Schlumberger Technology Corporation

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Bradley Albert Roscoe

Christian Stoller

James A Grau

Markus Berheide

Zilu Zhou

Kenneth Edward Stephenson

Peter D Wraight

Robert A Adolph

Michael Lynn Evans

Felix K Chen

Olivier G Philip

Donald C McKeon

James Leslie Thornton

Charles R Case

Martin E Poitzsch

Christopher Harrison

Keith A Moriarty

Tong Zhou

Benoit Couet

Matthieu Simon

Michael M Herron

Martin G Luling

Douglas W Grant

Darwin V Ellis

Jeffrey S Schweitzer

Wolfgang P Ziegler

Susan L Herron

John J Simonetti

Richard G Saenger

Benjamin Levitt

Jacques M Holenka

Joyce Wong

Arthur J Becker

Paul Albats, Jr

William A Loomis

William R Sloan

Timothy Spillane

Joshua Wayne Gibson

Chloe Coleou

Jing Qian

Jerome A Truax

Christopher Peter Lenn

S Zema Chowdhuri

Yanqi Wang

A well logging instrument includes a radiation generator and a high voltage power supply functionally coupled to the generator. The generator and the supply are longitudinally separated by a distance sufficient for emplacement of a radiation detector. At least a first radiation detector is disposed in a space between the generator and the supply. The instrument includes an electrical connection between the supply and the generator.

Radiation generator and power supply configuration for well logging instruments

Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties. A preferable detector choice is one where the required measurement precision (logging speed) is obtained for all of the required inelastic elements and/or minimization of unwanted background signals that complicate the data analysis.

Gamma-ray detectors for downhole applications

A gravimeter, a gravimeter system, and a method for measuring gravitational acceleration within a borehole are described herein. The gravimeter includes a proof mass that is constrained by springs and an optical interferometer for measuring displacement of the proof mass. The optical interferometer generates a light path from a light source to a reflective surface on the proof mass. Spatial displacement of the proof mass from a reference position to a position of gravitational equilibrium is determined by measuring a change in length of the light path. In turn, gravitational acceleration can be determined from the spatial displacement of the proof mass. A number of such gravimeters can be used in a gravimeter system to make measurements of gravitational acceleration in variety of different directions.

Systems, devices and methods for borehole gravimetry

Systems, methods, and devices for thermally protecting a scintillator crystal of a scintillation detector are provided. In one example, a thermally-protected scintillator may include a scintillator crystal and a thermal protection element, which may partially surround the scintillator crystal. The thermal protection element may be configured to prevent the scintillator crystal from experiencing a rate of change in temperature sufficient to cause cracking or non-uniform light output, or a combination thereof.

Thermally-protected scintillation detector

Systems and methods for neutron porosity well logging with high precision and reduced lithology effects are provided. In accordance with an embodiment, a downhole neutron porosity tool may include a neutron source, a neutron monitor, a neutron detector, and data processing circuitry. The neutron source may emit neutrons into a subterranean formation while the neutron monitor detects a count of neutrons proportional to the neutrons emitted. The neutron detector may detect a count of neutrons that scatters off the subterranean formation. The data processing circuitry may determine an environmentally corrected porosity of the subterranean formation based at least in part on the count rate of neutrons scattered off the subterranean formation normalized to the count rate of neutrons proportional to the neutrons emitted by the neutron source.

Neutron porosity downhole tool with improved precision and reduced lithology effects

Borehole logging tools and systems that include a scintillator positioned to interact with scattered source neutrons that are received from a target formation. The scintillator emits luminescence in response to interaction with the scattered neutrons. The scintillator includes an aluminofluoride host material (e.g., LiCAF). In a specific embodiment, the aluminofluoride host material is doped with europium. In a further specific embodiment, a processor distinguishes scattered neutrons from gamma rays based upon identifying a peak within an output signal from the scintillator. In yet another specific embodiment, a system includes a first scintillator and a second scintillator. The processor subtracts luminescence generated by the second scintillator from luminescence generated by the first scintillator to identify a neutron response of the first scintillator.

Scintillator-based neutron detector for oilfield applications

Apparatus and method for detecting radiation-of-interest, such as neutron radiation, employs a gas chamber, a gas that responds to ionizing particles by producing electrons and ions, a cathode that attracts ions, and a supporting layer with a conductive pathway. The conductive pathway collects electrons and responds to electrons that drift towards the conductive pathway by inducing production of further electrons and ions within the gas. The electrons that are collected at the conductive pathway and/or the ions that drift away from the conductive pathway will induce an electrical signal, which can be used to detect the radiation-of-interest.

Apparatus and method for detecting radiation

Systems, methods, and devices for determining a porosity of a subterranean formation corrected for borehole effects are provided. One such device may be a downhole tool capable of being lowered into a borehole of a subterranean formation that may include a neutron source, two or more neutron detectors, and data processing circuitry. The neutron source may emit neutrons into the subterranean formation. The two or more neutron detectors may be respectively disposed at two or more azimuthal orientations within the downhole tool, and may detect neutrons scattered by the subterranean formation or borehole fluid in the borehole, or both. Based on the neutrons detected by the neutron detectors, the data processing circuitry may determine a porosity of the subterranean formation corrected for borehole effects.

System and method for correction of borehole effects in a neutron porosity measurement

A nuclear tool includes a tool housing; a neutron generator disposed in the tool housing; and a solid-state neutron monitor disposed proximate the neutron generator for monitoring the output of the neutron generator. A method for constructing a nuclear tool includes disposing a neutron generator in a tool housing; and disposing a solid-state neutron monitor proximate the neutron generator for monitoring the output of the neutron generator. A method for logging a formation includes disposing a nuclear tool in a wellbore penetrating the formation, wherein the nuclear tool comprises a neutron generator and a solid-state neutron monitor disposed proximate the neutron generator; generating neutrons from the neutron generator; monitoring neutrons generated by the neutron generator using the solid-state neutron monitor; detecting signals generated from the neutrons traveling in the formation; and correcting the detected signals, based on signal strength detected by the solid-state neutron monitor, to produce corrected signals.

Downhole tools with solid-state neutron monitors

Devices, methods, and related systems are described for measuring a property of a fluid, including density, in a subterranean environment. A device includes a pressure housing having one or more windows formed in the pressure housing and a flow device arranged in the pressure housing for the fluid to flow through the flow device. Further, a radiation source is mounted within the pressure housing approximate a first source window configured to generate particles into the fluid. The device includes a detector supported by the pressure housing and positioned approximate a first detector window of the one or more windows. The first detector window is located between the detector and the flow device. The detector can be a solid state beta particle detector with a wide band gap, such as the diamond detector, and the radiation source can be a beta particle source, such as a strontium 90 source.

Fluidic density measurements based on beta particles detection

Methods and related systems are described for the detection of nuclear radiation. The system can include a scintillator material that intrinsically generates radiation and a photodetection system coupled to the scintillator material and adapted to generate electrical signals based on light emitted from the scintillator material. A processing system adapted and programmed to receive the electrical signals, to generate a count rate reference value based at least in part on electrical signals generated in response to the light emitted from the scintillator material due to the intrinsically generated radiation.

Intrinsic radioactivity in a scintillator as count rate reference

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Ridgefield, CT, United States of America

Bradley Albert Roscoe