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Cawley, Gillespie and Associates, Inc.


As a petroleum consulting firm, CG&A reviews and evaluates hundreds of thousands of oil and gas properties on an annual basis worth billions of dollars. Our clients include oil and gas companies, financial institutions, midstream/pipeline companies and individual investors. With diversified experience in oil and gas producing properties throughout North America and around the globe, CG&A’s proficient team of reservoir engineers and geologists integrate geological, geophysical, engineering and economic data to produce high-quality reserve estimates and economic forecasts.


  • Texas Professional Engineering Firm (F-693)
  • Talented staff of Petroleum Engineers, Geologists, Technical Analysts, Economists, and Software Developers
  • Ability to pool resources from each office to prepare the best team for your project
  • Access to third-party experts and services for special projects
  • Deep experience in SEC, SPE-PRMS and COGEH reporting
  • Direct relationship with key SEC auditors
  • Regularly attend data rooms and assist clients with acquisitions and/or divestitures
  • Approached by all major banks, key regional banks, and private equity firms
  • Putting our clients first, since 1961
, Cawley, Gillespie & Associates
, Cawley, Gillespie & Associates


  • Analyzing wireline logs, mud & drilling logs, cores & core data
  • Subsurface interpretation and mapping
  • Structure, isopach and pore volume maps
  • Stratigraphic and structural cross-sections
  • Lithologic interpretation and facies distribution
  • Seismic interpretation and mapping
  • Reservoir characterization & geostatistical analysis
  • Volumetric reserves estimation
  • Basin and/or field geological studies
  • Unconventional reservoirs (coalbed, shale, tight sand, heavy oil)


  • Economic evaluation of petroleum properties
  • Report preparation for sales, acquisitions, mergers, estate & financing obligations
  • Fair market value determinations
  • Stock exchange filings (e.g. SEC filings & IPO evaluations, Canadian NI 51-101)
  • Probabilistic evaluations
  • Product pricing and hedging sensitivities
  • Commercial parameter estimations through LOS, plant product statements and check stub analysis
, Cawley, Gillespie & Associates
, Cawley, Gillespie & Associates

Reserve Reporting

  • Classifying and quantifying reserves & resources, and determining associated net present value.
  • Reporting can be a formal certified CGA reserve report or an audit letter commenting on the merit’s of other work
  • CGA does the heavy lifting… data gathering, organization, filtering and analysis
  • Aries or PhDWin database build out from scratch or modifying existing database
  • CGA reports are prepared in accordance with the most appropriate industry reserves and resources guidelines…
  • SPE-PRMS – 2007 Petroleum Resources Management System (PRMS) approved by the Society of Petroleum Engineers (SPE)
  • SEC – U.S. Securities and Exchange Commission (SEC) Regulation S-X Rule 4-10(a)
  • COGEH NI 51-101 – Canadian Oil and Gas Evaluation Handbook (COGEH), as prepared by SPEE (Calgary Chapter) and Canadian Institute of Mining, Metallurgy & Petroleum (Petroleum Society)

Acquisitions & Divestitures

  • Travel to data room and gather pertinent details from the seller’s technical staff
  • Prepare detailed data requests for critical data not supplied
  • Provide early commentary to our clients on project viability and evaluation plans
  • Prepare an independent reserves and economics evaluation, with varying levels of effort
  • Full-scale evaluation with extensive geosciences and engineering efforts
  • Scaled-down evaluation, auditing seller work product for reasonableness
  • As needed, dive deeper to look for missed opportunities (find value) or to risk overcalled or aggressive components
  • Prepare sensitivity evaluations as per client requirements
  • Pricing and escalation sensitivities
  • Probabilistic reserve estimations
  • Re-schedules of capital expenditure timing
  • Assist client with bid price and due diligence as needed
, Cawley, Gillespie & Associates
, Cawley, Gillespie & Associates

Resource Studies

  • CG&A regularly prepares volume-oriented field studies and basin analyses for investors and midstream clients
  • Our midstream clients include owners of pipelines, gathering systems and processing plants
  • Our expert technicians can investigate and determine the appropriate producing wells feeding a gathering system to allow for proper base volume modeling
  • We often assist with Joint Ventures, working with the producer and the gatherer to assess volumes and proper valuation metrics
  • We study localized regions or entire basins for clients that want to understand drilling trends, average well type curves, economic break-even analysis, and future volumes.
  • We can deliver a flexible and user-friendly volume model in spreadsheet form that will allow you to easily adjust drilling schedules, type curves and apply risk factors