Sondex Limited

Groundflow Limited

Lucas + Co.

William Peter Stuart-Bruges

Thomas Lempriere Searight

Guy Harvey Mason

Michael Yuratich

Alan Thomas Fraser

Richard Hedley Clarke

Victor Laing Allan

Neil G Harris

Ian Hitchcock

Andrew P Bridges

Philip Anton Strong

Timothy George Boxell

John William Aiden Millar

Michael Andrew Yuratich

An apparatus for creating pressure pulses in the fluid of a bore hole is described. The preferred embodiment takes the form of a mud pulser apparatus having a signalling valve controlled by a variable pilot valve. The forces on the signalling valve are balanced and controlled by the flow of mud through the variable orifice of the pilot valve. The arrangement is such as to act like a hydraulic amplifier, and results in the signalling valve being compensated for variable flow rates. In the preferred embodiment, the pilot valve has rotary vanes that allow it to be self-cleaning.

Apparatus for creating pressure pulses in the fluid of a bore hole

A centralizer for use in oil well wireline toolstrings comprising a central mounting rod and floating spring mechanisms between which a number of jointed centralizer arms are connected. The jointed centralizer arms have a section with a concave profile disposed near to their pivot points so that a closing force acting on the arms acts at a greater distance from the pivot, thereby increasing the closing moment and making the centralizer easier to draw into a borehole with a narrow cross-section. The floating spring mechanisms also have a linkage to the presser plate of the spring such that an axial force pulling the centralizer apparatus into a borehole is transferred directly into a force on the spring, thereby reducing the opening moment the springs exert on the centralizer arms.

Centralizer for wireline tools

A shock absorbing tool for use in pipelines and oil wells, particularly in combination with perforation guns comprises a central mass supported on two springs between the end terminal members. The shock wave is absorbed in the free oscillation of the mass. The mass is constituted by a piston assembly. A steel rope permits the shock absorbing tool to be maneuvered within the bore hole without damage to the springs.

Shock absorber

A wireline logging sonde for sensing fluid properties in a bore hole. The sonde has a main body and a plurality of sensor capsules mounted peripherally to the main body on fingers. A sensor element is located in each sensor capsule. The sensor elements receive power by inductive coupling from the main body and transmit data signals at radio frequencies back to the main body.

Logging sondes for use in boreholes

A tubular cutting tool includes two or more sets of electrically actuated retractable anchoring legs mounted at longitudinally spaced apart locations and an electrically driven rotary cutting head with a retractable cutting blade. The anchoring legs can be arranged such that they are capable of compensating for variations in the internal radii of the tubular to be cut, thereby ensuring that the cutting tool is clamped rigidly in position.

Tubular cutting tool

A method and apparatus for measuring the properties such as permeability of the rock surrounding a borehole in which a directional seismic or sonic signal is generated downhole and propagated into the surrounding formation to generate an electrokinetic signal and the focus of the seismic signal is moved in three dimensions in the surrounding rock by physically moving the source or by having two seismic sources which generate oscillating seismic signals at different frequencies and the focus of the seismic signal is varied by wave interference or wave interaction.

Method for downhole logging

A device for measuring the rate of flow of fluids in a conduit is positioned within the conduit and includes a tube having two spaced part detectors which are separated by shielding units either side of them which are not in electrical contact with the detector units, when a variable electrical field is applied between the walls of the conduit and the shielding units the detector units detect discontinuities in the fluid, e.g., by detecting changes in the ratio of voltage to current and by correlating the movement of the discontinuities between the detector units, it is possible to measure the rate of flow of the fluid.

Device for measuring flow rate

A fluid density measurement device includes a float ( ) and a weight ( ), each mounted on links ( ) for essentially vertical movement. A crank ( ) is mounted above the float and weight and is connected to them,by a float link ( ) and a counterweight link ( ) to convert the forces from the float and the forces from the weight to rotational forces on the crank acting in opposite directions. The position adopted by the crank will be dependent upon the density of the fluid in which the instrument is immersed. The links ( ) are arranged so that a good approximation to straight line motion is obtained at the centre of the float and the weight.

Growing community of inventors

Hampshire, United Kingdom

William Peter Stuart-Bruges