Schlumberger Technology Corporation

Noriyuki Matsumoto

Jimmy Lawrence

Bikash Kumar Sinha

Tsutomu Yamate

Go Fujisawa

Shigeo Daito

Sophie Nazik Godefroy

Michael M Toribio

Martine Hori

Oliver Clinton Mullins

Kai Hsu

Li Jiang

Christopher Harrison

Kentaro Indo

Anthony Frank Veneruso

Christopher Del Campo

Nathan Scott Lawrence

Shigeru Sato

Stephane Vannuffelen

Ricardo Vasques

Andrew Meredith

Jonathan Webster Brown

Mark Milkovisch

Anthony Robert Holmes Goodwin

Raymond V Nold, Iii

Akira Kamiya

Kenneth L Havlinek

Yves Barriol

Emmanuel Desroques

Masaru Niwa

Kazumasa Kato

Takenori Motoki

Hisayo Tauchi

Hidetoshi Yoshiuchi

Yukio Sudo

Yasuhiro Ohashi

Tim G J Jones

Wei-Heong Tan

A pressure transducer comprises a housing including a body section and at least one end cap at one end of the body section, which are made of piezoelectric crystal, and a piezoelectric resonator in the housing. The body section and the end cap are bonded by an atomic diffusion bonding method.

Pressure transducer and method for fabricating the same

A gas separation and detection tool for performing in situ analysis of borehole fluid is described. The tool comprises a sampling chamber for a downhole fluid. The sample chamber comprises a detector cell with an opening. The tool also comprises a gas separation module for taking a gas from the downhole fluid. The gas separation module comprises a membrane located in the opening, a support for holding the membrane, and a sealant applied between the housing and the membrane or support. Moreover, the tool comprises a gas detector for sensing the gas.

Detecting gas compounds for downhole fluid analysis

An improved manufacturing process for resonator-based pressure transducers is described. The process is a batch process in which several resonators are shaped simultaneously, using an etching process such as plasma etching. The end pieces are also shaped, if required, for several transducers. The end pieces and resonators are sandwiched together prior to separating the individual transducer units. The individual transducer units are then separated using a cutting process. The described process can be used to manufacture pressure transducers having a substantially smaller size, for example 5-6 mm outer dimensions and 2-3 mm resonators. The outer shape of the transducers can be a non-circular cylindrical shape such as that of a right square prism or an octagonal prism.

Low cost resonator-based pressure transducer

Vibrating wire viscometers are disclosed. An example vibrating wire viscometer includes first and second electrically conductive tubes, where the first tube is at least partially inserted into the second tube, and where the first and second tubes are coupled via an electrically insulating bonding agent. The example viscometer further includes first and second electrically conductive pins inserted into respective ones of the first and second tubes, and an electrically conductive wire fastened to the first and second pins to vibrate in a downhole fluid to determine a viscosity of the downhole fluid.

Vibrating wire viscometers

A pressure transducer for high-pressure measurements comprising a housing and a piezoelectric resonator located in the housing, wherein the resonator comprises double rotation cut piezoelectric material configured or designed for vibrating in the fundamental tone of dual modes of the fast and slow thickness-shear vibrations.

Pressure transducer

Vibrating wire viscometers are disclosed. An example apparatus to determine the viscosity of a downhole fluid is described, the apparatus including a wire to be immersed in a downhole fluid, to vibrate when an alternating current is applied to the wire within a magnetic field, and to generate an electromotive force when vibrating within the magnetic field, the wire comprising a first resistance. The apparatus further includes a nulling circuit coupled to the wire, wherein the nulling circuit comprises a second resistance that is selectable to be substantially equal to the first resistance, and an analyzer coupled to the wire and the nulling circuit to determine the first resistance, the second resistance, and a viscosity of the downhole fluid based on the first and second resistances, at least one characteristic of the wire, and the electromotive force.

Methods and related systems are described for a sealed housing for downhole transducers. The housing system includes a housing body and a transducer positioned within the housing body, and one or more flexible members sealably mounted on the housing body. The flexible members each have one or more undulations which facilitate movement of the flexible member in directions primarily perpendicular to the surface of the flexible member. The dimensions of the one or more undulations are designed so as to optimize the ability of the movements of the member thereby accommodating volume changes in the sealed housing. A substantial amount of compensating material can also be positioned within the housing body. The compensating material has a coefficient of thermal expansion substantially less than that of the housing material.

Packaging for downhole pressure transducers

An electrochemical sensor for measuring contents of a fluid or gas at high pressure and/or high temperature, for use, for example, in a wellbore for hydrocarbon applications, is provided. The sensor includes: a bulkhead-like electrode assembly including a cylindrical housing and a cylindrical electrode structure. The cylindrical electrode structure includes a cylindrical conductive pin extending from a high pressure region to a low pressure region and an electrode connected to one end of the pin at the high pressure region and having an electrode surface for exposure to a flow path of the fluid or gas in the high pressure region. At least a part of the surface of the pin is protected from direct contact with the fluid or the gas by an insulating coating impermeable to the fluid or gas. The pin may include an alternating pattern of protruding and receded portions.

Electrochemical sensor

Techniques for reduced contamination formation evaluation are provided. The techniques relate to drawing fluid into a downhole tool positionable in a wellbore penetrating a subterranean formation having a virgin fluid and a contaminated fluid therein. Fluid is drawn into at least two inlets for receiving the fluids from the formation. At least one evaluation flowline is fluidly connected to at least one of the inlets for passage of the virgin fluid into the downhole tool. At least one cleanup flowline is fluidly connected to the inlets for passage of the contaminated fluid into the downhole tool. At least one fluid circuit is fluidly connected to the evaluation flowline and/or cleanup flowlines for selectively drawing fluid therein. At least one fluid connector is provided for selectively establishing a fluid connection between the flowlines. At least one sensor is provided for measuring downhole parameters in one of the flowlines. Fluid may be selectively pumped through the flowlines to reduce the contamination in the evaluation flowline.

Apparatus and method for formation evaluation

A pressure- and temperature-sensitive transducer comprises a tubular housing, a resonator located within the housing and end caps closing the ends of the housing. The resonator is located in a radial plane with respect to the housing and is connected to the housing by two separate connecting regions. The housing, resonator and connecting, regions are formed from a single piece of double rotation cut quartz. The shape, dimensions and position of the connecting regions is chosen to optimize stress in an axis responsive to changes in pressure and temperature while minimizing stress in an axis responsive predominantly to pressure.

Pressure and temperature transducer

A pressure and temperature transducer includes an elongate housing formed from double rotation cut crystal quartz, an elongate plate-like resonator formed from double rotation cut crystal quartz capable of vibrating under an applied electric field located within the housing, the resonator being formed in unitary construction with the housing. The long edges of the resonator are connected to the interior walls of the housing, and short edges of the resonator are free and extend across the interior of the housing in a substantially continuous curve. Electrodes are located on opposite faces of the resonator for applying an electric field which causes the resonator to vibrate. End caps, formed from double rotation cut crystal quartz, are provided at each end of the housing. A borehole tool includes a tool body which can be positioned in a borehole, a probe for sampling fluid in the borehole; and a pressure and/or temperature transducer, connected to the probe for making measurements on the fluid.

A dual-mode thickness-shear quartz pressure transducer includes a unitary piezoelectric crystal resonator and cylindrical housing structure wherein the resonator is located on a median radial plane of the housing and the exterior of the housing is provided with a pair of parallel flat surfaces which are located at an angle relative to the X' axis of the resonator. According to the presently preferred embodiment, the transducer is made from an SC-cut or a WAD-cut solid quartz crystal cylinder which is ultrasonically milled to form a plano-convex or bi-convex resonator disk in the medial radial plane of a hollow cylinder and the pair of exterior flats. The wall thickness of the cylinder is altered at the location of the flats such that stresses at the center of the resonator disk are anisotropic. According to the invention, the ratio of the stresses at the center of the resonator disk along the X' and Z' axes are optimized such that the pressure sensitivity of the third thickness harmonic of C mode vibration is maximized. Optimization of the ratio of the stresses along the X' and Z' axes is accomplished in particular by altering the (azimuthal) angle of the flats. According to a presently preferred embodiment of the invention, the flats are located at an azimuthal angle of approximately 134.degree. relative to the X' axis of a WAD-cut resonator.

Dual-mode thickness-shear quartz pressure sensors for high pressure and

Growing community of inventors

Yokohama, Japan

Noriyuki Matsumoto