Scott Fulford, BSECE
Consulting Engineer
Executive Summary
Senior Electrical and Computer Engineer with over 22 years experience working in the Downhole Oil & Gas industry, skilled in Harsh Environment Electronics Design & Manufacturing, Downhole Power Supply Design, Magnetometer and Orientation Module Design, Directional Calibration Algorithm Design, Firmware Design, LabVIEW Software Design, Altium Designer (PCB Layout), Matlab, and Lithium Thionyl Chloride Downhole Battery Engineering.
Education
University of Texas at Austin
Bachelor of Science in Electrical and Computer Engineering (BSECE), December '97
GPA Major: 3.9
GPA Overall: 3.6
Work History
April 2018 - Present
Consulting Engineer
Harsh Environment Hardware, Embedded Firmware, and System Software Design
November 2014 - March 2018
Senior Electrical Engineer
High Temp Digital Orientation Module (OM) Design, Manufacture, and Calibration; High Temp Power Supply Design, Manufacture, and Test; Automated High Temp PCB Test Systems using LabVIEW and NI DAQ's; High Temp SPI Flash Memory Test System Design; Manufacturing Engineering; PCB Designer using Altium Designer 16; Sourcing Specialist; and Vendor Liaison.
Wore so many hats because I was the only Engineer on staff at a very small company during a major downturn in the Oil & Gas industry
Learned Altium Designer for Schematic Capture and PCB Layout
Designed a 185C Dual Power Supply PCB as an XXT MWD system drop in replacement, powering an OM. Both supplies on the PCB operated from an input voltage that could range from 15V to 52 VDC. It had an average efficiency of 85% over the entire operating temperature range (25V input, 150mA Full Load on both supplies). One of the supplies was a Buck converter producing +13.5V, the other, and the most difficult to design due to its RHPZ (Right Half Plane Zero) in the transfer function, was an Inverting Buck-Boost converter producing -13.5V. This dual supply tested under full load to 175C for 500 hours, before the test was stopped without failure. Another test was run to 185°C for 300 hours before a capacitor failure, but this capacitor was mounted in a non-standard stacked surface mount component configuration in testing, believed to be the cause of the failure. Later revisions provided the capacitor it's own surface mount pads so it did not have to ride "piggy-back" on top of another surface mount capacitor.
Designed a 185C Sextuple Power Supply using two Flyback converters, one for digital power and one for analog power, 3 outputs on each Flyback using multiple-output flyback transformer design, employing non-dissipative snubber winding.
Designed a new Digital OM for use in the Evolution Engineering Drilling System, using the Sextuple Power Supply
Near the end, was doing all of the Engineering Technician work as well
Learned to solder HMP on 0603 resistors by hand using a hot plate
May 2012 - October 2014
Technical Advisor - Physics
Served as the Lead Directional Engineer for Sperry Drilling Services, in charge of Directional Module (DM) Calibration Processes and Directional Calibration Algorithms.
Totally revamped the DM calibration algorithms and processes more than doubling the yield. Estimated value to the company was almost $7M per year.
Filed my first ever patent for current / magnetic field cancellation of power conductors running past a set of survey grade magnetometers.
May 2010 - May 2012
Senior Electrical Engineer
Summary
Lithium Thionyl Chloride Downhole Battery Engineer and Magnetometer Hardware Engineer at Pathfinder
Worked with battery vendors, such as Electrochem and Engineered Power, and battery pack vendors, such as SWE (Southwest Electronics), in various projects involving both the new development and sustaining of downhole battery packs.
Designed a specialized high bandwidth, high sensitivity magnetometer to detect small currents in the drill collar itself. The mag was mounted eccentric, so as to force the current into the drill collar to on side to be able to detect the magnetic field flowing in the drill collar. My work was then used in an effort to create a "Short Hop" communication scheme for PZIG (Pay Zone Inclination and Gamma).
July 2008 - May 2010
Product Engineer
Sustaining Engineer for all Directional Modules, up to 185°C and Lithium Thionyl Chloride Downhole Battery Engineer
Managed a Lithium Thionyl Chloride Downhole battery production crisis, where a single supplier was being used and the supplier lost their recipe. It all started when the incidence of leaking batteries skyrocketed out of the norm. It was the finding of further production screening that 25% of all cells were all leaking Thionyl Chloride when exposed to 185°C for the first time. Thionyl Chloride is on the level of a nerve agent, very dangerous stuff, not to mention putting it in a sealed can with some Lithium metal alloy, and heating it up to 185°C. Worked with SWE to get a second source as quickly as possible, and, simultaneously, worked vigorously with the primary battery vendor on their corrective action plan.
Redesigned the magnetometer drive and demodulator electronics aiming for reduced component count; linear, repeatable behavior to 185C; Survivability to 200C, a lifetime at 185C of at least 400 hours intermixed with at least 20 thermal cycles from one to the other temperature extreme (-55C to 185C); 30 g RMS vibration; 1000 g Shock, all while maintaining excellent orientation accuracy (+/- 0.1° Inclination, +/- 0.2° Azimuth, +/- 0.5° Highside Toolface).
Feb 98 - June 2008
Directional Engineer
Allied Signal, Honeywell, then GE Tensor
Summary
Magnetometer and Orientation Module Design, Production, and Calibration.
Highlights
Fixed a longstanding problem with the scale factor stability of the magnetometer sensors. One of the multiple root causes was that the sensor bobbin material was hygroscopic (it absorbs water) and would grow larger in size in the presence of moisture. This places pressure, thus displacing the sensor's solenoid feedback winding enough to throw off the scale factor calibration of the magnetometer. I identified a new bobbin material, which through rigorous DOE (Design Of Experiments) testing was statistically proven to be a superior material at temperatures above 100°C, the boiling point of water.
Performed Sustaining Engineering on the Pulser Drivers and the OM's
Learned TFC from Phil Walters, one of the authors of the 1989 SPE paper previosly mentioned. Took the algorithm to the next level by introducing the concept of using derivatives to make the next guess at the coefficients more accurate, giving the iterative algorithm a stronger convergence and lower residual errors.
First learned PCB layout at Tensor. Layed out out several PCB's including a 3 channel, 3 Hz, Butterworth low pass filter that worked to 185°C for use in the NAVI185 project for Baker Hughes. Also laid out a set of magnetometer PCBs incorporating the use of Metal Foil resistors in for the scale factor resistors, thereby increasing the scale factor stability even further.