Best Oil & Gas Upstream Companies in California, United States
The 34 best Oil & Gas Upstream companies in California, United States in 2026, ranked by funding and momentum. Funding, investors, founders, valuation, tech stack and live signals. Top: California Resources Corporation.
Ranked: Best Oil & Gas Upstream companies in California
| # | Company | Last round | Disclosed funding | Employees | Founded | Founder | Recent signals |
|---|---|---|---|---|---|---|---|
| 1 | Brinderson Provider of construction, maintenance and turnaround services to oil and gas industries | — | — | 341 | 1965 | Manuel Junco CEO | — |
| 2 | Macpherson Provider of oil & gas exploration & production services | — | — | 52 | 1981 | — | — |
| 3 | OS Petro Provider of telecommunication network infrastructure solutions | — | — | — | 1998 | Michael Sutton Co-Founder & CIO | — |
| 4 | Pacific Coast Energy Company Oil & gas exploration, development, and production company | — | — | 73 | 2015 | Randall Breitenbach Chairman & CEO | — |
| 5 | Pierce Oil and Gas Oil and natural gas exploration and production company | — | — | — | 2018 | Michael Pierce President & CEO | — |
| 6 | Process Instruments Provider of oil well testing and steam quality measurement system services | — | — | 35 | 1988 | — | — |
| 7 | Reabold California Provider of production and exploration services for oil and gas sector | — | — | — | — | James F Westmoreland CEO | — |
| 8 | reostar energy corporation ReoStar Energy Corporation is a mining and energy company that produces iron ore, gold, silver, copper and… | — | — | 4 | 2004 | — | — |
Top 12 Oil & Gas Upstream companies in California
#1
Public · Danville, California · founded 1983$606Kraised▾
Trio Petroleum is a California-focused oil and gas exploration and development company, with a proven history of raising capital, building companies, generating prospects, drilling wells, and economically producing discovered oil. The company operates as an oil and gas exploration and development company with a strategic focus on the California market. Trio Petroleum has a strong track record of successful operations and is poised for continued growth and development in the oil and gas industry.
- Apr 2025Post IPO$606K
#2
Seed · Los Altos, California · founded 2022 · 9 employees$3Mraised▾
Provider of oil & gas exploration and production services
- Oct 2024Seed$3M
- May 2023Seed—
#3
Public · Los Angeles, California · founded 2014 · 970 employees$1.6Braised▾
Provider of oil & gas exploration and production services
- Oct 2019Series C$500M
- 2018Series B—
- Feb 2018Series B$50M
- Mar 2017Seed—
#4
Public · Los Angeles, California · founded 2012 · 7 employees$81.1Mraised▾
Oil and gas exploration and production company
- Aug 2022Post IPO$900K
- Jun 2022Post IPO$18K
- Jul 2021Post IPO$142.7K
- Mar 2021Post IPO$22.7K
#5
Public · Thousand Oaks, California · founded 2008 · 7 employees$96.1Mraised▾
Energy company finding and exploiting energy projects in oil and gas sector. It is an energy company focused on finding and exploiting energy projects in oil, gas, and clean and sustainable energy.
- Nov 2016Post IPO$10.5M
- Nov 2010Post IPO$66M
- May 2010Post IPO$1.4M
- Nov 2009Post IPO$4.2M
#6
Public · El Cajon, California · founded 1986 · 10 employees$12.3Mraised▾
Developer of oil and gas wells, and marketer of oil and natural gas. It owns and operates wells, focusing on low-risk drilling opportunities within established fields. The company actively builds its prospect inventory through acquisitions and surveys. It provides direct management of its properties to ensure high productivity. The business model includes joint investments in multiple wells to minimize investor risk while maximizing returns.
- Aug 2016Post IPO$2.5M
- May 2016Post IPO$200K
- Oct 2009Post IPO$2M
- Aug 2009Post IPO$1.1M
#7
Deadpooled · San Diego, California · founded 2004 · 9 employees$5.2Mraised▾
Event and tourism promotion with balloons and decorations in Indonesia. They specialize in providing eye-catching promotional solutions for events and tourist destinations. Services include providing balloons for events, promotional campaigns, and decorations. They focus on creating memorable experiences through visually appealing decorations, including balloon arrangements and custom designs. They cater to event organizers and tourism businesses looking to enhance their appeal and attract more attention. They offer balloon promotional items and event decorations. They also provide consultation services to help clients choose the best options for their specific needs.
- Mar 2014Post IPO$5M
- Apr 2011Post IPO$200K
#8
Deadpooled · San Diego, California · founded 2005 · 1 employees$5Mraised▾
Kabe Exploration is an E & P Company. The company is focused on acquiring oil and gas assets, oil and gas exploration, refinery and pipeline sectors of the energy industry. The company carries out its its business in the United States.The website is non functional as of 30 Dec 2015.
- May 2013Seed$5M
#9
Deadpooled · Carlsbad, California · founded 2010$3.5Mraised▾
Hybrid Energy is an oil and gas company involved in the analysis, acquisition, and management of oil and gas properties in the Permian Basin of Texas. Also, acquire properties which are under drilling and production phase.
- Dec 2017Series A$3.5M
#10
Public · Los Angeles, California · founded 1985 · 54 employees$3.1Mraised▾
PetroQuest Energy, Inc. is an independent energy company engaged in the exploration, development, acquisition and production of oil and natural gas reserves in East Texas, Arkoma Basin, South Louisiana and the shallow waters of the Gulf of Mexico.
#11
Funding Raised · Goleta, California · founded 2018 · 7 employees$1.2Mraised▾
Developer of plant-based renewable chemical technologies. It develops sustainable alternatives to petrochemicals using biomass. These alternatives include thermoset plastics derived from lignin, a byproduct of cellulosic ethanol production. The company's technologies are applicable across various industries, such as automotive, aerospace, and sporting goods. Its research focuses on creating recyclable and environmentally friendly polymers and plastics. The company also explores bio-based applications, such as converting natural extractives into flavoring products. Its process engineering expertise ensures efficient scaling of technologies from research to commercial production.
- Sep 2017Grant (prize money)$100K
- Feb 2014Grant (prize money)$1.1M
#12
Public · Newport Beach, California · founded 2011 · 3 employees$80Kraised▾
Citadel Exploration is an exploration and production company which is operating in Kern County of California which has 1100 acreage positions and an estimated 60 million BOE of oil reserves.
- Aug 2012Seed$80K
Funding & investor landscape
Notable founders
Market landscape — 10 sub-themes by coverage
Share of Oil & Gas Upstream coverage by sub-theme.
Regulatory-risk over time rising
Funding & growth over time
funding rising · growth rising
Common questions
Riya reads income statements for fun. She covers the real money in a sector — revenue, growth, who actually earns — and never met a vague claim she didn't want a number for.