Schlumberger Technology Corporation

Schlumberger-doll Research

Masafumi Fukuhara

Robert L Kleinberg

Abdurrahman Sezginer

Hitoshi Sugiyama

Douglas D Griffin, Ii

Brian W Cho

Shunetsu Onodera

Ahmed Al-Jubori

Weng C Chew

Alexander F Zazovsky

Rogerio Tadeu Ramos

Fernando Garcia-Osuna

Toru Ikegami

William E Kenyon

Takeaki Nakayama

Tatsuki Endo

Yoko Morikami

Damon Richard Roberts

Timur Zharnikov

Gbenga Onadeko

Ian Peirce

Yamid Pico

Kasumi Fujii

Dmitry Belov

Evgeniya Myalo Deger

Mauricio Tejada

Abdurranhman Sezginer

Peter I Day

Max Lipsicas

Peter Coupe

A technique facilitates geophysical exploration and comprises deploying an optical fiber in a borehole formed in a formation. A seismic signal, e.g. seismic waves, is excited into the formation, and an optical interrogation system is used to obtain data at a plurality of fixed, sampling locations along the optical fiber. The data is processed to determine features in the formation. Based on the processed data, updated sampling locations are selected along the optical fiber to enable further analysis of the features of interest.

Seismic sensing with optical fiber

The method of a mud cake thickness determination provides sending short high-frequency signals into a formation from at least two positions located at different distances from the mud cake and recording arrival times of reflected echo signals. The mud cake thickness is determined based on the time measured.

Method for a mud cake thickness determination

A system and method are provided for determining wall thickness of a structure such as a metallic pressurized pipe. The system includes an optical fiber having a plurality of Fiber Bragg Gratings (FBGs), and a mounting for securing the FBGs over discrete portions of the exterior surface of the pipe such that strain in the pressurized pipe wall is transmitted to the FBGs. The system further includes a light source and a light sensor coupled to an end of the optical fiber. The light sensor converts light reflected back from the FBGs into electrical signals that a digital processor converts into strain measurements. The FBGs are mounted around portions of the pipe expected to have significant metal loss as well as portions of the pipe expected to have negligible metal loss. The method includes at least one of comparing relative strains at locations with negligible metal loss to those with significant metal loss to accurately determine the thickness of the wall with metal loss; compensating for temperature effects by considering relative strains at areas of the pipe with and without metal loss; and measuring axial strain on the pipe with one or more of the FBGs to correct for at least one of bending and torsion effects on hoop strain.

System and method for uniform and localized wall thickness measurement using fiber optic sensors

A method and system for monitoring any incursion of particulate matter from a gas hydrate formation into a well casing used for the production of the gas hydrate and determining the degree of incursion of particulate material within the distal end of the well casing.

Method and system for monitoring the incursion of particulate material into a well casing within hydrocarbon bearing formations including gas hydrates

Methods and systems of measuring in-situ time variant temperature for subsurface formations utilizing an active heating and/or cooling device and temperature sensors for purposes of characterizing hydrocarbon-bearing formations by deriving formation thermal properties.

Systems and methods of downhole thermal property measurement

Deploying systems and methods for deploying a plurality of seismic devices into a borehole comprising a cable including a plurality of inter-connected cable segments and ellipsoid seismic units with at least two rows of offset seismic protrusions to establish at least three points of contact between the seismic units and adjacent cylindrical surface of a borehole casing.

Method and apparatus for deploying a plurality of seismic devices into a borehole and method thereof

A method and system for the production of a gas hydrate including the steps of drilling into a subterranean gas hydrate formation and at least partially depressurizing the gas hydrate formation to permit separation of gas and water from the hydrate form. The gas and water is then pumped from the formation and recovered from the well. At least a portion of water pumped from the well is water that is introduced into the well from the surface or reintroduced by a feed back loop from the production operation.

Method and system for development of hydrocarbon bearing formations including depressurization of gas hydrates

A sonic logging method involves the pre-processing of a detection signal by a downhole processing device to determine the arrival time of a sonic signal at a receiver which is then transmitted to the surface. A suitable sonic logging downhole tool includes a control device for controlling generation and reception of the sonic signal, an A-D converter for digitizing the detected signal at a predetermined sampling interval, a first memory for storing the digitized waveform, a second memory for storing a program for processing the digitized waveform, and a microprocessor capable of executing the stored program so as to determine an arrival time of the sonic signal arriving at the receiver.

Sonic data logging system

Borehole logging system

An apparatus is disclosed for investigating nuclear magnetic resonance properties of earth formations traversed by a borehole, including a logging device adapted for longitudinal movement in the borehole. The device includes a first subsystem for producing a static magnetic field in the formations and a second subsystem for transmitting electromagnetic energy into the formations and for detecting electromagnetic energy from the formations. The second subsystem comprises an antenna assembly which includes an open-ended shell formed of a magnetically permeable material. An open-ended electrically conductive body is disposed within the shell and is spaced therefrom. A medium whose acoustic impedance is substantially different than the acoustic impedance of the shell and the body is disposed between the shell and the body. An electrically conductive probe is disposed in the body, and an electrically insulating magnetically permeable loading material disposed in the body. The shell is formed of a material having a magnetic permeability that is high enough to render the magnetic reluctance of the loading material several times the magnetic reluctance of the shell. The body is formed of a metal having thickness that is at least several skin depths in said metal at the frequency of the electromagnetic energy and is less than the minimum thickness that would support an acoustic resonance mode in its thickness direction at the frequency of the electromagnetic energy. The apparatus provides a shunt path for the static magnetic field in the region of the antenna that would otherwise have a deleterious effect on the loading material of the antenna and on antenna operation. The apparatus also minimizes undesirable ringing of the antenna.

Antenna and wear plates for borehole logging apparatus

Borehole NMR logging apparatus and methods, and methods for the interpretation thereof. A logging tool is provided which produces a strong, static and homogeneous magnetic field B.sub.0 in a Volume of an adjacent formation on one side of the tool to measure nuclear magnetic resonance characteristics thereof. In the preferred embodiment, the tool has an RF antenna mounted on the outside of the metal body of the tool, directing focussed oscillating magnetic fields B.sub.1 at said Volume to polarize or tip the magnetic moments of hydrogen nuclei of fluids within rock pores. The same antenna can be used to receive signals of proton precession in the Volume of interest immediately after transmission of the RF polarizing field B.sub.1. Extremely rapid damping of the antenna between the transmitting and receiving modes of operation is accomplished by a Q-switch disclosed herein. The invention provides for the direct measurement of NMR decay having transverse relaxation time T.sub.2 behavior, and further provides for the fast repetition of pulsed measurements from within a borehole. An additional magnet array may be mounted offset from the first magnet configuration to prepolarize a formation before it is measured in order to pre-align a larger number of protons than the single magnet configuration could do by itself. Additional features of the invention are disclosed which increase the Signal/Noise ratio of the measured data, and improve the quality and quantity of borehole NMR measurements, per unit of time spent. Disclosed interpretation methods determine fluid flow permeability and longitudinal relaxation time T.sub.1 -type parameters by directly comparing the measured decay signals (such as T.sub.2 or T.sub.2 * type decay) to a representation which responds to both the decay time t.sub.dec and the imposed polarization period prior to such decay t.sub.poi. The parameters of amplitude and T.sub.1 are determined and combined with certain preferred methods to generate robust values of formation characteristics such as fluid flow permeability. Other related methods are disclosed.

Borehole measurement of NMR characteristics of earth formations

Borehole NMR logging apparatus and methods, and methods for the interpretation thereof. A logging tool is provided which produces a strong, static and homogeneous magnetic field B.sub.0 in a Volume of an adjacent formation on one side of the tool to measure nuclear magnetic resonance characteristics thereof. In the preferred embodiment, the tool has an RF antenna mounted on the outside of the metal body of the tool, directing focussed oscillating magnetic fields B.sub.1 at said Volume to polarize or tip the Magnetic moments of hydrogen nuclei of fluids within rock pores. The same antenna can be used to receive signals of proton precession in the Volume of interest immediately after transmission of the RF polarizing field B.sub.1. Extremely rapid damping of the antenna between the transmitting and receiving modes of operation is accomplished by a Q-switch disclosed herein. The invention provides for the direct measurement of NMR decay having transverse relaxation time T.sub.2 behavior, and further provides for the fast repetition of pulsed measurements from within a borehole. An additional magnet array may be mounted offset from the first magnet configuration to prepolarize a formation before it is measured in order to pre-align a larger number of protons than the single magnet configuration could do by itself. Additional features of the invention are disclosed which increase the Signal/Noise ratio of the measured data, and improve the quality and quantity of borehole NMR measurements, per unit of time spent. Disclosed interpretation methods determine fluid flow permeability and longitudinal relaxation time T.sub.1 -type parameters by directly comparing the measured decay signals (such as T.sub.2 or T.sub.2 * type decay) to a representation which responds to both the decay time t.sub.dec and the imposed polarization period prior to such decay, t.sub.poi. The parameters of amplitude and T.sub.1 are determined and combined with certain preferred methods to generate robust values of the formation characteristics such as fluid flow permeability. Other related methods are disclosed.

An NMR pulse sequence for use in the borehole environment is provided which combines a modified fast inversion recovery (FIR) pulse sequence with a series of more than ten, and typically hundreds, of CPMG pulses according to

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Sagamihara, Japan

Masafumi Fukuhara