Dr. Steven M. Goolsby


Dr. Goolsby is a Geologist and Petrophysicist with over 28 years of industry experience in the oil and gas industry. He is a Certified Petroleum Geologist (#4053) through the Division of Professional Affairs of the American Association of Petroleum Geologists and is a Registered Professional Geologist (PG-1927) through the State of Wyoming. Principle areas of interest include:

  • Digital geophysical log analysis (shaly sandstone, multi-mineral complex lithology, thin
 bed, unusual environmental conditions)

  • Rock to log petrophysical integration (core analysis, visual rock parameters)

  • Neural network geophysical log curve and resistivity inversion modeling
  • Geophysical log modernization
  • Digital log database verification and quality control

  • Image log analysis
  • Development and instruction of industry courses and core workshops

  • Project management and supervision
  • Reservoir studies (primary, secondary recovery, unitization)

  • Expert testimony (trial, depositions, oil and gas hearings)

  • Prospect and play generation and evaluation

  • Property evaluation and appraisal
  • Formation damage evaluation and remedial recommendations

  • Petrographic studies (SEM, EDX, thin section, x-ray diffraction, cuttings)
  • Basin stratigraphic and sedimentological studies and mapping

  • Hydrodynamic and reservoir compartmentalization subsurface pressure studies
  • Reservoir simulation studies (Black Oil)
  • Pervasive gas pressure cell mapping and appraisal

  • Coalbed methane property evaluation and appraisal

  • Coal property mine site evaluation and appraisal

  • Geological well-site supervision (horizontal, vertical, coal, coalbed methane)

  • Core description and rock cuttings studies

  • Surface geological field work and mapping


1981 to Present - Co-founder and President, Goolsby Brothers and Associates, Inc. (GBAI), Denver, Colorado

A Colorado corporation that furnished a diverse array of geological consulting services to the oil and gas, coal, mineral and environmental industries. These services include petrophysical investigations, basin stratigraphic and sedimentologic studies, generation and appraisal of exploration and development potential, and detailed property evaluations. Expert testimony in court or before commissions is often furnished on the projects. Responsibilites as President include full corporate management and the supervision of all petrophysical and geological studies. In addition, Goolsby Brothers and Associates, Inc., is the licensed Rocky Mountain sales representative for Powerlog digital log analysis software.

GBAI has completed projects in almost every province of the United States, including work in the offshore and onshore Gulf of Mexico, the Eastern U.S., the Midcontinent, the Rocky Mountains, the Basin and Range, the Southwest, and the West Coast regions. International onshore and offshore study areas include Canada, South America, Europe, North Africa, West Africa, Russia, China, and New Zealand.

During a three and a half year period in the late 1990s, Mr. Goolsby served as an in-house petrophysical consultant for Amoco Production Company. Duties included log database management, data verification, data assimilation, rock-log integration, and detailed petrophysical analysis. Much of the work involved resistivity inversion processing and neural network modeling. GBAI continues to perform petrophysical work for BP-Amoco on an on-going basis at this time.

GBAI uses the Powerlog Log Analysis Software system for digital log analysis. Resistivity and spontaneous potential inversion and neural network modeling are preformed using software from Petroleum Software Technologies of Denver, Colorado. Geological studies are completed using Geoplus Petra software.

Most of the petrophysical projects completed by GBAI involve complex reservoir problems such as multimineral complex lithologies, thin-bedded pays, fracture pore networks, shaly sandstone zones, chalks, or carbonate bimodal or trimodal pore systems. We routinely handle petrophysical analysis in areas of adverse environmental conditions such as those with oil invert drilling fluids, heavily barite weighted muds, multiple tool pulls, extreme wellbore wash-out conditions, high-temperature regimes, highly deviated wells, or fresh-water formation fluids. We specialize in working with older vintage log suites and eastern style geophysical tools. Geophysical log modernization techniques are often necessary to complete the projects. The studies often involve several hundred wells containing multiple stacked pay formations. Examples of some of the projects completed by GBAI are listed at the end of this curriculum.

1981 to 1988 - Exploration Geologist, American Hunter Exploration, Inc., Denver, Colorado

Exploration geologist seeking hydrocarbon opportunities larger than 50 million barrels of oil or 100 billion cubic feet of gas in size. Major projects were initiated in the western United States, Canada, and in all major basins in the Rocky Mountain region. The position required the supervision and integration of all phases of exploration work, including those involving petrographic studies, geophysical log analysis, subsurface fluid appraisals, geophysical evaluations, stratigraphic analysis, and determination of depositional environments. Studies often focused on by-passed production potential in damaged reservoirs, particularly in basin-centered tight gas sandstone reservoirs. Coal-bed methane appraisals of the eastern U.S. and Rocky Mountain basins were also conducted.

1980 to 1981 - Geological Wellsite Supervision, Aquarian Consultants, Ltd., Denver, Colorado

Wellsite geological supervision in the western United States. Duties included petrographic examination, mud gas appraisal, drill-stem test supervision, geophysical log evaluation and recommendations on well completions.

1978 to 1980 - Coal Geologist, Colorado Geological Survey, Denver, Colorado

Coal geologist in charge of two projects to evaluate the coal deposits in the state of Colorado. An appraisal of the coking coal deposits in the state was performed in one project. The second project was a coalbed methane evaluation of the Colorado portion of the San Juan Basin.

1977 to 1978 - Uranium Exploration Geologist, Geoexplorer Associates, Inc., Denver, Colorado

Uranium exploration geologist pursuing minable deposits in the Powder River Basin of Wyoming and in eastern North Dakota.

1976 to 1977 - Coal Geologist, U.S. Geological Survey, Denver, Colorado

Coal geologist performing field mapping of deposits in central Utah and field supervision of coal coring operations in the Powder River Basin.


PhD , Geology, (Petroleum Engiineering minor), Colorado School of Mines, 2004

AAPG Gus Archie Named Scholarship

AAPG Grant in Aid

Burlington Resources Fellowship

Mobil Oil Company Fellowship

B.S. , Geology, Stephen F. Austin State University, 1975

Graduated with honors
Sigma Gamma Epsilon - national earth science honorary society

Alpha Chi - national honorary scholastic society


Society of Petroleum Engineers

Certified Petroleum Geologist #4053, Division of Professional Affairs of AAPG

Registered Professional Geologist PG-1927, Wyoming (since 1975)

American Association of Petroleum Geologists

Secretary/Editor, House of Delegates, 2003
Delegate, 2003-2005

Employment Chairman, 2001 Annual Convention

Continuing Education Chairman, 1995 Annual Convention

Rocky Mountain Association of Geologists

Distinguished Service Award, 1992
Second Vice President 2003
Continuing Education Chairman 1987-1993, 2003
First Vice President 1988
Guidebook Editor 1988

Society of Petroleum Engineers of AIME

Society of Professional Well Log Analysts

Denver Well Log Society


Goolsby, S.M., and M. W. Longman, eds., 1988, Occurrence and petrophysical properties of carbonate reservoirs in the Rocky Mountain Region: Rocky Mountain Association of Geologists 1988 Guidebook, p. 474.

Goolsby, S. M., L. Druyff, and M. S. Fryt, 1988, Trapping mechanisms and petrophysical properties of the Permian Kaibab Formation, south-central Utah, Occurrence and petrophysical properties of carbonate reservoirs in the Rocky Mountain Region: Rocky Mountain Association of Geologists 1988 Guidebook, p 192-210.

Goolsby, S. M., E. B. Coalson, and M. H. Franklin, 1994, Subtle seals and fluid-flow barriers in carbonate rocks: Rocky Mountain Association of Geologists 1994 Guidebook, p.45-58.

Goolsby, S. M., E. B. Coalson, and M. H. Franklin, 1994, Petrophysical constraints in the evaluation of hydrodynamic and capillary pore-throat traps (abs.): AAPG 1994 Annual Convention, Official Program.

Goolsby, S.M. and M. D. Goolsby, 1994, Using brining cycles as a guide to hydrocarbon exploration in the Wolfcampian Council Grove and Admire groups (Permian), Alliance Basin, Nebraska (abs.): AAPG 1994 Annual Convention, Official Program, p. 156-157.

Montgomery, S. L., S. M. Goolsby, and D. Pierini, 1998, Permian (Wolfcanpian) Admire "C": new exploratory potential in the northern Denver Basin: AAPG Bulletin, v. 82, p. 2173-2191.

Goolsby, S. M., R. M. Slatt, and N. F. Hurley, 2001, Core and Borehole Image Log Characterization of Turbidite Sandstones in the Lewis Shale, Green River Basin, Wyoming (abs.): AAPG Bulletin, v. 85.

Goolsby, S. M., and M.H. Franklin, 2003, The modernization of old log suites (poster): AAPG 2003 Annual Convention.

Goolsby, S. M., M.H. Franklin, E. B. Coalson, and M. L. Hendricks, 2003, Contrasting hydrodynamic and capillary pore-throat trapping mechanisms to explain the Weyburn field accumulation in Saskatchewan, Canada (poster): AAPG 2003 Annual Convention.


Geophysical Log Modernization - Several large petrophysical projects have been completed by GBAI that involve geophysical log modernization techniques. These studies usually involve fields in which a majority of the wells were drilled in the 1930s to 1950s and only old ES surveys are available. Many of these fields contain several hundred wells with up to 70 individual stacked reservoirs and are problematic because of increasing water cuts. In these studies the few modern wells and core data are used in conjunction with inversion processing and neural network modeling techniques to produce a modern log suite for each well. Reservoir simulation modeling using the modernized log suites has had excellent results, with reservoir simulation volumetrics matching decline-curve volumetrics within 1% in some cases. Several large South American fields have been studied using these techniques. Log modernization has also been performed to help assess exploration potential, to aid in reservoir unitization studies, and to supply sonic and density logs for synthetic seismic traces on each well in large 3D survey areas.

Evaluation of the Undiscovered Oil and Gas Resources on the New Denver, Colorado, Airport Site - A contract with the City and County of Denver to evaluate the economic potential of the undeveloped oil and gas resources on the site of the Denver.s new city airport. More than 600 wells were studied in the area to delineate the oil and gas reserves remaining on the site. Petrophysical techniques included core description, thin section petrography, SEM work, x-ray diffraction analysis, core measured rock property to geophysical log integration, and geophysical log analysis. Geological appraisal involved the delineation of depositional environments, subsurface fluid pressure mapping, lithofacies mapping, net pay mapping, seismic integration, oil and gas reserve calculation, and assessment of geological chance-of-success (risk). Trial preparation, cross examination consultation, and expert testimony in court finalized the project.

Unitization Evaluation and Due Diligence - Additional projects include appraising the secondary recovery potential for and volumetric ownership percentage in several unitization and gas storage projects for various clients. These projects involve digital geophysical log analysis, detailed computer mapping of geological and log derived volumetric parameters, determination of participation formulas, computer aided tract-by-tract determination of reservoir volumetric, and unit ownership percentage calculations.

Cretaceous Study of the Cottonwood Creek Area, Eastern Big Horn Basin, Washakie County, Wyoming - A geological and petrophysical study of the Cretaceous Frontier and Muddy sandstones in the Cottonwood Creek Field area of Wyoming. Five producing zones were examined in more than six hundred wells. Primary objectives of the study were to establish hydrocarbon pay recognition criteria in the zones, determine pore system rock types, identify by-passed pay behind pipe, and recommend field development opportunities. Study objectives were complicated by fresh to brackish formation waters, abundant highly conductive diagenetic clays and zeolites, and complex reservoir pore systems developed in litharenites comprised of up to 70% volcanic and polymorphic quartz grains. Lithotype identification was accomplished through the integration of geophysical log analysis, rock property measurements, and depositional facies identification. Petrophysical techniques included detailed core and well cuttings descriptions, thin-section petrography, scanning electron microscope (SEM) studies, x-ray diffraction measurements, core rock property to geophysical log integration, and geophysical log analysis.

Oil and Gas Potential of Paleozoic Reservoirs in the Northern Denver Basin, Colorado, Nebraska, and Wyoming - An integrated seismic, geological, and petrophysical study for hydrocarbon exploration and exploitation in several carbonate and clastic reservoirs in the northern Denver Basin. The project incorporates seismic interpretation, core description, petrographic examination (SEM, EDX, thin-section, and visual examinations), geophysical log analysis, subsurface pressure studies, and regional geological mapping to locate opportunities in these reservoirs.

Tight Gas Sandstone and Coalbed Methane Potential of the Jicarilla Acreage Block, San Juan Basin, New Mexico - An economic assessment of the natural gas potential from coalbeds and tight sandstones in several formations on a large acreage block.

Coal Mine Site Evaluation - Several detailed geological coal property evaluations for resource appraisal and hydrological characterization. Recent studies include a mine permit study in the La Plata area of southwest Colorado and a hydrological and coal resource appraisal of the Gillette area, Powder River Basin, Wyoming.

Subsurface Fluid Pressure Study of the Horse Gulch Field Area, Piceance Creek Basin, Colorado - The use of pressure/depth plots and hydrodynamic mapping to interpret reservoir distribution in a structurally complex area.

Tight Gas Formation Appraisal in the Piceance Creek Basin, Colorado - As a subcontractor of Gustavson Associates, geological and petrophysical studies were completed to support applications for FERC "Tight Formation" designation on several gas sandstone reservoirs in the Piceance Creek Basin. Project objectives were accomplished using core data, detailed log analysis, and production mapping.

Formation Damage Evaluation of Producing Reservoirs - Petrographic studies on bit cuttings and core samples using SEM examination, thin-section petrography, EDX methods, and x-ray diffraction techniques to determine the causes of formation damage in several producing reservoir settings. These studies were conducted in a number of fields for several clients, including Amoco Production Company, and have resulted in notable cost savings or significant reserve additions. Although the majority of the studies were in tight sandstone reservoirs, a broad spectrum of damageable sandstone and carbonate reservoir pore systems have been appraised.

Instructor, Pore-throat and Hydrodynamic Trapping Core Workshop - A core workshop contrasting pore-throat and hydrodynamic trapping mechanisms taught as an "in-house" course at Amoco Production Company and publicly through the Rocky Mountain Association of Geologists.

Use of "Rock-typing" to Characterize Carbonate Reservoir Heterogeneity - United States Department of Energy Contract DE-RA22- 91BC14655 examining the Ordovician Red River Formation in the Williston Basin of Montana. Primary objective of the study is to scrutinize the effects of microlithotype variation on hydrocarbon producibility in carbonate rocks. Goolsby Brothers and Associates, Inc., is providing detailed core description, identification of depositional environments, core rock property to geophysical log integration, geophysical log analysis, and supervision of all geological aspects of the study.

Exploration for Mississippian Mission Canyon Carbonate "Buried Hills", Williston Basin, North Dakota - Supervision of an exploration play initiated by Goolsby Brothers and Associates, Inc., attempting to extend Canadian producing trends into the United States. Accumulations in these trends occur in paleotopographic and two-stage salt collapse structures. The project involves regional geological studies, lease acquisition, reservoir petrophysics, surface geochemical techniques, seismic stratigraphy, and drilling.

Horizontal Drilling Potential of the Bakken Formation, Williston Basin, Montana and North Dakota - A basinwide geologic appraisal of the potential for oil and gas horizontal drilling in an overpressured mature source rock. The 38,000 square mile area was mapped to delineate thermal maturity and stratigraphic distribution of the reservoir. Producing areas were examined in detail to delineate stratigraphic and structural controls on production. The study resulted in a 500,000+ acre leasing program and an ongoing exploration play.

Exploration for Hydrodynamically Tilted Oil Accumulations in the Permian Kaibab Limestone, Southern Utah and Northern Arizona - An exploration project for large hydrodynamically controlled accumulations in carbonate reservoirs. The study involved a structurally complex 2600 square mile area with extreme variations in subsurface reservoir conditions. Exploration was accomplished through the integration of petrographic research, petrophysical analysis, subsurface pressure investigations, and regional geological studies.

Geological Wellsite Supervision - Supervision of drilling oil and gas wells in a diverse array of reservoir settings in the western United States. Duties often encompass management of the drilling operations as well as geological interpretation. Reservoir appraisal, hydrocarbon show assessment, recommendation and interpretation of drillstem tests, and geophysical log quality control and interpretation are used to recommend either completion or abandonment of the well being supervised.