Donald L Howlett

41076443, Aug 15, 1978

Dec 15, 1976

5/750746

Donald L. Howlett - Houston TX

Texaco Inc. - New York NY

G01V 140

340 18CM

A data transmission system, for a well logging system having a logging tool logging a borehole traversing an earth formation and surface equipment adjacent to the borehole for making a well log, includes a sync word generator located in the logging tool, which periodically provides a predetermined digital signal corresponding to at least one sync word. A phase encoder located in the logging tool receives the data in serial digital form and the sync word. The phase encoder provides a phase encoded signal, corresponding to the data and to the sync word, at a predetermined frequency. A cable drive receives the phase encoded signal and provides it to a cable for transmissin up-hole. The surface equipment includes a phase decoder connected to the cable for decoding the phase coded signal to provide at a serial digital signal. An output circuit at the surface provides parallel digital signals in accordance with the serial digital signal corresponding to the sync words and the data.

41774574, Dec 4, 1979

Dec 12, 1977

5/859491

Donald L. Howlett - Houston TX

Texaco Inc. - White Plains NY

H03K 1302

340347DA

A system for playing back a wide dynamic amplitude range analog signal that is digitized in floating point word form. The word being represented in digital signal form by the general algebraic form Q=. +-. AB. sup. -N where Q represents the amplitude of the analog signal, A represents the mantissa, B indicates the radix of the number system used, N represents the number of fixed gain amplifier steps, and is the exponent of B, each word is represented by a first plurality of binary bits representing N. The playback system includes a first converter receiving a reference voltage which converts the bits representing A to an interim analog signal. A second converter converts the bits representing N to a plurality of control signals. A resistor network is connected to ground and has N number of inputs and an output. The resistor network provides a signal which is a reduction of the interim analog signal applied to one of the inputs, the reduction being determined by which input the interim analog signal was applied to.

53517555, Oct 4, 1994

Aug 2, 1993

8/100791

Donald L. Howlett - Kingwood TX

Texaco Inc. - White Plains NY

E21B 4709

166250

The steel casing of a well is deliberately magnetized with a known orientation by the passage therethrough of a tool having a demagnetizing section and a magnetizing section along with a gyrocompass section and a magnetic compass section. The casing is first demagnetized and then remagnetized with a polarization which can be determined. The two compasses establish the orientation of the remagnetized casing.

46972552, Sep 29, 1987

Jul 11, 1986

6/884830

Donald L. Howlett - Kingwood TX

Texaco Inc. - White Plains NY

H04R 2300

367146

An acoustic energy source or gun for use in an aqueous environment such as in a borehole, a well, or in open water. The apparatus, when lowered into a water occupied borehole or the like, functions to create a series of acoustic impulses without forming bubbles, as a result of the water rapidly infilling an implosion cylinder or chamber. A piston rod assembly is reciprocally mounted in each acoustic chamber and is actuated by a power source to trigger the desired sound creating series of impulses.

40644804, Dec 20, 1977

Nov 10, 1975

5/630241

Donald L. Howlett - Houston TX

Texaco Inc. - New York NY

G01V 128
H03F 114

340 155GC

An amplifying channel provides amplified signals corresponding to a received wide dynamic range analog input signal such as provided by a geophone group. A plurality of level comparators which number one less than the number of amplified signals compare the amplified signals with reference signals corresponding to a predetermined range of a desired output signal. The comparators provide outputs corresponding to the comparison to logic circuitry which develop sampling signals. The amplified signals from the amplified channel are also provided to a plurality of switches which are controlled by sampling pulses provided by the logic circuitry to sample an amplified signal within the range defined by the reference signals and provide it as the analog output signal. The analog output signal is converted to digital signals which are provided with other digital signals corresponding to the gain relationship between the analog output signal and the received analog input signal.

41124120, Sep 5, 1978

Dec 10, 1976

5/749646

Donald L. Howlett - Houston TX

Texaco Inc. - New York NY

G01V 100

340 155TS

A digital seismic telemetry system for recording seismic data from a plurality of seismic signal detectors positioned at selected detector stations. The system includes a plurality of remote units, each of which is positioned at a distinct detector station to receive seismic data from the detector at that station. The remote units each include a storage device for storing seismic data from the detector in digital form, and a remote transmitting unit for transmitting the stored seismic data from the storage device to a master recording unit for recording. A master control unit operably connected with each of the remote units controls the acquisition and the transmission of seismic data from the remote units to the master recording unit and limits the amount of data transmitted at any given time to optimize the bandwidth requirements for the data transmission.

50479920, Sep 10, 1991

Jun 29, 1990

7/546605

Donald L. Howlett - Kingwood TX

Texaco Inc. - White Plains NY

G01V 140
G01V 1143

367 31

An electromagnetic source or sources in a sonde in a well bore is caused to emit electromagnetic forces into the well casing. The electromagnetic forces cause displacement of the casing, inducing acoustic waves. The acoustic waves may be either P-waves or S-waves, depending on the type of electromagnetic source used. The response of earth formations to the acoustic waves, once detected, is used to detect fractures in the formations.

55373640, Jul 16, 1996

Feb 28, 1995

8/396295

Donald L. Howlett - Kingwood TX

Texaco, Inc - White Plains NY

G01V 140

367 57

Method and apparatus for conducting seismic surveys from a single wellbore utilizing an array of seismic detectors and an seismic source suspended downhole from the detectors on a coiled tubing. Actuation of the airgun both generates a seismic signal penetrating the adjacent lateral geological formations and a plurality of air bubbles pass up the borehole to attenuate tube wave propagation in the borehole fluid.