Company lists · Data refreshed September 2026

Top 25 Petroleum consulting firms based in the United States

RevenueBase identified 1,479 petroleum consulting firms headquartered in the United States as of September 2026 and tracks 119,322 professional contacts across them, including 35,615 with verified work emails. Houston is the largest hub.

This list covers petroleum consulting firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 29, 2026 86% judged on-target in blind review
1,479Companies
119,322Contacts tracked
35,615Verified emails
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The 25 largest petroleum consulting firms based in the United States

Ranked by team size
Top 25 of 1,479 petroleum consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to petroleum consulting firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 202610001+53,380 contacts →

Indirect evidence

“We collaborate and engineer solutions to maximize asset value for our customers.”

Source: RevenueBase Database · checked Sep 29, 2026
2Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 202610001+29,577 contacts →

Indirect evidence

“NOV delivers technology-driven solutions to empower the global energy industry.”

Source: RevenueBase Database · checked Sep 29, 2026
3Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 20261,001-5,0002,755 contacts →

Indirect evidence

“Headquartered in Houston, Texas, Key Energy Services provides a wide array of leading edge energy production solutions and services.”

Source: RevenueBase Database · checked Sep 29, 2026
4Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 20261,001-5,0001,775 contacts →

Indirect evidence

“TGS provides advanced data and intelligence to companies active in the energy sector.”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 20261,001-5,0001,500 contacts →

Indirect evidence

“With over 70 offices in more than 50 countries located in major oil-producing provinces, Core Laboratories provides services to the world's major, national, and independent oil…”

Source: RevenueBase Database · checked Sep 29, 2026
6Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 20261,001-5,0001,262 contacts →

Indirect evidence

“FET (Forum Energy Technologies, Inc.) is a global company, serving the crude oil, natural gas, and renewable energy industries.”

Source: RevenueBase Database · checked Sep 29, 2026
7Partial evidenceDenver, CO, United StatesHQ checked Sep 29, 20261,001-5,0001,231 contacts →

Partial evidence

“Knight Piésold is an employee-owned, global consulting firm providing specialist services to the mining, power, water resources, and infrastructure industries.”

Source: RevenueBase Database · checked Sep 29, 2026
8Partial evidenceMinneapolis, MN, United StatesHQ checked Sep 29, 20261,001-5,0001,088 contacts →

Partial evidence

“Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.”

Source: RevenueBase Database · checked Sep 29, 2026
9Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 20261,001-5,0001,046 contacts →

Indirect evidence

“At Gulf Companies, we are driven by our mission to serve a vital role in the global energy industry.”

Source: RevenueBase Database · checked Sep 29, 2026
10Indirect evidenceSan Antonio, TX, United StatesHQ checked Sep 29, 20261,001-5,000770 contacts →

Indirect evidence

“Pioneer Energy Services is now Patterson-UTI”

Source: RevenueBase Database · checked Sep 29, 2026
11Indirect evidenceCleveland, OK, United StatesHQ checked Sep 29, 20261,001-5,000761 contacts →

Indirect evidence

“Cleveland Integrity Services offers support services to companies in the Energy, Telecommunications, and Power industries.”

Source: RevenueBase Database · checked Sep 29, 2026
12Indirect evidenceMetairie, LA, United StatesHQ checked Sep 29, 2026501-1,000700 contacts →

Indirect evidence

“EDG Inc.”

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceMiami, FL, United StatesHQ checked Sep 29, 2026501-1,000580 contacts →

Indirect evidence

“Somos una empresa multinacional líder en servicios de Consultoría de Oil & Gas, IT, Ingeniería, Recursos Humanos, Head Hunter y Proyectos”

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect evidenceLiberty Corner, NJ, United StatesHQ checked Sep 29, 2026501-1,000545 contacts →

Indirect evidence

“Becht partners with industrial operators across the energy and process sectors to solve complex challenges that impact safety, reliability, and profitability.”

Source: RevenueBase Database · checked Sep 29, 2026
15Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 2026201-500424 contacts →

Indirect evidence

“EnerVest is a top-tier, low-cost oil and natural gas operating company.”

Source: RevenueBase Database · checked Sep 29, 2026
16Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 2026501-1,000415 contacts →

Indirect evidence

“In 2019, Stratum Reservoir, formerly Weatherford Laboratories, became an independent and dynamic organization.”

Source: RevenueBase Database · checked Sep 29, 2026
17Indirect evidenceMissouri City, TX, United StatesHQ checked Sep 29, 2026201-500396 contacts →

Indirect evidence

“GGS provides an integrated suite of Geoscience solutions to the global oil and gas industry including high-resolution RG-3D Reservoir Grade® seismic data acquisition, Multi Client…”

Source: RevenueBase Database · checked Sep 29, 2026
18Indirect evidenceHouston, TX, United StatesHQ checked Sep 29, 2026201-500285 contacts →

Indirect evidence

“Greene’s Energy Group offers a range of support services and products to the oil and gas industry.”

Source: RevenueBase Database · checked Sep 29, 2026
19Indirect evidenceCut Off, LA, United StatesHQ checked Sep 29, 2026201-500272 contacts →

Indirect evidence

“Founded as C&D Wireline in 1968, with C&D Production Specialist joining the business in 1993, today Crosby Energy Services is a certified Women’s Business Enterprise National…”

Source: RevenueBase Database · checked Sep 29, 2026
20Indirect evidenceDallas, TX, United StatesHQ checked Sep 29, 2026201-500268 contacts →

Indirect evidence

“Reserves assessments and appraisals • Prospective resources assessments • Unconventional resources assessments • Contingent resources assessments • Reservoir simulation •…”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceMinneapolis, MN, United StatesHQ checked Sep 29, 2026201-500264 contacts →

Partial evidence

“Merjent is an environmental, restoration, and engineering consulting firm with a long history serving the energy industry.”

Source: RevenueBase Database · checked Sep 29, 2026
22Indirect evidenceSt. Louis Park, MN, United StatesHQ checked Sep 29, 2026201-500264 contacts →

Indirect evidence

“Nova Group, GBC is an international, multidisciplinary advising firm providing environmental, engineering and energy services throughout North America and around the globe.”

Source: RevenueBase Database · checked Sep 29, 2026
23Partial evidenceAustin, TX, United StatesHQ checked Sep 29, 2026201-500259 contacts →

Partial evidence

“Established in 1974, INTERA is a geosciences and engineering consulting firm focused on providing water resources and supply, environmental, mining, radioactive waste isolation…”

Source: RevenueBase Database · checked Sep 29, 2026
24Partial evidenceSpring, TX, United StatesHQ checked Sep 29, 2026201-500253 contacts →

Partial evidence

“For more than 40 years, M&H has been a trusted source for oil & gas consulting services that maximize value for clients.”

Source: RevenueBase Database · checked Sep 29, 2026
25Indirect evidencePittsfield, ME, United StatesHQ checked Sep 29, 2026201-500218 contacts →

Indirect evidence

“At Kleinschmidt, we work primarily with energy companies and government agencies in North America to protect and enhance the environment without compromising performance.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 1,479 petroleum consulting firms based in the United States

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Petroleum consulting firms based in the United States at a glance

As of Sep 29, 2026
29.8%Verified-email coverage
80.7Average contacts per company
1-10Median size (employees)
25.6%Largest-city concentration · Houston
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
758
11-50
455
51-200
189
201-500
41
501-1,000
13
1,001-5,000
17
5,001-10,000
2
10001+
4

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 1,479 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among petroleum consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “petroleum consulting firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names petroleum consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among petroleum consulting firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 35,615 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 29, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names petroleum consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many petroleum consulting firms are there based in the United States?

RevenueBase identified 1,479 petroleum consulting firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Halliburton, headquartered in Houston, tops this list with the largest team on record.

Which city has the most petroleum consulting firms?

Houston leads with 379 headquartered companies, followed by Denver (46) and Dallas (37).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 35,615 verified decision-maker contacts tracked across these 1,479 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 29, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.