Operators Ranked

100

Combined Wells

215,102

Recent Permits (24mo)

9,239

Combined DUCs

24,547

#	Operator	Wells	Permits 24mo	DUCs	Producing	Top Formation	Top County
1	Chevron	59,413	2,480	7,359	36,604	San Joaquin Basin	Kern
2	Aera Energy	57,796	2,167	7,401	39,119	Monterey-Temblor	Kern
3	California Resources Production	15,269	765	1,327	8,936	San Joaquin Basin	Kern
4	Sentinel Peak Resources Ca	10,942	762	1,293	7,764	Monterey-Temblor	Kern
5	Berry Petroleum Company	8,431	842	793	6,331	Monterey-Temblor	Kern
6	California Resources Elk Hills LLC	7,561	889	353	6,760	Monterey-Temblor	Kern
7	Tidelands Oil Production Company	4,172	69	285	1,652	Monterey	Los Angeles
8	E & B Natural Resources Management	4,072	154	467	2,711	San Joaquin Basin	Kern
9	Union Oil Company Of California	2,561	0	143	761	Monterey	Santa Barbara
10	Shell Oil Company	2,501	4	295	315	Monterey	Kern
11	Crimson Resource Management	2,271	130	368	1,497	Monterey-Temblor	Kern
12	Calnrg Operating LLC	2,223	83	136	1,634	Monterey	Ventura
13	Thums Long Beach Company	2,124	92	145	1,606	Monterey	Los Angeles Offshore
14	Mobil Oil	1,926	0	272	199	Monterey	Los Angeles
15	Exxon Mobil	1,728	0	343	631	Monterey	Los Angeles
16	Holmes Western Oil	1,410	61	86	979	Monterey-Temblor	Kern
17	Macpherson Oil Company	1,244	92	125	873	San Joaquin Basin	Kern
18	Midwaysunset Investors	1,041	1	0	29	Monterey-Temblor	Og
19	Union Pacific Resources Company	966	0	13	262	Monterey	Los Angeles
20	Cat Canyon Resources LLC	887	0	9	692	Monterey	Santa Barbara
21	Bridge Energy LLC	814	16	21	533	Monterey	Orange
22	Signal Hill Petroleum	740	9	14	592	Monterey	Los Angeles
23	Phillips Petroleum Company	740	0	201	47	Monterey	Kern
24	Lost Hills	734	0	0	0	—	Og
25	Arco Western Energy	700	0	107	73	San Joaquin Basin	Kern
26	Bridgeland Resources LLC	678	53	28	533	Monterey	Los Angeles
27	Carbon California Operating Company LLC	667	6	80	553	Ventura Basin	Ventura
28	Pacific Coast Energy Company	666	24	42	457	Monterey	Santa Barbara
29	Southern Community	630	40	40	374	Monterey	Los Angeles
30	Dcor	626	33	200	400	Monterey	Santa Cruz Area
31	San Joaquin Facilities Management	587	9	8	445	San Joaquin Basin	Kern
32	Atlantic Oil Company	568	0	260	111	Sacramento Basin	Yolo
33	Bellaire Oil Company	536	8	1	474	San Joaquin Basin	Kern
34	Shadow Wolf Energy LLC	535	9	49	424	Los Angeles Basin	Los Angeles
35	City Of Whittier	525	0	3	211	Monterey	Los Angeles
36	Hunter Edison Oil Development LTD	525	4	10	509	San Joaquin Basin	Kern
37	Newbridge Resources	518	14	8	458	Monterey	Santa Barbara
38	Kern River	516	0	0	0	—	Sc
39	Warren E & P	504	4	65	361	Monterey	Los Angeles
40	West Energy Operating LLC	493	32	35	372	Monterey	Los Angeles
41	Oxy	467	2	146	36	Monterey-Temblor	Kern
42	Hathaway	465	16	11	340	San Joaquin Basin	Kern
43	Freeport-Mcmoran Oil & Gas	465	0	91	86	Monterey	Ventura
44	Naftex Operating Company	440	37	14	334	San Joaquin Basin	Kern
45	Arco Oil & Gas Company	419	0	27	23	Monterey	Santa Barbara
46	Oryx Energy Company	413	0	90	43	San Joaquin Basin	Kern
47	Kern River Holdings Ii LLC	409	12	38	322	San Joaquin Basin	Kern
48	Amerada Hess	408	0	279	45	Sacramento Basin	Solano
49	Atlantic Richfield Company	407	0	43	41	Monterey	Los Angeles
50	Cymric	388	0	0	0	—	Og
51	West Newport Oil Company	364	0	0	286	Monterey	Orange
52	Brea Canon Oil Company	355	22	19	166	Monterey	Los Angeles
53	The Termo Company	349	17	52	233	Sacramento Basin	Los Angeles
54	Venoco	330	0	129	92	Sacramento Basin	Santa Cruz Area
55	Trc Operating Company INC	312	14	4	295	San Joaquin Basin	Kern
56	Petrolud	291	22	74	207	San Joaquin Basin	Kern
57	Texaco Producing	288	0	0	2	San Joaquin Basin	Kern
58	Hvi Cat Canyon INC	282	5	15	208	Monterey	Santa Barbara
59	Sequoia Exploration	274	16	3	230	San Joaquin Basin	Kern
60	Conocophillips Company	262	0	77	15	Monterey	Los Angeles
61	Vintage Petroleum	231	0	5	8	Monterey-Temblor	Kern
62	Capitol Oil	221	0	115	101	Sacramento Basin	Solano
63	Torrance Petroleum	216	0	0	120	Monterey	Los Angeles
64	Matrix Oil	214	2	10	194	Monterey	Los Angeles
65	Wilmington	210	0	0	0	—	Og
66	Dominguez Energy	208	0	2	95	Monterey	Los Angeles
67	Nahama & Weagant Energy Company	208	0	116	61	Sacramento Basin	Yolo
68	Seneca Resources	203	0	1	1	Monterey-Temblor	Kern
69	Pacific Gas & Electric Company	194	19	63	122	Sacramento Basin	San Joaquin
70	Cmo	193	8	39	130	San Joaquin Basin	Kern
71	Sunset Oil Company	189	0	1	0	Santa Maria Basin	Santa Barbara Offshore
72	Vaquero Energy	189	0	2	10	San Joaquin Basin	Kern
73	Pyramid Oil Company	186	0	1	33	Monterey	Kern
74	Huntington Beach Company	180	0	0	56	Monterey	Orange
75	Saba Petroleum	179	0	0	46	Monterey	Santa Barbara
76	Sycamore Development Partners LLC	176	125	7	134	Monterey	Orange
77	J P Oil Company	173	7	1	85	Monterey-Temblor	Kern
78	State Lands Commission	172	2	46	96	Monterey	Ventura Offshore
79	Tesoro Petroleum	171	0	25	0	San Joaquin Basin	Kern
80	Santa Fe Energy Resources	169	0	38	7	San Joaquin Basin	Kern
81	Trico Industries	168	0	65	0	San Joaquin Basin	Kern
82	Marathon Oil Company	167	0	33	6	Monterey-Temblor	Kern
83	Drilling & Production Company	161	2	10	70	Monterey-Temblor	Kern
84	Angel Petroleum LLC	160	0	12	84	Monterey	Santa Barbara
85	Royale Energy	159	1	42	96	Sacramento Basin	Colusa
86	Oro Negro INC	158	0	10	106	San Joaquin Basin	Kern
87	Rosetta Resources Operating	157	0	54	91	Sacramento Basin	Yolo
88	Towne Exploration Company	153	0	59	78	Sacramento Basin	Sacramento
89	Standard Oil Company	151	0	1	43	San Joaquin Basin	Kern
90	Petrolewis	150	0	2	8	Monterey	Los Angeles
91	Inglewood	145	0	0	0	—	Og
92	Beta Operating Company	145	0	40	105	Southern California Borderlands Province	Santa Catalina Area
93	Synergy Oil & Gas	144	46	14	87	Monterey	Los Angeles
94	Txo Production	144	0	92	43	Sacramento Basin	Solano
95	Kenneth H Hunterjr Trustee Of The Hunter Livin	143	0	1	52	San Joaquin Basin	Kern
96	Trivalley Oil & Gas Company	142	5	48	31	Sacramento Basin	Kern
97	Aba Energy	139	7	52	82	Sacramento Basin	Solano
98	Triton Oil & Gas	138	0	38	71	Monterey	Los Angeles
99	Trc Operating Company Incorporated	137	0	5	108	San Joaquin Basin	Kern
100	Poso Creek	131	0	0	0	—	Og

About This Leaderboard

Source: California Geologic Energy Management Division well-header records.

Ranking: Operators ranked by total well count under their current operator-of-record. Recent permits cover the last 24 months; DUC count is wells spudded but not yet producing; producing-well count is wells with a first-production date on file.

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

Refresh cadence: Monthly. Data current as of 2026-06-14.

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