Petroleum Resources and Industries 

 plex, three distinct and, in some instances, over- 

 turned and overthrust folds being involved. On 

 this account relatively more dry holes have been 

 drilled in this district than in any other in the 

 State. The oil comes from sands in the basal 

 McKittrick (middle Fernando), upper Miocene 

 formation. The cap rock over a part of the field 

 is middle Miocene (Monterey) shale thrust hori- 

 zontally over a nearly flat-lying upper Miocene oil- 

 sand zone. 



Midway-Sunset District — The Midway and Sun- 

 set districts are continuous and lie in the south- 

 western corner of the San Joaquin Valley, in west- 

 ern Kern County. They include about "^90 square 

 miles, or 57,117 acres, of proved oil-bearing ground, 

 probably the largest continuous area in the world. 

 There are 1274 producing wells in the two districts, 

 varying in depth from 500 to over 5000 feet. The 

 oil ranges from 11° to 29° Beaume (0.9929 to 0.8805 

 sp. gr.), and oil of 36° Beaume (0.8433 sp. gr.) 

 has been found in the Elk Hills field. The pro- 

 duction of individual wells varies from 10 to 2500 

 barrels daily, and a flush production of 58,000 bar- 

 rels daily was recorded for the famous Lake View 

 No. 1, which produced over 8,000,000 barrels in 

 eighteen months. The present average daily pro- 

 duction is 94.4 barrels. The oil comes from sands, 

 largely of upper Miocene age, in the Temblor Range 

 monocline and subsidiary anticlines developed on 

 its flank, the principal secondary folds being the 

 Elk Hills, Buena Vista Hills and Thirty-five anti- 

 clines. 



Kern River District. — The Kern River district 

 lies on the low rolling hills at the foot of the Sierra 

 Nevada, in the southeastern corner of the San 

 Joaquin Vallev. The proved territory has an area 

 of about 6400 acres, or ten square miles, having 

 an irregular elliptical form, with its longest axis 

 extending in a northwest-southeast direction. The 

 productivity of the wells within this area varies 

 with the distance from the center in a more or 

 less uniform ratio, the more productive wells be- 

 ing located near the central portion. The depth 

 to the productive oil horizons varies from 400 feet 

 on the northeast rim of the fold to 1100 or 1200 

 feet on the south and west borders. The average 

 depth of all the wells in the district will approxi- 

 mate 900 feet, and the gravity of the oil produced 

 averages about 14° Beaume (0.9722 sp. gr.). It is 

 used mainly for fuel and the manufacture of 

 asphalt. There are 1228 producing wells, their 

 average daily production per well being 15.4 bar- 



84 



