Develco, Inc.

Quantum Solutions, Inc.

Tensor Corporation

Henry S More

Louis H Rorden

Neil H Akkerman

Edward C Fraser

John L Marsh

Lawrence R Bulduc

Susanne F Vaughan

A measuring while drilling apparatus for use in the drilling of subterranean wells comprises a plurality of interconnected tubular housings which are insertable into and removable from a drill string by a wire line. A hollow plunger on the bottom of the apparatus is vertically shiftable with respect to a fixed diameter orifice disposed in the path of the drilling fluid flow. Fluid pressure forces derived from the drilling fluid effect the movement of the plunger forward and away from the orifice to create pressure pulses which are transmittable through the drilling fluid to the surface. Sensors provided in the housings generate signals, which are converted by a downhole controller, to effect the sequential generation of the positive pressure pulses to be indicated at the surface of the well by a digital readout of the outputs of the various sensors carried in the tubular housings.

Measuring while drilling system

A modified subterranean antenna structure for use in boreholes that pivotally balances a separate core member within the hollow interior of a fixed winding member in order to filter out mechanically induced vibrations from the core. The mechanical natural resonant frequency of the core is reduced and becomes less than the lowest electromagnetic signal frequency intended to be transmitted to and received by the subterranean antenna. In this way, mechanically induced vibrations will not create mechanically generated frequency signals sympathetic to the frequencies chosen for the antenna communication band frequencies.

Gimballed antenna

An apparatus employing a set of inductive coils to transmit AC data and power signals between a downhole apparatus (which may include a sensor and a safety valve) and apparatus at the surface of the earth. In a preferred embodiment, the invention inductively couples a low frequency (less than 3 KHz) AC power signal from an outer wellhead coupler coil to an inner wellhead coupler coil wound around a tubing string. The AC signal propagates down a wireline conductor along the tubing string to a first downhole coupler coil (also wound around the tubing string) and is inductively coupled from the first downhole coupler coil to a second downhole coupler coil within the tubing. The power signal is preferably rectified, and then employed to power various items of downhole equipment. Data from a downhole sensor (whose frequency is preferably in the range from about 1.0 KHz to about 1.5 KHz) is impressed on the second downhole coil to modulate the AC power signal. The modulated AC signal is inductively coupled from the second downhole coil to the first downhole coil, and from the inner wellhead coil to the outer wellhead coil, and is demodulated by phase locked loop circuitry at the wellhead to extract the sensor data.

Apparatus for inductively coupling signals between a downhole sensor and

An elastomeric body encapsulates an electronic assembly, to be protected from vibration on shock, and is confined in a closed cavity of a structure subject to the vibration and shock. The body is cast in a separate mold having a cavity corresponding in shape and size to the closed cavity. The surface of the mold has projections to form indentations in the surface of the body. With the body in the closed cavities, the indentations are effectively voids and accept elastomeric material displaced from the body when the body expands relative to the cavity. The preferred embodiment provides a strongback support with open cavities, each to receive a body. The strongback is inserted into a tube to complete the structure and close the open cavities. The strongback has wiring chambers to accept flexible leads connected to each body, and channels into which wire is potted, to extend from the leads to external circuitry. To retain the bodies in the open cavities before closing, the elastomer bodies have projections that resiliently engage cooperation surfaces in the cavities.

Vibration mount for electronic assemblies

A method and apparatus for stabilizing a communication sensor in a borehole is described. The principle embodiment described includes a pair of centralizers at opposite ends of the housing for the communication sensor to maintain each of such respective ends at a constant lateral displacement from the borehole casing. A pair of flexible joints are provided to isolate the communication sensor to decouple the component to be protected from any motion and/or forces secured to the same urging it from the centralized position.

Method and apparatus for stabilizing a communication sensor in a borehole

A system for verifying the effectiveness of electromagnetic signal control of a subsurface safety valve installed in a well. Signals are transmitted from a surface station to actuate the subsurface installed valve. Signals received at the valve are decoded and information relating to them is stored. A sensor detects actual valve actuation and provides signals indicative thereof which are also stored. After the valve is removed from its downhole installation, the stored signals are read, and the data indicated thereby is compared with data recorded at the time of signal transmission from the surface.

Growing community of inventors

Los Altos, CA, United States of America

Henry S More