The Rincon field runs along the Ventura County coast about ten miles northwest of Ventura and twenty miles southeast of Santa Barbara, with onshore acreage and an offshore extension reached from the artificial Rincon Island. Pan American Petroleum drilled the discovery well, Hobson Fee No. 3, in December 1927. Every producing horizon is in the Pliocene Pico Formation, and the crude is medium grade at 26 to 30 degrees API — lighter and easier to handle than the heavy oil that dominates California production statistics.
Pan American Petroleum completed Hobson Fee No. 3 in December 1927, opening a field that would eventually be developed both onshore and beneath the surf line. The Ventura coast was in the middle of an exploration wave at the time, with the enormous Ventura Avenue field already proven a few miles east, and Rincon fit the same structural story: deep Pliocene sands folded into anticlines along the Ventura Basin. Leases written in that period still govern much of the mineral ownership along this stretch of coast.
Rincon is unusual for the depth range it covers within a single formation. Producing horizons run from about 3,400 feet in the shallow pool of the western Main Area down to the third Grubb horizon at an average depth near 13,000 feet — all within the Pico Formation. Waterflooding began in 1961 and most zones were under active injection by the end of that decade. Production peaked in 1972 at more than 4.6 million barrels for the year, then declined steadily as the floods matured.
The offshore portion is reached from Rincon Island, a man-made island built off the coast to allow drilling into the seaward extension of the field, and it has been operated separately from the onshore leases. Occidental Petroleum, through its Vintage subsidiary, has operated onshore acreage, while other companies including Greka Energy have worked the island. By the 2000s the field retained only about two and a half percent of its original reserves — a heavily depleted asset in engineering terms, still producing in practice.
All of Rincon’s producing horizons lie within the Pico Formation, a thick Pliocene marine section deposited in the rapidly subsiding Ventura Basin. Depths range from about 3,400 feet in the shallow western pool to roughly 13,000 feet at the third Grubb horizon, an unusually large vertical range for one formation and a direct consequence of how fast sediment accumulated here. Traps are anticlinal, formed by the intense compression that continues to deform the Ventura Basin today. The oil is medium grade at 26 to 30 degrees API.
Waterflooding started at Rincon in 1961 and had reached most zones by the end of the 1960s, which is why the field’s peak year came in 1972 rather than in its first decade. Water injection replaces produced reservoir energy and sweeps oil toward producing wells, and in the well-sorted Pico sands it worked effectively for many years. With roughly two and a half percent of original reserves remaining, the flood is far into its late life and water handling now dominates operating cost. Injection is permitted by CalGEM.
This page addresses the onshore Rincon acreage; offshore and island operations sit under a separate regulatory and leasing regime. Onshore Rincon royalties are late-life waterflood income — medium-gravity crude with better price realization than California heavy oil, but a heavily depleted reservoir behind it. Valuation should focus on your specific leases, the current operator, and recent volumes. Owners weighing a certain sum against a thin remaining stream deserve real numbers. We buy minerals and royalties in Ventura County and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
Usually not. The onshore leases and the offshore extension worked from Rincon Island have been held and operated separately, and offshore acreage falls under a different leasing and regulatory regime. Your division order and legal description determine which side your tract is on.
By the 2000s the field was reported to retain only about two and a half percent of its original reserves. It continues to produce, but any honest valuation treats it as a late-life waterflood rather than a field with meaningful growth ahead.
Per barrel, generally yes. At 26 to 30 degrees API the oil is medium grade rather than heavy, so it avoids the steep quality discount applied to 13-gravity San Joaquin crude. The offsetting factor is a much smaller remaining volume.