Santa Clara Avenue Oil Field facts for kids
Quick facts for kids Santa Clara Avenue Oil Field |
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The Santa Clara Avenue Oil Field in Ventura County, California.
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| Country | United States |
| Region | Ventura Basin |
| Location | Ventura County, California |
| Offshore/onshore | onshore |
| Field history | |
| Discovery | 1972 |
| Start of development | 1972 |
| Start of production | 1972 |
| Peak year | 1977 |
| Production | |
| Current production of oil | 211 barrels per day (~10,500 t/a) |
| Year of current production of oil | 2009 |
| Estimated oil in place | 1.335 million barrels (~1.821×105 t) |
| Producing formations | Sespe Formation |
The Santa Clara Avenue Oil Field is a place in Ventura County, California, where oil is found deep underground. It's located about six miles southeast of Ventura and four miles northeast of Oxnard.
All the oil from this field is taken out using wells drilled from two special areas called "drilling islands." These islands are along Santa Clara Avenue. Each island has many wells that drill into the ground at an angle. The oil field is in an area mostly used for farming. However, cities nearby are growing, so buildings are getting closer to the field. In 2010, experts believed there were about 1,335,000 barrels of oil still available to be taken out. At that time, 18 oil wells were actively pumping oil.
Where the Oil Field Is Located
The Santa Clara Avenue Oil Field is in a flat, rich farming area called the Oxnard Plain. This area is slowly being surrounded by growing cities like Oxnard, Ventura, and Camarillo. You'll see oil production equipment and storage tanks right next to farm fields and fruit orchards. Farmers nearby grow crops such as onions, broccoli, and strawberries.
U.S. Highway 101 runs along the southern edge of the oil field. Santa Clara Avenue goes through the field from southwest to northeast. It ends at California State Route 118. The small town of El Rio is to the west. Nyeland Acres, another small community, is to the south, next to Oxnard. The part of the field that produces oil covers about 180 acres.
The weather here is like a Mediterranean climate. This means it has cool, rainy winters and warm, dry summers. During summer, the heat is often made milder by fog and clouds from the coast in the mornings. About 15 inches of rain fall each year, mostly in winter. The average yearly temperature is between 56 and 60 degrees Fahrenheit (13 to 16 degrees Celsius). It rarely freezes here. The field is mostly flat, about 80 feet above sea level. Water from the area flows south into Calleguas Creek, then to Mugu Lagoon, and finally into the Pacific Ocean.
How Oil Formed Here
The Oxnard area is part of the Ventura Basin Province in southern California. This whole region is like a giant bowl that sank down slowly over time. This happened during a period called the late Pliocene era. Over five million years, about seven kilometers (over four miles) of sand, mud, and other materials filled this basin. Most of these materials were from the ocean. However, some volcanic rocks from the Conejo Volcanics series are also found on top of them.
Oil often collects in the Ventura Basin. It usually gets trapped in rock layers that are folded upwards, like an upside-down U-shape. These folds are called anticlines. Sometimes, cracks in the earth called faults also help trap the oil. The way different rock layers are stacked, called stratigraphy, also plays a big role in trapping oil. When there are sandy rocks that have many tiny spaces (porosity), and the rock layers are shaped in a way that traps oil as it moves upwards, you find oil fields.
In the Santa Clara Avenue field, oil is trapped in many thin layers of oil-rich sand. These layers are part of the Sespe Formation, which is from the Oligocene age. The oil is trapped where it meets the Conejo Volcanics. These volcanic rocks are very hard and don't let oil pass through. Scientists first thought these volcanic rocks filled an ancient canyon. But now, they believe these rocks formed from hot magma that cooled quickly underground.
Because the surface of the Oxnard Plain is flat, it was hard to tell that there was oil deep below. Even though oil was found all around it – in the Oxnard Oil Field to the south, the Ventura Oil Field to the northeast, and the South Mountain Oil Field and Saticoy Oil Field to the northeast – the Santa Clara Avenue field wasn't discovered until 1972. It was found by people looking for oil near the Epworth Syncline, which is a downward fold in the rock layers.
Two main areas with oil were found. Both were in the Sespe Formation, separated by the volcanic rock. The first discovery was in January 1972, and the second was in July 1973. The oil is found very deep underground. One area is about 9,000 feet deep, and the other is about 8,600 feet deep. The oil is generally "medium-grade," meaning it's not too thick or too thin. It also has about two percent sulfur.
History and How Oil is Produced
The first well that discovered oil in this field was drilled by McCulloch Oil Corp. in 1972. Other oil companies quickly explored the area and found the second oil-rich spot about a year and a half later. Over the years, companies like Tenneco Oil Co., ARCO, Chevron, and Concordia Resources worked in the field. The most oil was produced from this field in 1977. Between 1994 and 1996, a company called Venoco bought most of the field.
All the drilling in the field happens from two special areas called drilling islands. These islands are about 100 yards away from Santa Clara Avenue. The oil that is pumped out is stored in large tanks at the southern drilling island. As of December 31, 2011, there were 17 wells actively pumping oil from the field. Two other wells were used to get rid of water that came up with the oil.
