Largest Oil & Gas Operators in California 2026 — Top 100 by Wells Operated

Name: Top California Oil & Gas Operators Leaderboard
Creator: Buckhead Energy

Operators Ranked

100

Combined Wells

215,307

#	Operator	Wells	Producing	Top Formation	Top County
1	Chevron	59,408	36,624	San Joaquin Basin	Kern
2	Aera Energy	57,838	39,151	Monterey-Temblor	Kern
3	California Resources Production	15,288	8,947	San Joaquin Basin	Kern
4	Sentinel Peak Resources Ca	10,944	7,768	Monterey-Temblor	Kern
5	Berry Petroleum Company	8,439	6,331	Monterey-Temblor	Kern
6	California Resources Elk Hills LLC	7,567	6,767	Monterey-Temblor	Kern
7	Tidelands Oil Production Company	4,172	1,653	Monterey	Los Angeles
8	E & B Natural Resources Management	4,071	2,711	San Joaquin Basin	Kern
9	Union Oil Company Of California	2,561	761	Monterey	Santa Barbara
10	Shell Oil Company	2,503	315	Monterey	Kern
11	Crimson Resource Management	2,273	1,503	Monterey-Temblor	Kern
12	Calnrg Operating LLC	2,223	1,634	Monterey	Ventura
13	Thums Long Beach Company	2,124	1,607	Monterey	Los Angeles Offshore
14	Mobil Oil	1,926	199	Monterey	Los Angeles
15	Exxon Mobil	1,840	735	Monterey	Los Angeles
16	Holmes Western Oil	1,420	979	Monterey-Temblor	Kern
17	Macpherson Oil Company	1,244	873	San Joaquin Basin	Kern
18	Midwaysunset Investors	1,041	29	Monterey-Temblor	Og
19	Union Pacific Resources Company	966	262	Monterey	Los Angeles
20	Cat Canyon Resources LLC	887	692	Monterey	Santa Barbara
21	Bridge Energy LLC	814	533	Monterey	Orange
22	Phillips Petroleum Company	740	47	Monterey	Kern
23	Signal Hill Petroleum	740	592	Monterey	Los Angeles
24	Lost Hills	734	0	—	Og
25	Arco Western Energy	700	73	San Joaquin Basin	Kern
26	Bridgeland Resources LLC	678	533	Monterey	Los Angeles
27	Carbon California Operating Company LLC	667	553	Ventura Basin	Ventura
28	Pacific Coast Energy Company	666	457	Monterey	Santa Barbara
29	Southern Community	631	374	Monterey	Los Angeles
30	Dcor	626	400	Monterey	Santa Cruz Area
31	San Joaquin Facilities Management	587	445	San Joaquin Basin	Kern
32	Atlantic Oil Company	568	111	Sacramento Basin	Yolo
33	Bellaire Oil Company	536	474	San Joaquin Basin	Kern
34	Shadow Wolf Energy LLC	535	424	Los Angeles Basin	Los Angeles
35	City Of Whittier	525	211	Monterey	Los Angeles
36	Hunter Edison Oil Development LTD	525	509	San Joaquin Basin	Kern
37	Newbridge Resources	518	458	Monterey	Santa Barbara
38	Kern River	516	0	—	Sc
39	Warren E & P	504	361	Monterey	Los Angeles
40	West Energy Operating LLC	493	372	Monterey	Los Angeles
41	Hathaway	465	340	San Joaquin Basin	Kern
42	Oxy	464	36	Monterey-Temblor	Kern
43	Freeport-Mcmoran Oil & Gas	464	86	Monterey	Ventura
44	Naftex Operating Company	440	334	San Joaquin Basin	Kern
45	Arco Oil & Gas Company	419	23	Monterey	Santa Barbara
46	Oryx Energy Company	413	43	San Joaquin Basin	Kern
47	Kern River Holdings Ii LLC	410	322	San Joaquin Basin	Kern
48	Amerada Hess	408	45	Sacramento Basin	Solano
49	Atlantic Richfield Company	407	41	Monterey	Los Angeles
50	Cymric	388	0	—	Og
51	West Newport Oil Company	364	286	Monterey	Orange
52	Brea Canon Oil Company	355	166	Monterey	Los Angeles
53	The Termo Company	349	233	Sacramento Basin	Los Angeles
54	Venoco	330	92	Sacramento Basin	Santa Cruz Area
55	Trc Operating Company INC	308	294	San Joaquin Basin	Kern
56	Petrolud	291	207	San Joaquin Basin	Kern
57	Texaco Producing	288	<3	San Joaquin Basin	Kern
58	Hvi Cat Canyon INC	282	208	Monterey	Santa Barbara
59	Sequoia Exploration	274	231	San Joaquin Basin	Kern
60	Conocophillips Company	262	15	Monterey	Los Angeles
61	Vintage Petroleum	231	8	Monterey-Temblor	Kern
62	Capitol Oil	221	101	Sacramento Basin	Solano
63	Torrance Petroleum	216	120	Monterey	Los Angeles
64	Matrix Oil	214	194	Monterey	Los Angeles
65	Wilmington	210	0	—	Og
66	Dominguez Energy	208	95	Monterey	Los Angeles
67	Nahama & Weagant Energy Company	208	61	Sacramento Basin	Yolo
68	Seneca Resources	203	<3	Monterey-Temblor	Kern
69	Sycamore Development Partners LLC	193	134	Monterey	Orange
70	Cmo	193	130	San Joaquin Basin	Kern
71	Vaquero Energy	189	10	San Joaquin Basin	Kern
72	Sunset Oil Company	189	0	Santa Maria Basin	Santa Barbara Offshore
73	Pacific Gas & Electric Company	187	117	Sacramento Basin	San Joaquin
74	Pyramid Oil Company	186	33	Monterey	Kern
75	Huntington Beach Company	180	56	Monterey	Orange
76	Saba Petroleum	179	46	Monterey	Santa Barbara
77	J P Oil Company	173	85	Monterey-Temblor	Kern
78	State Lands Commission	172	96	Monterey	Ventura Offshore
79	Tesoro Petroleum	171	0	San Joaquin Basin	Kern
80	Santa Fe Energy Resources	169	7	San Joaquin Basin	Kern
81	Trico Industries	168	0	San Joaquin Basin	Kern
82	Marathon Oil Company	167	6	Monterey-Temblor	Kern
83	Drilling & Production Company	161	70	Monterey-Temblor	Kern
84	Angel Petroleum LLC	160	84	Monterey	Santa Barbara
85	Royale Energy	159	96	Sacramento Basin	Colusa
86	Oro Negro INC	158	106	San Joaquin Basin	Kern
87	Rosetta Resources Operating	157	91	Sacramento Basin	Yolo
88	Towne Exploration Company	153	78	Sacramento Basin	Sacramento
89	Standard Oil Company	151	43	San Joaquin Basin	Kern
90	Petrolewis	150	8	Monterey	Los Angeles
91	Beta Operating Company	145	105	Southern California Borderlands Province	Santa Catalina Area
92	Inglewood	145	0	—	Og
93	Txo Production	144	43	Sacramento Basin	Solano
94	Synergy Oil & Gas	144	87	Monterey	Los Angeles
95	Kenneth H Hunterjr Trustee Of The Hunter Livin	143	52	San Joaquin Basin	Kern
96	Trivalley Oil & Gas Company	142	31	Sacramento Basin	Kern
97	Trc Operating Company Incorporated	141	109	San Joaquin Basin	Kern
98	Aba Energy	139	82	Sacramento Basin	Solano
99	Triton Oil & Gas	138	71	Monterey	Los Angeles
100	Poso Creek	131	0	—	Og

About This Leaderboard

Source: Buckhead Energy analysis of public oil and gas data.

Ranking: Operators ranked by total well count under their current operator-of-record. Producing-well count is wells with a first-production date on file. Drilling activity (permits, spuds, DUCs) is published only as state and county counts, never attributed to an operator.

Why it matters: Knowing who operates the most wells in California helps mineral owners understand who they're dealing with at the lease level.

Refresh cadence: Daily. Data current as of 2026-10-02.

Frequently Asked Questions

Who is the biggest oil company in California?

By wells operated, Chevron is the largest oil and gas operator in California, with 59,408 wells on record per Buckhead Energy analysis of public oil and gas data. Note that "biggest" by revenue or market capitalization can rank differently — this measures operated well count.

What are the top 10 oil companies in California by wells operated?

The top 10 operators by operated well count are: Chevron, Aera Energy, California Resources Production, Sentinel Peak Resources Ca, Berry Petroleum Company, California Resources Elk Hills LLC, Tidelands Oil Production Company, E & B Natural Resources Management, Union Oil Company Of California, Shell Oil Company. The full top-100 ranking with well and producing-well counts is in the leaderboard below.

Who operates the most oil and gas wells in California?

Chevron operates the most wells in California at 59,408, per Buckhead Energy analysis of public oil and gas data.

How many oil and gas operators are ranked here?

This leaderboard ranks the top 100 operators active in California by total well count. Many more file with the regulator; these are the largest by operated wells.

Is this ranking by revenue or by wells operated?

By wells operated — the count of wells under each company's current operator-of-record designation in the public oil and gas data Buckhead Energy analyzes. It is not a revenue, production-volume, or market-capitalization ranking.

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