California Oil, Gas, and Groundwater Program

3D Characteristics of the Aquifer System Adjacent to Lost Hills and North and South Belridge Oil Fields

Data from wells in and near the Lost Hills, North Belridge, and South Belridge oil fields were compiled and analyzed for mapping groundwater salinity and characterizing aquifer systems for this study.

Some findings from this study are:

  • Tulare aquifer thickens to the southeast from 250’ in north Lost Hills to 4000’ one mile east of South Belridge. It also thins over the producing areas along the anticlines.
  • Several individual aquifers—mainly of local extent—are present within the Tulare. These control pressure gradients and water salinity in the aquifer.
  • Depth to base of protected water increases southeastward from 350-500’ in North Lost Hills and North Belridge to 1600’ south of Lost Hills. Depth to base USDW increases very rapidly eastward from 350’ at the crest of the Lost Hills structure to 1700’ within one mile of the field boundary in the northern part of the field.
  • High salinities are observed above the Corcoran clay equivalent near historic produced water disposal ponds and in deeper layers within the Tulare aquifer in areas with water disposal wells—particularly in South Belridge and, to a lesser extent, in Lost Hills.
Explore Results

Results from this study were used to produce two 3D visualizations: depth to the base of the Tulare Formation and depth to the base of groundwater with total dissolved solids less than 10,000 milligrams per liter (depth to base 10K).