6 for wireless communication of the sensor measurements to the surface installed power and communication module, and a powering means 7 for providing power to the data communication module 6 and the sensor 5, 15.

Abstract: A method for determining formation electrical properties includes deploying one or more receivers for electromagnetic logging; obtaining measurement data indicative of the formation electrical properties using the deployed receivers; correcting the measurement data for receiver imperfection; and inverting the corrected measurement data to obtain one or more parameters of formation electrical properties.

Abstract: An electromagnetic receiver includes at least one sensor for measuring electromagnetic signals, and a calibration antenna configured to generate an electromagnetic signal at a first frequency.